wavy_glass

Don't make this too complicated. You want to keep heat from escaping from your house. The fastest way it can leave is through holes or cracks. That should be priority #1 in and house.

1) Walls are important. Not as important as stopping air for escaping, but still important. The amount of heat that escapes is related to how insulating a barrier is AND the size of that barrier. Since walls are huge, there is the potential for a lot of heat to escape through them. If you don't want to / can't fix them, that is fine, but they will be a significant loss of heat.

2/3) Blown in fiberglass isn't "useless" as an insulator, but it is pretty useless in terms of stopping air movement. Since hot air rises, any tiny holes (vent pipes, holes for electrical, holes around light fixtures, gaps between boards, and especially the open wall cavities) will have warm air rushing through them. If they just blew in insulation on top of a partial floor, you can be about 99.99% certain they didn't do much to seal those gaps before hand. Adding insulation on top of what you have won't stop that problem. If you are so inclined, you can just shovel the insulation into trash bags, fix the underlying problems, and then rent a blower for the day to blow it back in. It is a labor intensive job though.

4) Are you sure he meant what you think? It is common to leave a weep hole, but then stuff a little paper towel in it. The water can still wick out, but it stops air movement.

5/6) Fix the windows/sills etc in the basement. Put a thermometer down there and keep an eye on the temp. You don't want to heat an uninsulated basement, but you may have to if the pipes are in danger of freezing.

7) Well, I guess insulating ducts depends on your purpose. There is absolutely no doubt that insulating the ducts will help more heat travel from the furnace into the livable space of your house. However, you aren't going to save any money by insulating the ducts and then cutting a big hole in one of them to let some air out.

Thanks all for the replies. You all are kind souls for weighing in to assist me.

First, I am going to post pictures later today of the attic. I'll need some help deciding on a game plan. I am determined to squeeze every rebate penny out of my improvements, to make back on subsidized materials at least some of what I spent on the audit.

Worthy: I truly appreciate your frank advice. The attic has a wooden floor. The blown-in fiberglass sits directly on top of that floor. The auditor claimed to be able to see fiberglass batts under the floor---he was looking at the cross-section of the entire floor while standing in the attic stairway. There are no knee walls in the unfinished attic.

calliope: the infrared camera showed plenty of cracks and crevices that were black. And all wall sockets were dark black. The auditor actually said that insulating the wall sockets makes "a hill of beans" difference, which I understood to mean it won't make much difference.

mainegrower: thanks for your advice, and for passing along your friends advice. I'll be interested in your thoughts on the attic pics I post later.

bill1: I am absolutely certain he said to caulk all around the storm windows to keep them tight. I have been reading a ton on these old house forums, and it doesn't take long to learn that virtually everyone says to ensure there is a space for water to weep out of the bottom of a storm. I presented him with this, and he waved it off and said use a paper towel instead. I also asked him why This Old House has at least three episodes where their energy auditor insists that people should insulate their duct work, at least with some mastic in obviously leaky spots. He said that they live in a different climate. I said, "No they don't, it's northern new england." He then said that they have an unlimited budget, so they can do everything they want. Note also that the auditor told me to have a hole cut in the MAIN duct that comes directly off the furnace. He said the basement needs to be warmer, and that in addition to doing the sills and the walls, I should add a register off the main duct of the furnace.

Again, I am going to post pics of the attic later today. I would truly appreciate it those who have weighed in would take a quick look, to help me decide what to do up there.

Thanks SO MUCH!

--WG

"Adding insulation to the walls of a previously uninsulated house is one of the easiest ways to waste a good deal of money and do real damage. Blown in insulation settles quickly and loses its effectiveness rapidly. Without a vapor barrier on the interior, moisture will enter the wall cavity, condense and cause rot."

This is oversimplified to the point of being misleading.

It depends on what type of insulation is blown in, how much paint might be on the walls (enough paint on old walls is an effective vapor barrier), what the actual weather is at the location (if you cannot fill the walls enough to move the freeze point into the wall it will still escape as vapor), etc.

Look around Building Science for details, but older structures often need a full understanding to decide how to proceed.

The evaluator sounds like a checklist type guy, not someone who really understands the hows and whys.

Wavyglass, When it's cold outside are your walls cold to the touch? How about your floors? That was the case with my 180 year old house with original windows & alum. storms. It seemed every room was chilly (I'm in New England). We found that our local natural gas supplier had a program for blown in cellulose insulation where you chose one of their recommended installers and they paid 50% of the price. So we had it done, it along with other measures has made a big difference in our heating bills & comfort. We use rope caulking at the bottom of windows & along the top where the lock is, to cut down on drafts. I hang insulated curtains over the original front door & single glass sidelights for the winter since it's seldom used. Installed those outlet inserts. Caulked every exterior hole I could find, and in one room where the floor was especially cold I installed fiberglass insulation between the floor joists in the basement. I don't think there is any ONE answer that will "solve" the problem, it's an ongoing battle with tweeks and adjustments that you are willing to make to be as tight as your particular house will let you. It just goes with the territory of old houses, keep a sweater and afghan nearby. Paul

I've now posted pictures.

Worthy and others, please lend your sage advice!

I don't mind doing things, I just want them done right.

http://picasaweb.google.com/anonymous469/BasementAttic#

Thanks!

Here is a link that might be useful: pictures of basement, attic, and biggest draft in the house

Blown fiberglass is aparticularly poor choice in an attic. Not only does it do nothing for the air leaks from below, it is blown around by the air in the attic further reducing its usefulness.

So if you choose to sweep it all up and reblow it, you will have only tackled half the problem. More efficient would be just covering what you have up there with a layer of cellulose. Since it's dense it will settle and fill many of those unseen air leaks and it will not be susceptible to convection currents in the open attic.

Here is a link that might be useful: Cellulose Insulation

worthy, does it make sense to do anything else for the air leaks/chases/bypasses in the attic? That is, should I remove fiberglass and look for places around vents or chimney or electrical boxes or whatever where expanding foam could be useful? Or is simply blowing cellulose sufficient to do the job with those and with the open wall cavities?

Thanks so much!

Well, the auditor who did our house handed us over boxes of switch plate insulators. He obviously didn't consider it a hill of beans. If you had infrared photography, that's super. You know exactly where to head with the caulk gun and expanding foam.

In general, the pictures seem to show that sealing air leaks would be the highest priority. The wall openings in the attic would be the first place I'd start. Then would come insulating the gable ends of the attic. The one picture which shows the old insulation beneath the attic floor looks more like cellulose than fiberglass. If there are holes in the attic floor, this was likely blown in as well, so you do have a depth of insulation equal to the depth of the floor joists. The added fiberglass on top is not ideal, but not exactly useless, either.

