Photo 1

photo 2

photo 3

The insulation belongs on the top of the roof. Putting the insulation above new drywall on the inside will eventually rot out the roof and the insulation.

{{gwi:2136528}}

Here is a link that might be useful: Don't be Dense

Worthy, I'm not arguing, but trying to learn...

How does spray foam insulation on the bottom of a roof deck work, if insulation like in your above picture produces rot? (Why don't sprayed roof rafters also rot?)

I don't understand your pricing? It makes it seem like it would be worth it to keep the ceiling and do this from the outside?

what kind of shape is the roof in currently?

I'd have to price it both ways to make a
choice.
adding rigid foam sheathing to roof &
all the complications that brings
vs
using spray foam insulation inside the
ceiling joists & re-doing the ceiling.

condition/warranty/roof information would
factor in. as would having to walk the crews
through each install.

more info please.

In order to keep the ceiling and attain the insulation value, the best solution would be to strip the existing shingles and add new rafters on top of the plywood. You want to maintain positive bearing so you would need to install the new rafters directly over the existing rafters. Then you would add foam air baffles by stapling them to the plywood exterior. You would then add the new insulation in between the rafters, then new plywood and shingles. You would also need to demo the old fascia and gable trim/rake etc, in order to hide the new overlaid framing and integrate it, however, when you finish the gutter etc will hide most of the difference. You may also want to think about the gable end of the roof. If there is already an overhang, you may want to remove it then frame a new overhang using ladder framing to build a new overhang so that it will not be too thick, this depends on the thickness of the existing overhang and the size of your new framing, for instance, if they are both 2x12, it will look very odd having a 24" thick gable end. Typically you would not want the gable to be more than 12" thick. You can email me if you have any more questions. halebuilt6@gmail

If you add new rafters, you just perpetuate their thermal bridging. Uninterrupted foam board directly over the existing roof deck/sheathing,(to whatever thickness is required to reach the r-value) then 1x4 strapping horizontally 24" o.c. (fastened down through the rigid insulation into the rafters), then another row of strapping vertically (16" o.c.) for the new sheathing to nail to. This gives you a proper, vented cold roof with no thermal bridging.
Casey

granted replacing the roof can be done,
but a huge undertaking.
not knowing what kind of shape the existing roof
is in leaves a big piece of the equation blank.
then the issue of how to tie into existing roof
from this new roof has to be figured in also.

simpler & easier to use foam insulation
from the interior & recreate the 'look'
of the ceiling.

I find it hard to believe that the t&g boards
we see in the pics are the same wood that
the shingles (?) are nailed to.

if OP would post a picture of the outside of the
house & roof suggestions would be more
on track for decision making.

answer questions about roofing
& post pics of roof from outside OP?

Sorry for the delay in posting. You can be sure that the shingles are nailed directly into that T & G board you see in the pics. Those boards are a good 1.5 to 2' thick.
My roof is in medium shape right now. No need to replace it now, I need some flashing repaired around the chimney, but all in all a good roof.
That photo above is scary, the black insulation, but knowing my roofing boards are not rotting, they are almost 2" thick, I cannot see that happening.
I thought about the spray foam, I thought if I used regular insulation, if you wanted to, you could revert back to the current look.
I got 4 estimates. Major companies like Champion - they make their own insulated panels. Estimate was around 24k. A good roofing company said 15k. They would order panels from a dealer they work with. Lower priced roofers scared me, they would drop their price to just get the job, they would allow me to order the panels online. These panels come with 2 x 6's embedded into the panels with plywood attached to the top side. You screw through the wood into the roof beams. Then shingle over the plywood. These panels are heavy, you need a crane to do the job. I did not trust these guys could do this for the low 10-12k they were offering.
I've seen some nice photos of great rooms like this with the exposed Beams with sheetrock in between the beams. They must be insulated right. Back to that photo above with the rotted insulation, how do they do it.

Anyway, if it was your house, and you saw the electric bill - Nov - March will be around $3400 total - not to mention the $400 of firewood I burn - What would you do? . Yes, I have a good quality Wood Stove Insert in that chimney - first photo. Does a good job of heating that large room, but the electric meter still spins.

