I wouldn't worry too much about the "r" numbers - it's just a guess, based on the measured depth, where it can be measured - the difference of 4 points is a nothingburger.

The difference from r-19 to r-49 is a big deal, an improvement you can feel in both comfort and utility savings.

Personally, in my area, blown cellulose is cheaper than fiberglass, and it performs slightly better than fiberglass for air infiltration.

I think you're on-track with your question about adding more - the biggest cost when blowing insulation is labor - and going from r34-r49 should only cost a few pennies a sq/ft. In my area, 10" of r-30 cellulose installed costs about $.40 sq/ft - I'd be surprised if R-35 cost more than $.50 a square foot(assuming your attic is accessible without heroic measures)

Thanks! I think I will have them add more. I just found out from one of the bidders that even tho' on the Energy Star website it states my zone is 5 and we should be at a R-49 he said our area has not implemented the new codes yet.

Bah! I'm going to have to have them redo the bids. Oh well.

I would have them search out air leaks and seal/foam them first where vents and wires and anything else comes up through the attic before adding more insulation. The air in the house needs to stay out of the attic and the attic air needs to stay out of the house. The insulation will help with this but not near as well as a few cans of foam and few cans of caulk.

Insulation does an awesome job of keeping the heat from radiating between two surfaces but a very poor job if air is moving through.

Totally agree with countryboy. Well sealed r-20 is probably better than leaky r-49.

You would probably want to move all the insulation to one half of the house. Foam. Move to the other 1/2 and repeat. I think I used 10 cans for 2000 sq feet. The big leaks are around bath fans and then flourescent lights. They just jam a wire through a 2x2 inch hole with no sealing - the typical round cutouts for lights leak much less.

Energy star is not the same as code. In my area, the attic insulation numbers are the same not everywhere. I think a lot of areas are r-38 code and r-49 for energy star.

This is sounding like more work and more work, but I hear you. I get the heebie jeebies thinking about going up in the attic and poking around that old insulation. I'd rather have someone else do it.

I'll go back to the bids and have them look for leaks. They would know what they're doing, right? I know some of you guys have special infra red cameras to look for leaks. I want to make sure they get everything.

One would think that sealing penetrations is standard. I just built an energy star house which required foaming around windows and door and making sure all fiberglass on walls was covered on 4 sides. That meant extra blocking especially on knee walls in attic and behind bathtubs.

I added a few other things but I'm not sure that one of the options was to seal the penetrations from ceiling into attic. I just did it myself - was easy without insulation there yet. No infrared camera needed as there was light whereever the holes were. In some cases, a lot of light. And that was just from windows, in a completed house, you could turn on lights at night and really see any leaks.

I also foamed around any penetration even if I didn't see light. Basically light fixtures (1 per room + closets), smoke detectors, HVAC vents, and bath fans. I had put some speakers in so I built boxes around them that were also foamed.

While on the subject, I built a box around the attic stairs and put a second lift off door with insulation and weather sealing. Costs I think most people around here would want to do their own just because then you know the job is done right. But I'd ask you insulation people. They might suggest just foaming for an inch everywhere - costs about $1 a sqft. Not a bad option and it doesn't require any thought or attention to detail. The foam has r-value of course and so you can cut back on the blown-in part (how much depends on foam but r-7 would be typical closed cell).

I disagree on sealing penetrations if the homeowner has to pay to get it done. In a perfect world, sure, seal them all when you're building the house, but for a retrofit, you can gain significant savings just by blowing in the insulation.

I know it works, I've done it myself on a couple of houses, without sealing penetrations, and my utility bills improved greatly.

It's all about maximum gain for minimum expense & hassle - pick up the dollar bills and leave the pennies if you have to.

It is worth the effort and no it isn't standard
for penetrations to be sealed before insulating.
blower door testing is one way to find leakage,
moving insulation around bath fans, stove vents,
recessed lights and sealing before adding more
insulation keeps attic air from entering the
living space. caulking is cheap, and benefits
are long term
looking for light from living space into attic,
and dirty insulation are leakage sites.
insulation particles enter the living space from
these areas along with extreme attic temps
and wreck havoc on iaq.

5 1/2 inches of insulation is R19. in my climate
we insulate to R 38. cheap upgrade. but seal holes
first.

there are products like attic tents seal attic stair cases
at a premium price. building a box and insulation the
stair case is anothe good upgrade.

best of luck,.

Kitty, If you just have someone seek out where the plumbing vent comes into the attic space and where recessed lights or other light fixtures are in the ceiling and have a look along with bathroom fans and seal them up will make a noticeable difference. If the holes you or they find are huge that will tell you that it is worthwhile to move all of the insulation and go after as many as possible. If who did the work only left small areas open around these items that might be a different story.

Throwing more insulation up there will make a good difference but nothing like some sealing beforehand will do. The dust level in the house is usually greatly reduced after even partially sealing up the attic.

If what is up there is blown in there are machines that you can rent to suck it up, do the sealing and then blow it back in place.

The infrared camera will give you some idea how leaky the areas around the lights are by just looking at them after they have been off for awhile and same goes for the bathroom fan. A small hole filled here and there will add up quicker than you think.

countryboymo,
walk her thru the ice chest install for recessed cans.
looking for dirty insulation will be an indication
of air leakage.
and check the duct takeoffs on central plenum.
dirty insultaion is no mastic seal (or failing seal)
+ unsealed return = higher utiltiy costs poor indoor
air quality.

seal holes and do all work in attic prior to adding insulation..am I repeating myself?

best of luck.

I would agree and say seal the leaks first. If it was mine, I would do this myself. The low paid insulation employee will not care about how well the job is done, especially since all of his work will soon be buried.

Hello I am looking at some HVAC options I have a 3000 SF ranch brick style home built in 1969 in Fort Worth Texas.
I do know that at some point I will need to up date my two systems. I will also need to seal and Insulate for leaks and all that comes along with the whole package I am open for any efficent recomdations and any advise would be greatly appreciated.Our home is total electric any advise will be greatly appreciated.
Thanks Mr. See