The cellar walls look to be in great shape, so adding styrofoam or another type of rigid insulation board here ought to be reasonably easy. There is some danger of freezing pipes if they run so close to the sill that they can't be protected, but cellars are very stable in temperature if sunk well into the ground. Since I heat almost entirely with wood, the furnace runs just a few times a year. The only problem with frozen pipes I've ever had was in an area were air leaked around the sill. A freeze alarm is, however, good, inexpensive insurance.

The pipe insulation by the cabinets could be replaced with foam insulation followed by a simple molding.

Yes, it does look like mice work in the first picture.

In regard to brickeyee's comments about wall insulation: Paint can work as a vapor barrier, but it does not provide one behind baseboards, window moldings, etc. A continous sheet of 4 or 6 mil polyethylene or other water impermable material stapled/taped to studs, floor and ceiling plates is necessary to provide a true vapor barrier. Settling is inevitable with fiberglass, cellulose or any other loose-blown insulation - like rust, gravity never sleeps. Foam may not settle, but it's nearly impossible to put it in correctly in a sealed wall and what do you do in the very likely event that you need to make changes/repairs to wiring or plumbing?

mainegrowner, thanks a million for your thoughts.

Do you have an opinion on what sort of insulation/sealing method to use on the the wall openings in the attic? And the gable ends of the attic (I assume you mean the gable end walls?)?

My father has been a builder near you in Maine for 30 years, and he yesterday strongly discouraged the use of cellulose. He told me that cellulose absorbs water and can rot wood. Fiberglass is all he uses. But people around here have been arguing strongly for me to use cellulose only. Not sure how to decide, so your added comments would be very helpful.

Thanks again, very very much.

"Paint can work as a vapor barrier, but it does not provide one behind baseboards, window moldings, etc."

The trim paint does the job just fine, and in an older house you are likely to find all the trim sealed to the wall with paint already.

Windows and the base board to floor joint are the next leakage spot, but you are far more likely to find cold air infiltrating from outside than any real moisture moving out.

Infiltration through leaks and gaps is the largest single problem in most older houses.

While dense pack cellulose can help some, sealing the gaps with caulk and foam are far more effective (and time consuming).

A lot of insulation contractors will argue otherwise, but I think your father is probably right about the water absorbant qualities of cellulose. Fiberglass can also become saturated enough with water to cause rot, but fiberglass is much less hygroscopic than cellulose.

As far as the gable end walls, look into a solid sheet type insulation such as styrofoam. Easy to put up, is its own vapor barrier (in most cases), and has a high R value per inch of thickness. Draw back is cost (but this is not a huge area) and the fact that fire codes may require that it be faced with sheetrock.

Doesn't matter much what's used to seal the wall openings - left over piece of styrofoam would be fine. Anything that stops the convection within the wall will do. Might be a good idea to see if there's an opening at the bottom that could be sealed. somewhere, too.

Brickeyee's comment about stopping air ifiltration is totally correct. It's a time consuming, tedious process but the results are pretty dramatic both in comfort and energy savings.

Thanks brickeyee.

I think our old house actually does not have a good trim-to-wall seal with paint. And I know some of the baseboards have gaps between them and the floor.

What materials would you recommend for sealing these up? What sort of caulking material can I use that will either be difficult to see or at least won't look terrible, given that these are very small gaps?

Thanks again for your advice!

thanks mainegrower. Sounds like I don't really need to hire insulators to come blow different stuff, just that I need to spend some time in the attic and basement doing some diy insulating/sealing.

What should I do about the vent pipe and chimney, which may be acting as air bypasses from below? Should I move the insulation away and make sure all gaps are sealed with foam (the fireplaces are walled off, so the chimney is not in use)?

Finally, when I'm done and some sections of the currently blown fiberglass have been disturbed by my presence, should I have some more fiberglass blown in, to even out and top off?

I really can't thank you all enough for helping me think through this.

Just got the auditor's report in the mail. Here's his major recommendation:

Quote:
"Currently the side walls of the home appear to be void of insulation. Because of the lack of insulation and the effects that [balloon] framing has on air infiltration, we found rampant air infiltration throughout the home. I recommend having these walls either dense pack insulated with cellulous insulation or insulated with injection foam to bring insulation levels up to R-14 for energy efficiency.

"Keep in mind that because of the way the home is framed/built (balloon framing), if the side walls are not properly dense pack insulated, the only reason to make other insulation improvements--with the exception of the foundation walls and attic tent which are large areas of heat lossis for comfort. Without doing the walls, you will not see energy savings due to the fact that there is widespread rampant air movement throughout the walls, floors, and ceilings that can not be stopped without properly dense packing the exterior walls."

Adding attic insulation is priority number 10:

Quote:
"10. Upper Attic Insulation levels currently have approximately R value of R-38 once all of the work involving the air sealing and fans is completed. I would suggest adding to the insulation in the attic space to an overall R-value of R-60 using additional cellulose insulation."

Does he mean that the attic will have R-38 ONLY after air sealing is completed. Or did he make a copyediting mistake, and he really means that we currently have R-38 and should make it R-60 after air sealing? I'll have to ask him.

Here's the strange recommendation about heating the basement:

Quote:
"Basement heat: I would suggest adding a heat register to the plenum of the furnace to heat the basement space."

Thoughts?

After a bit of research, I stumbled upon this great document:

http://www.wag-aic.org/1999/WAG_99_baker.pdf

It defends the superiority of dense-packing cellulose into walls of historical buildings. It even addresses moisture issues, and argues that it is superior to fiberglass in this respect. However, it only seems to address moisture-related issues that arise day-to-day; that is, it argues that dense-packed walls help regulate interior moisture better than fiberglass filled walls.

But what about concerns about old-fashioned water leaks? I assume that my father and mainegrower are concerned that there will be a leak, and the cellulose will absorb the water and rot the wood.

I think I'd prefer a cold house to a rotting house. Does this mean I should definitely avoid dense-packed cellulose?

The first part of the auditor's report makes it clear that he sees the chief value of the wall insulation as preventing air movement and infiltration. Balloon framing creates a long - equal to the height of the walls - channel between each pair of wall studs. Air movement within these channels is considerable due to natural convection. Fiberglass placed in these channels would do almost nothing to slow down air movement, so the choice of dense pack cellulose or foam does make sense. If all these channels are open in the attic, adding the insulation might not require any drilling. Simply closing off the open ends of the channels will help somewhat.