Thanks for the feedback.
Hef

What Casey said.

Anyway, if it was your house, and you saw the electric bill - What would you do

third time...
I'd foam the roofline & make a ceiling below.
no way I'd try to integrate new roof to old, unless
I could get up there & diy.
getting too old for those kind of diy jobs.

IF roofing was to be replaced then I'd consider
sips for the roof.

how about that outside pic of the roof?
still can't see from here.

Here is a pic sorry, you have to click the link - the roof on the right is over the great room - as it moves to the valley you are in the kitchen that has a normal insulated roof. On the other side the wood ceiling goes full length. The worst part about SIP panels on the outside is the changing of the roof line. It's major work, and could end up looking terrible.
I've been reading about Thermal Bridging, while I'm sure there is a decent amount of heat loss through those large beams, I'm thinking about the big picture. RIght now the heat goes up and out the ceiling, mostly I assume, where the beams are not, through the T&G. I would be insulating a very large percentage of the roof. I've also been reading about the rigid closed cell insulation board. I can get 48 x 96 x 2" ...would make for an easy installation.

Here is a link that might be useful: House Roof

Another vote for what Casey said.
Probably easier/cheaper/better to add on top and it preserves the look inside.
I wouldn't consider any other way.

this is the message I get when trying
to view your pics:
"The page you requested cannot be displayed right now. It may be temporarily unavailable, the link you clicked on may have expired, or you may not have permission to view this page."

"RIght now the heat goes up and out the ceiling, mostly I assume, where the beams are not, through the T&G."

heat loss is through the lack of insulation in the roof.
wood is a poor insulator with R-1 per inch.

not sure if you are talking about foam boards
on the roof, or between joist/rafter bays from
inside the roof.
please clarify & make pic available.

adding insulation/ sips panel/ foam sheathing boards
to top of roof will eliminate thermal bridging.
but all will require exterior construction.
then to flash & make construction water tight,
deck & shingle (?)

how much construction are you willing to
do at this point?

most destructive, but with best end results would be
to add insulation on top of roof.
tear off. build up/ insulate/re shingle (??)
have to keep it dry while all is going on.

less destructive, would be foam from inside
house, sprayed to t&g. then construction
of ceiling from interior of house.

more internal construction. thermal
bridging stays.

it depends on you to decide which route
to pursue.
when you've decided, post back.

just fyi see how this type roof is constructed.
attach your pic with in the text of the post as you
did for your earlier posts.

best of luck.

this is the best I've got at the moment -

Looking at that photo - to the right, above the front door is the main room. That ridge going across is approx 30 ft. Most of that roof is not insulated. the part over the kitchen - which is under that valley you see is insulated.
Doing this work on the outside would be best..I agree. But costs considered, it would take a long time to recoup that expense. I've priced those SIP panels, and if I could do the work myself, it would be great, but other than that it's a huge undertaking.
This pic was taken on a nice day in the early spring...cant wait. That's what this house was built for , those nice days.

a picture is worth a thousand words, kheflw.
thanks for making that available.

sips panels are expensive. what the others
are describing is foam sheathing in layers
on top of roof, with decking & shingles.
4-5" all finished. then flashing in valleys
change.
it can be a challenge for a homeowner
to hire a roofer who understands how to
do this type of roofing.
the next challenge is that the workers understand
the install.
anytime I've had a roof design that was different
from the norm I've wound up on the roof doing
the install with them. even though the roof contractor
"knew" how to do it. just my experience.

the pic of the rotted roof with batts tells me that the
installers didn't install the insulation correctly.
there has to be an air space between the top of
the insulation & the roof decking. otherwise
moisture forms & rots the roof deck as evidenced
in the pic.
maintain the air space & roof decking stays intact.

the least expensive for you would be the following.
install batts. depending upon the size of your
rafters you'd want a batt at least 1" less than
the size (depth) of the rafter.
staple flanges to faces of rafters. this will
leave the space between the batt & the t&g.

install the foam sheathing boards by nailing
to the faces of the rafters. tape all seams,
caulk foam board to perimeter of ceiling to walls
or rafter, depending on how it falls out.