As far as the moisture issue is concerned, a house puts gallons and gallons of moisture into the air every day through cooking, showers, etc. When there is no continuous vapor barrier, this will enter the walls and insulation. Perhaps dense pack cellulose has been perfected so that it is highly moisture resistant, but I'd certainly want some guarantee of this. I'd also want to see how it can be truly dense packed within existing walls. This is pretty easy to do when walls are open, but I don't realy see how sufficient pressure can be used within a closed wall cavity. Old fashioned water leaks would create a mess and necessitate extensive repairs no matter what. It's the subtle daily accumulation of moisture laden interior air that creates the problems.

None of this negates your father's preference for fiberglass. In modern non-balloon framing each pair of studs forms a bay that is sealed at top and bottom. A material such as Tyvek prevents air infiltration from the outside. The fiberglass comes with an integral interior vapor barrier or one is added in the form of a continuous sheet of plastic. Under these conditions, fiberglass, especially in a humid climate, remains an excellent choice.

hi wavy-glass. I'm late to the discussion and far from an expert, but we've been in our balloon framed house for five years. I thought our experiences might be useful to you. Ours is just over 100 years old and had zero insulation and zero weatherproofing when we bought it. The first winter we lived here was a pretty brutal experience.

Here is what we've done so far: when we had the house painted, our painter caulked around all of the windows and door openings from the outside (he couldn't see that it had ever had caulk before). We added wood storm windows with weep spaces at the bottoms. We had chimney caps added. We pulled the quarter rounds off all the baseboards, filled the gaps between baseboards and floor with styrafoam rope insulation and/or caulk and re-installed the quarter rounds. We also used the rope insulation to fill any gaps in the double hung windows that didn't close properly. We insulated the sill plates in the basement with fiberglass bats. We installed the bronze weather stripping around all exterior doors and the door up to the attic. We had fiberglass insulation blown under the floor boards of the attic. Our attic has a walled room in the center and we had fiberglass bats installed on the outside of the walls and ceiling of this room.

We've talked about and researched insulation in the walls, but haven't moved forward for a couple of reasons. First, my husband wants to makes sure he's done running all the electrical and wiring while the wall cavities are empty. Balloon framing is great from this aspect. Second is the moisture issue. We've done a lot of reading and can't come up with a definitive answer that we're comfortable with. We do not have the wall cavities blocked where they enter the attic. I just asked him about this, and he says he's concerned about the trade-off between reducing ventilation and stopping air flow. Our exterior walls are cold to the touch, but the rooms are still pretty comfortable.

When we had the attic insulated two years ago, we did a lot of reading about fiberglass vs. cellulose. Decided against cellulose because of its ability to hold moisture (i.e. roof leaks) and because it's more flammable. We definitely notice a comfort difference with the fiberglass insulation. I can't tell you that it was the "correct" decision, but it was our decision. And I can't tell you for sure whether the insulation saved us money, because we had an addition built right after we insulated the attic. Our heating bills did not go up after the addition though, so I think the energy savings from the insulation must have offset the cost of heating the new space.

Our house is still chilly. We wish we had radiators instead of forced hot air. Heavy curtains on windows also help. We keep the thermostat at 68 in the day and 64 at night. I can tell you though, that it's a whole lot better than it used to be.

Wavy -
the infrared camera showed plenty of cracks and crevices that were black. And all wall sockets were dark black. The auditor actually said that insulating the wall sockets makes "a hill of beans" difference, which I understood to mean it won't make much difference.

He's absofrickinglutely wrong. Every black spot and line on that scan is a hole where money is leaking out. Whether it's cost-effective to plug the hole is what you need to consider.

Because hot air rises, start with the basement and make sure you don't have tunnels where cold air can move up through the walls and leak into the house.

Caulk the drafty basement windows and cover them with a temporary "storm window". Bubble wrap attached to the frames with double-sided carpet tape works real well and doesn't block light.

Caulk openings around pipes and wiring runs, or stuff pieces of fiberglass batts into them and then a chunk of foam cut to fit if they are too large to caulk. Insulate the walls with high-R foam to keep the cold ground from sucking the heat out through the walls.

Basement ducts insulation is controversial. From a thermodynamics approach, the heat lost to the basement shouldn't affect the heat balance of the house, but if you aren't using the basement, you might prefer to have as much heat as possible delivered to the main floors. Leave this until after you finish weatherproofing the rest of the place.

*********
Then, go after the drafts! You will be more comfortable at a given temperature if you aren't feeling cold drafts.

Caulk around ALL the baseboards, doors and windows, even the interior wall baseboards and trim. A tiny gap between wall and window frame adds up to a BIG hole in your wall.

Remove the outlet and switch covers, pull out the plug or switch body, then caulk the gap between the power box and the wall, caulk the gap between the wires and the box, and put a chunk of duct tape over any unused openings in the box. Don't just caulk around the plate cover - it's hell to remove for painting and useless for stopping drafts.

NOTE: This will also do a lot for pest-proofing.

wavy glass and arlosmom: Once upon a time mineral wool, aka rock wool, was a popular insulation material. It may be making a comeback. It has about the same R value as cellulose and fiberglass (But less than the foams). It's naturally non-flammable without the need for chemical treatment, will not absorb water or support mold and is all but impervious to mice, insects, etc. It comes in batts, but also can be blown in. I'm not sure how the cost compares or how available it is in different areas of the country, but it's worth checking on.

Another inexpensive way to increase comfort is homemade removable interior storm windows. You can find excellent directions for making them at: http://www.midcoastgreencollaborative.org. They are not at all difficult to make,if somewhat time consuming, and can be reused year after year. They can make a huge difference with leaky windows.

Thanks to mainegrower, arlosmom, and lazygardens for those last remarks. I find that I learn something new and useful with just about every 15 seconds of reading on this forum.

I am getting to the computer now at 7:50am after being awake in bed with my handheld internet device since 3:30am trying to think through solutions to my issues (right now I'm as irked about comfort as I am about efficiency).

Mainegrower's warnings about dense-packed cellulose and arlosmom's and lazygardens's great tips about what they have done are, actually, welcome bookends on a restless night.

Here's where last night's ruminations have left me ( I'm just tossing this out there for your thoughts):

The goal is to curb the stack effect created (in good measure) by our balloon construction and uninsulated walls. Part of this comes from stopping up areas of infiltration and cold temps below the first floor in the basement, and I plan to insulate the sills in the basement and perhaps add insulation to the basement walls. But the place to start, from what I understand, is at the top.

The issue with this is that one's options for stopping air flowing into the attic is that two types of standard insulation have drawbacks. Dense-packed cellulose has issues with moisture retention and threatens future issues with mold and rot. Fiberglass is better on those problems, but is not effective at stopping air flow.

So how about this approach:
(1) Take up the fiberglass that is currently on the unfinished attic's floor. (Remember, there is some old fiberglass blown in under the floor--not sure what, if anything, to do with that.)

(2) Save fiberglass.

(3)Have a layer (how thick?) of *open cell* foam sprayed on top of the attic floor, sealing bypasses next to no-longer-used chimney and utility vent pipes, and--importantly--sealing the tops of the second floor wall cavities that open into the attic.

(4) Blow the fiberglass back on top of the foam for added insulation.

Now, as I understand it, open cell foam acts as a decent air flow retardant, while allowing moisture to pass through it. My hope would be that a layer on top of the attic floor could be just the thing to curb the stack effect while allowing moisture to escape to be vented out the attic.

Mainegrower, last night's reading turned up a post of yours where you said: "Foam products may have a place - although who knows what their long term performance will be like - in new construction, but I'd avoid them in an old house." But this was coming right after you asked, "As far as any foam insulation product is concerned, what happens when you need to make additions or repairs to plumbing or wiring within the walls or ceiling?" Do the following facts change your mind about my case?:

1. Our house was completely rewired in August. All K&T was replaced.

2. I'm not considering putting foam into the walls. I would just put it on the attic floor, thus sealing the tops of the second-floor wall cavities.

3. I would only use open cell foam in a vented attic (currently ridge vents+cracked gable windows), reducing moisture issues caused by closed cell foam and nonvented attics (so I would *NOT* be doing this: http://www.oldmanstreet.com/blog/?p=118 [scroll down for pictures], even though that is basically what our attic *would* look like if the the current fiberglass were removed, although we don't have HVAC duct work in the attic.)

So what do you think? A measure worth considering?

Thanks again for all your great thoughts!

Moist air moving through gaps in the interior carries a lot more risk for water damage/condensation on cold surfaces than does water vapor migrating through old lath/plaster wall finish, especially if said walls already have 5-10 layers of paint. Stopping the air movement will pay off in many ways.
My house (balloon framed/braced frame) has blown-in rock wool. The installers even attached a "builder's plate" to the attic door attesting to the fact that it has "Johns-Manville Blown-in Rock Wool Home Insulation" with a brief manual on how it keeps the building comfortable in summer and winter. Wait, didn't Johns-Manville also make asbestos? OMG!
Casey

sombreuil_mongrel, if you wouldn't mind, could you tell me a bit more about why you decided to go with rock wool? Is that what you have in the attic, as well? Were you considering other options and if so what didn't you like about those others?

I ask all this because before I was thinking I'd get through this winter, but now I think it's worth doing ASAP. But I also want to get things right, so I can use all the help I can get!

thanks again.

We're still exploring options for insulating our walls and mainegrower's comments about rockwool make it sound like a great option. But I just now googled rockwool, and the first hit I looked at says the following:

"While it is not attractive to rodents, rockwool can pose problems in other ways, especially if allowed to become wet. Rockwool insulation is able to retain a large amount of water, although gravity will make it slowly drain out, as long as it has a way to escape. This ability to hold water, coupled with the fact that it retains a certain amount of air at all times, has made rockwool a popular growing medium in horticulture and hydroponics. These properties of rockwool allow for good root growth and nutrient uptake. It also provides a good mechanical structure for the plant, keeping it strong and stable."

When we researched options for the attic, the lack of a clear-cut winner of an option was frustrating. I'll certainly do more reading about rockwool, but this first bit of info was concerning.

By the three-digit telephone number that the installer put on that signature plate, I think the insulation was put in around the late 40's/ early 50's. This house was converted to a duplex in 1947. I would love to see an infrared scan of this building; or maybe I wouldn't...
I have stopped a lot of drafts, mainly at the baseboard/floor seam. I have also rebuilt and weatherstripped the windows, and as needed re-caulked the sides and tops of the storms.
I've gone through many cans of foam. Every little bit helps, especially the window work. Wooden venetian blinds and drapes make a huge difference too.
Casey

Casey, what is your attic insulation situation? Is rock wool blown in there, too, or do you just have rock wool in the walls and something else in the rest of the attic?

wavy glass: I was referring to wall insulation when I mentioned the difficulty of making repairs or additions. Your plan for the attic may be worth doing, but I'm not sure the foam itself is necessary. The problem with fiberglass is that it does not block air infiltration - air passes right through it; that's why old fiberglass insulation looks so dirty. If you could enclose the existing insulation with rigid insulation board or perhaps even plastic sheet, I think you would at least get the full insulation value of the fiberglass. I certainly don't claim to be an insulation expert, so be sure to check this idea with someone more knowlegable.

Arlosmom: I saw the same warning about rock wool and moisture as you did. The comment is technically correct, but completely misleading. Rock wool will get wet just as gravel will if its rained on. Neither the gravel nor the rock wool will, however, absorb and hold the moisture. That's really the whole advantage of rock wool over cellulose - which is hygroscopic - and, to a lesser, degree fiberglass. The rook wool used by hydroponic growers is similar to (perhaps the same as except in form)the insulation, but doesnt absorb water, either. The rock wool's purpose in hydoponic growing is to provide an anchor for plant roots with plenty of spaces for oxygen that will not degrade or compact over time. Anything that actually absorbs water and nutrients would be useless for hydroponic agriculture. The very qualities that make rockwool a good insulator - water shedding, easy to sterilze, insect and pathogen resistance, high ratio of air to solids - are precisely the qualities hydroponic growers need. My confidence in the website which gave the negative view of rock wool is, at this point, pretty minimal

Thanks mainegrower, will do.

I'm liking the idea of rock wool for at least the second floor walls which can be blown-in from the attic above.

One reason that I'm now being drawn to the foam is that we'd hopefully be able to pull up the attic floor and put foam down under it just to a depth where we could get the floor back on without having to build a new floor. Then if we wanted more insulation, I could ideally roll out batts on top of the floor. At least then we could regain some use of the attic for storage, right? I assume that while putting boxes, etc. on fiberglass insulation is not ideal, it wouldn't wholly compromise the insulation of the attic in the way that putting boxes on blown-in fiberglass would. With the foam acting as both air-seal and insulator, the extra batts could still help even if somethings are stored on top of them. Right now we have no use of the attic. So doing something that can help the house energy/comfort-wise that can also give us extra usable space is attractive.

The following, cheaper variant occurs to me: take up attic floor; seal areas of air leakage with canned foam insulation; use rockwool in second floor wall cavities;cap cavities using canned foam; blow in or roll out batts of rockwool under floor; replace floor; use fiberglass or rockwool batts ontop of floor.