you'll want the foam boards to fit tightly to
the walls & will need to cut around for fireplace.
caulk well as this is a critical air sealing detail.
after foam boards are installed, sheetrock.

then you can decide if you'll stay with a
sheetrock ceiling, or go back with cathedral
look. in any case the insulation will perform,
the foam board will stop air infiltration, the
sheetrock will also help with infiltration & is
a fire rated barrier between living space
& foam sheathing.

its a fairly detailed install. if you chose to do this,
you'll have to walk through with installers & do
your own quality control.

if you opt to use spray foam insulation you'd
forgo all but the sheetrock. I'd overfill the
rafter bays & shave the excess foam back personally...
but then we use open cell foam rather than the
closed cell foam that your climate may dictate.

best of luck.

energy rater,
With your method, does he have to have ventilation to the outside at the bottom and top of the air space between the t&g and the insulation?

I thought it was "ventilated air space" that prevented the rot in worthy's picture, not just "air space".

This post was edited by greg_2010 on Fri, Jan 30, 15 at 14:37

Greg, answer is it depends.

If Op's roof has ridge vents, then
ventilation would need to be added
at 'soffits'.

hard to tell from pic, but it does look
like ridge vent...

in theory the air space (1") is enough
to allow moisture to dissapate.
works in my climate & from what I read
it works in heating climates also.
but...the devil is in the details.

there are still details we don't know.
ridge venting?
size of joists/rafters?
which install the Op is consitering...

Thank you - those are ridge vents you see, but they serve no purpose, there is no ventilation through the ridge. Not sure why they are there.
So you are proposing that I cover up everything inside. I would never consider that, but thank you for the detailed explanation.
Over the summer I got all of those estimates for the outside work. Raising the roof line and panels above. I gave up due to the price. It's too much and too destructive.
What I proposed in this thread, was insulating in between the Rafters or Beams as I call them. It is approx 40" wide in each cavity. there are 16 of those cavities. That is over 1000 Sq Feet of uninsulated ceiling, with about 80 sq feet of Beam that would remain uninsulated.
So using the rigid 2" insulation or 3" if I could find it, with an air gap on top like you mention, I would leave a good 4" of Beam exposed. Then either sheet rock or use T&G to cover up the insulation in the cavity. With either of those, I would use a quarter round or other trim nailed to the beams to hide the edges.
Again, I really appreciate your help, please dont get me wrong, but I certainly have strong opinions on the interior look of my house. The photos do not tell the story, it's a great look, but i'm just tired of that electric bill. So it is either do nothing, or insulation in between with T&G covering it or sheetrock, with the beams remaining exposed.

so now you need to get costs of the 2-3" foam board.
quick rule of thumb is cost of materials, doubled
is labor. it will be a bit higher depending on details
but give you a ballpark cost.

there are different types of foam boards.
rigid foam which has a higher R-value
and flexible foam which has lower R-value.

its a lot of labor to cut to fit, attach & caulk to air seal
the foam boards.

thus the recommendation for closed cell
spray insulation. job would be done in one
day, for approximately the same cost as
the foam board & install, which would take
several days.

so price it both ways.
get a couple of foam insulation bids,
then foam board, caulk bids.
be sure to add labor costs for the latter.

depending on size of beams, you'd decide
upon how many inches of foam & how much
is left exposed after new ceiling is installed.
1/2" sheetrock then thin t&g boards nailed
back in place.

with either foam board, you'll need a fire rated
material, which would be the sheetrock. then
the finished ceiling material.

you'd retain the look, insulate & air seal,
which will lower utility costs & improve comfort.

I'm sure you are concerned with the look, but
you did ask for options. this would be the
least invasive.

whatever you chose is going to have costs,
the only cost you know for sure now is the
utility costs.
get the rest of the numbers so you can make
an informed choice.

best of luck.