If, when the attic floor is pulled up, I can significantly cut down on air leakage using foam sealant around air chases and rockwool in walls capped by foam at top of stud bay openings, there may be no real need for expensive foam on the entire floor, as mainegrower was suggesting.

Have we found a winner?! :)

I think you've got it. You can do a lot of the work yourself.
You asked what my attic was insulated with; it's the same rockwool, in the 8" deep joist bays.
Casey

Thanks, Casey.

If you recall, the auditor said that doing anything other than the walls--and by this I think he meant *all* the walls--would be pretty much useless. And even if I can blow rock wool into the open stud bays along the gable walls, this will still leave a good amount of the interior gable walls empty, as I presume the rock wool can't get, say, beneath the windows and such.

Yet it's my hope that putting *something* in the walls, and then sealing all openings in the attic will curb the stack effect. Or will the stack effect now just re-direct currents to the outside of the house through the tops of the first floor walls, instead of into the attic and out the attic as is the case now?

mainegrower's originally said:

"Adding insulation to the walls of a previously uninsulated house is one of the easiest ways to waste a good deal of money and do real damage. Blown in insulation settles quickly and loses its effectiveness rapidly. Without a vapor barrier on the interior, moisture will enter the wall cavity, condense and cause rot."

But mainegrower also was the one who first mentioned rock wool, saying "it will not absorb water." The DOE also says that "All loose-fill insulations are permeable to water vapor....fiberglass and rock wool absorb about 1 percent of their weight."

So is there an issue with putting rock wool into the second floor walls, or is there not an issue? Does the matter come down to whether I use an open cell or closed cell foam to cap off the stud bays? Open cell would allow moisture into the attic to be vented; closed cell would not. But of course, so much of what I read says keep moisture out of the attic.

Please help me get oriented on this last piece of the puzzle....

New tack: after talking it over with my builder father, and hearing his stories about houses like mine that he has to tear the walls out of because of moisture problems with cellulose that was blown into the walls, the choice is now between rock wool and fiberglass into the walls, and I may just go whole hog and blow into all exterior walls. Dad was convinced that rock wool was associated with asbestos. I told him that my research said that was (no longer) the case. He said that if it's still in use, it surely has severed its ties with asbestos.

wavy glass: a couple more thoughts:

One of your photos showed that there is already insulation under the attic floor. Assuming the attic floor joists are at least 2x6, you have insulation in place with a minimum R value 16 or so (3.2 per inch of depth). If you were to add a double layer of 2" tongue and groove styrofoam right on top of the floor, you will have achieved a total R value of 36. Not ideal for your climate, but not too bad either. The pluses of doing this:
No foam. It's incredibly sticky stuff, would be very hard to put down a uniform layer, and it's a pretty irrevocable step - removing it is probably not an option for you or anyone in the future.
No taking up floor boards which is difficult and usually results in damaging most of the boards.
If you put down plywood or boards on top of the styrofoam (and some other types of insulation board), they can be walked on and used for storage.
There are styrofoam panels made in special widths to fit between roof rafters which helps to make this an easy do it yourself job.

Minuses:
Cost.
A huge amount of left over fiberglass.
You'll have to check caefully to see how the soffits, etc. need to be vented in your house.
There's still no vapor barrier (I assume) between the the 2nd floor ceiling and the insulation.

Settling of blown in wall insulation is always an issue and balloon framing makes it worse. Thats not a reason not to do it, put I'd almost consider using some sort of removable cap on the stud bays in the attic so the wall insulation could be topped up every once and a while.

The kind of damage your father described is not at all uncommon. The worst I've ever seen was in a mid 19th century house. Owners had insulation blown in, then put vinyl siding on. Several years later, new owners stripped off the vinyl to find the bottom 2-4' of all exterior walls - clapboards, sills, boarding boards - totally saturated and rotted. Fiberglass insulation in this case.

Wow, so even blown fiberglass presents this significant risk of future rot, huh? As I say, I hate being cold and, secondarily, spending more in heating costs than necessary, but I'd hate even more to invite this kind of rot. Boy, all this is so confusing. But what's most confusing is how how "professionals" in this area can get away with pushing cellulose. Do they just have the "it'll be someone else's problem" mentality?

The second issue is settling. If I blow fiberglass into the walls, I will certainly ensure that the caps are removable. Thanks for the recommendation. But, if R value decreases or is eliminated with compression, does settling itself decrease R value? Would topping up in that case be a good idea, or not?

I will look into the styrofoam option. I believe there are no soffit vents, and no possibility of them. So that won't be a problem, at least from the standpoint of putting down the styrofoam. Not sure how much that'd cost, but it's the sort of job I could see myself doing in the spring or summer. I'd certainly get a company to come take the current blown fiberglass away, but that of course adds extra costs.

I don't want to be misleading, either. In the house case I mentioned, the poorly vented vinyl siding was probably the chief culprit along with a very water permiable interior finish. The fiberglass became saturated, but did not really cause the problems.

I'm not sure what total effect settling has on R value, but preventing big voids by adding insulation from time to time should tend to equal things out. That's pure speculation on my part, though.

BTW: My own house has no wall insulation. Main section was built around 1810, ell sometime in the 1850's. This is not a particularly old house for the area. Wood framed buildings can and do last for 100's of years because the builders used high quality, naturally rot resistant wood and understood the importance of allowing a house to "breathe". In mine, framing consists of corner posts and "studs" only to frame window openings, so these can vary from 2 to almost 4 feet apart. Blowing in insulation was never a practical option. Attic is insulated wth sheet styrofoam on the floor.

I hate being cold, too. For the last 30+ years, my solution has been a big wood stove and 6-7 cords of wood. Last year's oil usage was 63 gallons. The entire house is not toasty warm when the temperature gets low, but it makes a huge difference to have the large central living room at 85+ degrees with that wonderful blast of radiant heat.

thanks, mainegrower. boy, I'd say that I'd buy you a beer when we're in midcoast maine to visit the fam next summer, but my wife would think that's mighty strange and would probably forbid it. (She's the boss. :)

Perhaps you'd like a $20 gift certificate to your favorite restaurant up there. That I could do.

I've got the two most reputable insulation companies coming to give estimates tomorrow and the next day. The second guy is said to be a really knowledgeable expert, on both insulation and ventilation (one really should really go with the other, no?).

I'll report back on Wednesday night with how those go.

Until then, stay warm y'all.

Thanks again.

P.S., I'm glad you manage to stay somewhat warm with a fireplace. But after reading about fires in balloon framed houses, I gotta say that I'm pretty glad they walled off the fireplace(s) long ago.

?Think of it this way. Imagine you have three windows and your front door open, and you tell an energy auditor, "I want to improve the efficiency, but I'm not interested in closing the windows or the door."

I'd be at a loss for words, too!

Think of it this way. You read and read and read the forums, and are told time and time again that there are things that can be done before having to turn to the walls. Then the auditor tells you the walls need to be done. Then the auditor tells you you should cut a hole in the plenum of your furnace and have a register put in to heat your basement. Then the auditor tells you you don't have to worry about sealing up the cold air returns in the basement. Then the auditor tells you not to worry about letting water seep out from between your windows and storm windows. Then your auditor tries to sell you on insulating the walls, not because that'll prevent ice dams and strain on the furnace, but because new buyers love to see "Energy Upgrades!" on the spec sheet for a house on the market. Then the auditor recommends dense-pack cellulose which can trap moisture and rot your walls. Then you show the auditor areas of extraordinary air flow out of a kitchen wall. Instead of saying, Let's find the source of that!, he says, blow insulation in there!

Would you be happy with or trust the auditor?

Yeah! Pictures!
Starting with picture 1
not mice holes at one time some electrical lines or plumbing lines ran through this area
pic 2 caulk sill once air infiltration is stopped
insulate this would apply to all sill plates
pic 3
remove batt insulation seal around each line. these are
hvac lines and power they should be caulked where the penetrate the building envelope
pic 4
on attic side of door install foam sheating board
1" or two layres of 1" liquid nail and button cap nails to hold in place. this will add insulation to the door
door should also be weatherstripped and have a sill that stops air infiltration
pic 5
I'd add a second 2" of foam sheathing to stop air movement down the starcase. take a razor knife to custom fit the sheating to fit tightly and weatherstrip
this allows a huge amount of air to come down the staircase.this top of staircase hatch would stop the bulk
and the secondary air leak stop point would be the door.
it may also benefit you to caulk the stairs to the walls and wood joints of stairs.
pic 6
this is the one I found most interesting..your insulation beneath the floor is not in contact with the flooring
(and it will be better in some places and worse in others)
this creates a cold (this time of year) air pocket above the insulation. air movement through this pocket keeps insulation below from performing and de-rates the R-value.
on top of this is approx 2" of wood at R1 per inch. so you have insulation..air movenent area effecting the insulation in the ceiling joist and then 2" of R-2 as opposed to R-4 per inch. this is a thermal break in the insulation made worse by void in insulation below.
pic 7
yep..voids..insulation not in full contact with flooring of attic
pic 8
ok..gap at bottom..vented attic..unvented? I agree to install missing section..and weatherstrip it keep that air from moving across the insulation..windows in attics will condensate although there are similar temps on each side
pic 9 ditto
pic 10
nice install..that it is over floored attic is the only issue I have with it.
(how much of attic is floored and would you pick up the flooring above insulation??)
also...dig some of that insulation out from around that fireplace..bet the insulation will be dirty from the air leakage between the brick and attic flooring..an indication of air leakage..the other end of the leakage would be felt inside where the chimney enters the conditioned space creating a chase for the attic air to enter the house.. caulking will solve the interior leakage
it may take fire rated caulk or foam from inside the attic
althoug sometimes I use ductboard and fire rated caulk.
you have to be careful what materials you put in contact with the brick. ductboard has a fire rating.
pic11
that same foam board that you are going to custom fit to make a hatch to open before entering this space should be used to make sides of a 'box' for this hatch to sit into
once insulation issues are resolved cut foam board to seal from framing to flooring caulk and air seal and cut the foam board sides of this box to create a damn to hold the blown insulation in place. you can use foam board (easy to work with) or build the box with a 1x caulking to air seal.
pic 12
oh well..push it back he/she was checking the depth
and yes it is virtually useless in the floored area
(see above for why)
pic 13
yep..like the fireplace both are leakage areas
pic 14 & 15
ah...balloon framing..this is attic opening..under floor would be the other air chase that your walls are comprised of.
pic 16
how big are those gaps? you can purchase backer rods to put
in gaps larger than 1/4". put backer rod into gap and caulk both sides of backer rods to air seal. then install trim piece over this and caulk trim in place.

this like the fireplace interior sealing is the secondary leakage entry. my question would be..where is the primary leakage.

___________________________________________________________
ok here is my disclaimer....
first this is an online opinion
second..I'm in Louisiana..minimal cold weather experience
(well except for the below freezing week this year and the snow last year>>)
Also..in my area we have no basements..

_______________________________________________________
I don't think you got as much info as you could have gotten from your auditor. but for $375 including a IR scan..you got a good price.

I would have hoped that he/she would have show you more leakage sites with suggestions on sealing..but for the cost..like me I am sure that more would have been charged for a more detailed report. Wish we could see the IR images!

We have a LOT of balloon framed homes here. mostly older homes where balloon framing helped in the summer with cooling.

Our solution for homes on piers is to foam insulate the floor (lots of leakage in floors..plumbing penetrations..those 6"x6" bath drain holes..electrical penetrations) foam will seal most openings under 8".
The foam would also be used to seal balloon framed walls.
this would be your most cost effective (vs time and materials of diy) to achieve this.

What you have going on in your walls is a convective current where walls are heated on one side and cold on the other. stopping the air movemnent caused by no sole or top plate will be a huge benefit.
air at rest is a better insulator that moving air. not as good as fg, cellulose, rockwool or foam..but if you are looking for cost effectiveness...stop the air movement,

As far as the attic goes..
at the very least..I would diy moving the insulation back from all the exterior walls and foam sealing the tops of the open framed walls. the foam should seal this area to the attic flooring (so move that insulation back about 2' to allow for this) and the foam should cover the wall openings and seal to the roof deck.
then the issue of the wood and air space becomes LESS of an issue as the bulk of the air movement would be stopped.

now you would get into the issue of closed cell vs open cell.
see location disclaimer..
we use open cell here as it allows any moisture to dissapate. it isn't a question for me..because I've learned it is not if it leaks..but when it leaks..

once you stop the convective current in the walls you would need to get caulk..cases.
caulk floor moldings at bottom to floor and top to walls
caulk ceiling moldings at top to ceilings and bottoms to walls.
and around cabinets in kitchen and baths..look for spiderwebs as an indication of air leakage sites.
window frames to walls aprons to sills
door frames to walls.
this will help to catch the rest of the wall leakage not addressed with foam insulation.

basement issues...not going there!

this is all based on my experiences and how we address
similar issues in my area.

hopes this helps & best of luck

Our first winter in our old house was brutal, too. We now have the walls of the back half of the house insulated. Tremendous difference. I have been hot at night for the last few nights--without the electric mattress pad and down comforter we bought our first year.

Other things we did:

*New front door frame and weatherstripped front door. No drafts now.