For the work I quoted. I'm confident I can do this myself. It's all fairly light materials. I can rent a scaffold.
If I use 3 in Rigid Foam. Would I put it directly on the current T&G? Or should I leave an Air Gap between? Preferrably directly on the face of the T&G.
Thinking of different methods to attach foam- I can use screws with washers directly to the current T&G. Or how about spray glue? I'm not a big fan of that. Cutting it does not sound difficult. Cut it outside to that 40"
Sealing it is tough- Would you recommend that foil tape, expanding foam, or a lot of caulking material?
Are you saying use Sheetrock plus T&G on the bottom? Why both. Why not just T&G or Sheetrock. Is it because of the fire resistance?

Thank you

can you share a link of the product you are
going to use?
the type of foam board matters, as does
the size of your beams. what size beams?

yes, sheetrock is for fire rating. gotta have it.
T&G is for your aesthetics.

I'd install it tightly to the ceiling & eliminate any
air gap. unvented roof assembly.

the foam boards should be measured to fit
tightly.
I find that cutting all the pieces at once can be
the wrong thing to do as the space
may vary.you want the insulation as
continuous as possilbe & sealed air tight.
each section caulked into place.
all gaps between foam board & rafters
well caulked. caulk will shrink as it dries,
so making a second pass the next day
will seal all gaps.
I like clear caulk that goes on white, but
dries clear. any gaps or missed spots show
up well on the next day.

you won't often see me recommend duct
tape, but using a decent duct tape like
gorilla duct tape to seal pieces together.
not to the beams, just foam board to foam
board. you can caulk these seams too..

I use roofing nails. big flat head.
you can also use construction adhesive
on the T&G and between layers of foam boards.
(dunno what size beam or foam board?)

then the sheetrock, screwed through the foam
& into t&g.

different types of foam
Expanded Polystyrene (EPS) lowest R-value R-4

Extruded Polystyrene (XPS) medium R-value R-5

Polyisocyanurate highest R-value R-6

the latter is the best choice.

questions?

So the Polyiso looks good and easily available - Home Depot $30.47 for 2' x 4' x 8' http://www.homedepot.com/p/Rmax-Thermasheath-3-2-in-x-4-ft-x-8-ft-R-13-1-Polyiso-Rigid-Foam-Insulation-Board-613010/100573703

Also, Sears - about $40 for 2.5 x 4 x 8

Home Depot looks good to me.

Starting to get serious now. It's cold in here.

Here is a link that might be useful: Home Depot Link

This post was edited by kheflw on Fri, Feb 6, 15 at 21:21

The reason I suggested what I did was that I actually built one of those roof systems way back in 1989, and was pretty satisfied with how it turned out. I was all supplied in the kit from a co. that fabricated timberframe structures. This was their system, and I think with some increase in thickness it would meet present-day R-factor code. It was very easy, exceptionally safe, 2 people could do it, and no crane required, and all the materials were easily found locally anyplace in the US.
By the looks of your roof, if we're talking about only the front ell part, you're really fortunate, because the extra thickness should not bring it above the main ridge line. If you're doing the entire house roof, then it doesn't matter.
Casey

it's been a while but the project is underway. I'd like to thank the group here for the great info thus far. What you see here is 2 layers of 2.5 inch thick Polyiso foam. I've got 1/2" sheet rock covering it. You are looking at 6 of the bays. Another 10 on the opposite side of the room. I'm going up to the height you see with that 10ft ladder. Will be renting a scaffold in a week or so. I've done everything so far by myself. Foam is light, press fit between the beams. Sheet rock is only 3ft by 4ft. Almost too much to handle on top of the ladder but I've made some nice things to help hold up one side. Might hire some help to finish the top. The T&G wood will finish the job. Trying to find a deal on 6 inch pine. Stained it should be fine. As you see I have a good 4 inches of beam left it should look good when done.

Yep, will still have that thermal bridging but I'm syched about the insulation possibility. I've already pointed my thermometer up there. Drastic difference between the old wood and the insulated part. Keep the heat in a cold out.

Thanks

Hef.

just a closeup to see the two layers of foam. Staggered seams. No air gap. Pressed right against the ceiling. I had to buy 6 inch drywall screws. There is no room for any varying thickness.

I realize the energy concerns, but I miss that T&G look. We always retrofit them from the exterior. Granted, most are calling us about a roof at the same time so that cost is fixed.