* Door sweeps on all other outside doors

* Insulated switch and outlet plates with foam gaskets

* Caulked

* Wrapped all the heating pipes (we have steam) in the basement

* Rolled out fiberglass batts of R-30 insulation over the existing blown-in insulation in the attic

Big savings on our heating bill.

Have you looked at blown-in foam? I think TOH did it for their East Boston project.

I didn't realize it until we insulated, but the first few years I was too cold to be "at home" in our house. It's not a good feeling when you can't get comfortable in your own house. Forget about cost-effectiveness--your own personal well-being is worth something!

Wow, thanks energy_rater_la. Can't thank you enough for your suggestions.

I still have to look through your recommendations more carefully. For now, I wonder if you'd answer three follow-up questions?

1. What do you think of mainegrower's suggested possibility, which is to get rid of the fiberglass that's on the floor, and use some form of tongue and groove styrofoam boards on top of floor? I would fit these well right up to the walls of the attic, thus sealing off the open stud bays? After all, you say the fiberglass is virtually useless on top of the floor. Would styrofoam be as well? I could always eventually roll batts out on top of the fiberglass. Or do you suggest covering stud bays only with canned open cell foam, so that moisture can escape from the wall cavity? I could always lay styrofoam up to edge of stud bays, and then close the bays with open cell foam.

2. What do you think of these solutions for the basement sills: http://is.gd/69Mrz, http://is.gd/69MuL

3. What kind of caulk is to be used on all the "caulk here, caulk there, caulk everywhere!" recommendations? Even though I dont have the IR pics, and even though the auditor did not make the identification of leakage points a priority, I do know that the switch/outlet plates were solid black, and that lots of areas around baseboard and ceiling trip were black. So I think some caulking is in order.

The auditor has to come back before I can submit my states rebate claims, and he has to do the blower door test again to rate changes in houses tightness. So, even if not much has changed, Ill use that opportunity to acquire IR pictures of further leakage points. (Auditor confirmed that his IR camera takes pics, he just didn't take any while he was here. Why? I don't know). POs also installed French doors and a new porch that attaches to house on the other side wall that the kitchen cabinets are on. I will look all around there for culprit primary leakage point that could be contributing to the secondary leakage out of side of cabinets. He won't come back until next winter, after I've had time to do stuff and once it gets cold again. But hopefully I'll get your attention with another post featuring those new pics. :)

Finally, thanks for bucking me up. Thanks to all of you for that.

in that last post, in the first question, I meant to say that once the styrofoam is down, I could elect to roll batts on top of it for more insulation.

1. What do you think of mainegrower's suggested possibility, which is to get rid of the fiberglass that's on the floor, and use some form of tongue and groove styrofoam boards on top of floor?

with the air space under the flooring and air still moving from the wall cavities you are just wasting time and material by not addressing the air issues

I would fit these well right up to the walls of the attic, thus sealing off the open stud bays?

you would do better to use the foam board to seal the tops of each wall cavity..labor intensive, small area to work in.
even with the relative ease of foam boards..razor knife
button cap nails and caulk, you won't accomplish as good of a seal as with foam. and if you do..you will have inversted a lot of time and materials..foam is the easiest way to do this.

After all, you say the fiberglass is virtually useless on top of the floor. Would styrofoam be as well?
yes still air movemnent and insulation voids under flooring

I could always eventually roll batts out on top of the fiberglass. Or do you suggest covering stud bays only with canned open cell foam, so that moisture can escape from the wall cavity?

not cans..hire a company to do both top (attic) walls
and bottom of walls you could also use them for sealing the sill area.
although you could look into foam froth packs online and price a diy foam..cans will run you lots of $$ and the only open cell foam I know of in sm cans is great stuff in the blue can for windows and doors..your looking at $5 per can easily.

I could always lay styrofoam up to edge of stud bays, and then close the bays with open cell foam.

I don't follow...

2. What do you think of these solutions for the basement sills: http://is.gd/69Mrz, http://is.gd/69MuL

basements are not my area, but I think that the foam would both insulate and seal or you could caulk and use conventional insulation.
you keep getting into which insulation is better, when they
all will perform if air is not moving thru the insulation.
foam is a one step caulking and then insulating is two steps. how much time do you have?
I can afford to 'try things out' because I can test with my blower door and learn what works and what doesn't.
You are paying for the testing. big difference.
sometimes its a good thing to learn from other's mistakes
and experiences.

3. What kind of caulk is to be used on all the "caulk here, caulk there, caulk everywhere!" recommendations?

I use Alex brand 50 year caulk...and I buy all clear caulk
cause tubes get mixed up. water based goes on white dries clear cleans up..stickey but cleans up.

Even though I dont have the IR pics, and even though the auditor did not make the identification of leakage points a priority, I do know that the switch/outlet plates were solid black, and that lots of areas around baseboard and ceiling trip were black. So I think some caulking is in order.

folks really worry about those recepticle covers!
I know a guy that charges $5 per cover to caulk and gasket.
biggest waste of time I've ever seen.
Although in areas with high winds there is more of a benefit that in my climate. but its easy and cheap...knock yourself out. just won't make a whole lot of difference in the infiltration readings.

and btw..thats not 3 questions...LOL!

Hi, Wavy Glass

It seems that no one has asked if you would ever want to USE your attic as a room or for storage. Our house was built in '38 and has an attic that looked similar to yours after I tore out the ceiling tiles and rock wool. The difference was that ours has "kneehole walls."

If you have the time, you can do this yourself. I did ours a few years ago, when I was "only" 59. If you want to use the room, you will need to insulate the ceiling. Install air channels (you can buy them - not expensive) and then put up batts or rigid foam. Then add drywall. That part we hired out, just because it's a pain to haul it up the stairs. But with that window in the attic, it would be a shame to not use it as a room.

BTW, our house does not have a balloon frame. It seems that during the depression, they used whatever they could get. Ours is brick, brick, then plaster. No framing. So our walls are COLD. We keep the thermostat low, but insulating the attic and the basement, plus new windows and doors, really helps. The basement is finished and is now the most comfortable part of the house.

Good luck with the estimates tomorrow.

Ok,..as I'm in my usual hurry, I haven't read ALL the posts so if this conflicts with any you will have to weigh that.Here's my 2 cents.

I DO like cellulose,..it prevents many bugs and saved one of my buildings from burning down (also said by the state fire marshal) Superhot fire in the attic caused by an electrical mistake was so hot that copper wire melted.Huge beams too. (blast furnace effect because we hadn't done walls at that time and the races allowed this effect) However only 2 inches of the 15 inches of the cellulose burned off

You can stop it from settling by adding 10% of blowing in fiberglass when doing it,..
You can generally stop moisture by a good moisture barrier paint on the inside of exterior walls.

OK,.here is an old post of mine from a Landlord board so parts might not totally apply.

************************************************************
Here are a few more considerations. Yes if you can afford to do your units with a good color thermal camera and have someone come and do properties with a blower door, it would be better but you can come pretty close to finding out a lot about your property without them.

We still have half the heating season to go,..and they seem to come around again pretty fast esp if you are paying for heat.

I find that tenants appreciate units that are not energy inefficient and EZer to heat,and a selling point tp prospective tenants these days.

Go to my picture page and see pics of the way we add another layer of "glass" (plexi) to windows.The upper sashes,if they can't easily be accessed from the outside, we fit them in by holding them in with spaces made from foam 1/2 inch weather striping and then further holding them in with Daps clear Alex Plus. (so that you can still raise the windows up) We also add "pulls to the bottom sashes so that you have someplace to lift up same,.. A thermometer left on the still measuring the cold air falling from these windows are very close to new Anderson,Harvey etc window temps.

You will also see examples of what missing insulation looks like from the steam test.

The colder areas of the walls have moisture condensed on them and show up darker.

Here's the old post:

Ways to reduce heat loss in homes/apartments. First find the air leaks in your house. Air infiltration is a major source of heat loss, often surpassing the effect of good insulation.

First of all consider there is an inner and an outer seal of the envelope in your house. Both of these are important to seal. Note: despite what some people will tell you, it is extremely hard to get an older house too tight. Most that think they have done so have been shown to fail miserably upon testing.

To find the inner leaks you can place a HIGH capacity fan (about 50-60 dollars at HD ) in a window blowing air OUT, best place is a hall window on a first floor but any window will do. Make sure its secure (bungees, whatever) and then put polyethylene over it, secure that with either tape or staples. Cut out an area very slightly smaller than the cage of the fan.

At this time make sure the furnace is shut off and fireplaces are long out and flues tightly shut. Turn off any fueled hot water heaters. If you can, plug the exhausts of these with fiberglass insulation and make a big note to unplug them before you turn them on later! If you cant, you can still run the test pretty well. In furnaces you can usually do this by stuffing the fiberglass in the barometric damper toward the chimney.

Now turn on the fan set on high. If its set up on the first story, go outside and feel the air leaving your house. SOMEWHERE its coming in just as fast! This amount of air comes pretty close to the amount of air that presses in your house and comes in on a cold day! Your job is to find out WHERE. Have a friend open a window in the house. Can you feel much of a difference if they open/close the window? Probably not very much.

Now go back inside and close all interior doors that connect to the rooms that the fan is pulling from. That is, if its in a common hall, all the rooms that branch out from the hall. The whole house is connected in some way, think how the air flows to the fan. Now crack open one door at a time. Feel the air coming out of that room. Note which has most of the air coming out. Go back to that room and feel around, the windows, the base moldings, electrical outlets, etc. find out where its coming in and fix them with appropriate caulks, insulative ropes, Weather stripping. Check that room/door again. When you feel a lot less air coming out of that door go to the next room.

After you get the rooms done be sure to check the basement. This is very important. Often people will say they dont have a leaky house because they do the check for cold drafts on a cold windy day thing. This isnt really a good test because of the cold air pressure on a house causes a "chimney effect" That is, air coming in from the lower floors, will push out the air of the upper ones. That pressure is substantial so the warm air will always go OUT. You wont feel cold coming IN from those areas but cold air IS coming in from micro and not so micro cracks in the lower levels and pushes a lot of hot air outside! Like pushing an inverted glass down in water, the fact that the glass doesnt let any air out, no water can go IN. You try to seal the top floors leaks that you NOW can find because of the fan to causing a vacuum. Now after this is all done, Go outside again and feel the amount of air coming out of your house again. Do the open and closed window thing again. There should now be a difference. You might still have a lot of air coming out, remember that it still is coming in somewhere. Can you see if you can find any more?

Now it would be good if you can do the outer envelope test. To do this see if you can get a theatrical smoker , this gives off a LOT of non toxic "smoke" They are real cheap from Walmarts at Halloween. It also comes with a optional switch that will keep it going w/o having being in the room pushing the button each time its ready for the next cycle. Now you do the same fan thing but have it blowing IN. Start the smoke. You might call the fire dept to let them know you are doing a smoke test in case someone sees smoke leaving your building and calls them. Turn on the fan and go out, maybe with a video cam and note where the smoke is coming out. This is the outer envelope you should try to seal. Once you do this, with good caulk its should be a one time thing. It will pay you year after year.

Another way is a "poor mans" infrared test. Its an easy way to point out weak/no areas of insulation. Let temp in unit go down to around 60 degrees. On a very cold day, all you need to do is to boil water on all the stove burners. Add hot tap water as needed. It make take an hour or two. Use a few fans on high to circulate the air in the unit. You will find that the coldest surfaces will have moisture condense on them. In a while you will see windows condense first. Note which condense first,. Use a non flash camera to take pictures as you may not remember exactly where later and it limits the time you have to boil the water. After the windows,. generally parts of the exterior walls will get wet. Once in a while you might see an exterior wall condense. If so you may have a race in the wall open or a connection to a poor top seal in the attic. The pattern is very similar to what you may see on an infrared scan costing (in this area) hundred s of dollars.

Ok,.I'm in Western Ma have have some buildings in the mountains which is pretty cold (about 7,000 Heating degree days/season.) I haven't yet seen the moisture collected in walls that contain cellulose mentioned before, (when we are doing upgrades renovations and we have to cut into exterior walls.) Again,perhaps its because we make sure all our walls have vapor barrier paint on the inside of exterior walls.

I would say that NOT having SOMETHING in your walls with balloon walls is risky in case of fires. Again it almost acts like air injection to a fire. We just had a 180 year old church that had balloon framing w/o insulation burn up so fast that it shocked veteran firefighters.
I know as a landlord we pay more for insurance if the walls are uninsulated are empty. (Not always apparent when you get your insurance quotes/rates)
Perhaps you are paying for NOT having your walls insulated in other ways (?)

BTW we do it ourselves, depending on the building from the outside or from the inside (inside messy so we wait until the build/unit is empty)
We rent the blower and its pretty cheap with a couple of guys we hire. You can do a lot in one day,..

What did you end up doing and how did it go? I am in a similar situation and find all of the differing opinions/advice found online can be verrrry confusing. Would love to know how you faired!

What did you end up doing and how did it go? I am in a similar situation and find all of the differing opinions/advice found online can be verrrry confusing. Would love to know how you faired!