# Attic insulation. Cost and decision?



## freddypd (Dec 13, 2012)

I started following Velvetfoots discussion here and didn't want to hijack his thread too much so I started a new one. Here is Velvetfoots discussion on spray foam in an attic:
https://www.hearth.com/talk/threads/spray-foam-under-roof-decking.100006/

I am interested in becoming more energy efficient and wanted to add insulation to my attic. I had a contractor come over and he does all types of insulation but I can tell he is very partial to spray foam. He did say my application was great for spray foam because I have a ranch with an incredible amount of recessed lighting. He said the higher cost of spray foam would be offset by the labor charges on a traditional attic insulation (air sealing, building a plywood walkway, and air sealing my recessed lighting)

His quote was:
$6600 spray foam roof 5" open cell
$1020 spay ignition barrior over attic spray foam
$1180 3" spay foam basement rim joists
$200 air seal in attic
$250 duct sealing
$175 repair some attic ductwork insulation

$7133 after local rebates.

Now my yearly electric is approx $2200
my yearly oil bill (prior to wood insert install)$3200
for a total of approx $5400. Even if he saved me 10% (which I think is high) that would be $540/year for a 13 year payoff. Am I doing that right? If I am that is totally not worth it. Especially considering that I should be using MUCH LESS oil than prior years since we now burn 24/7 in the living areas of the house. I would rather put that money towards a new 2 zone central A/C and possibly extra insulation done by me?


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## Highbeam (Dec 13, 2012)

Foam has some superior applications but attics aren't one of them. I have a very hard time believing that this job wouldn't be much cheaper with blown in FG or cellullose. Even if you must air seal your can lights first.

Building a plywood walkway? What is this guy, some sort of special needs insulator? in this business you need to be able to crawl around on the framing.


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## Tramontana (Dec 13, 2012)

+1 on Highbeam's comments.

I had an estimate to add to the existing 12" shredded fiberglass insulation, over-blowing with cellulose to reach R-45 which was less then $900 for 1200 s.f.. I haven't yet proceeded only because I have a little more work to complete in the attic prior to pulling the trigger.

Also, cellulose has been shown to act as an infiltration (air) barrier, so air sealing isn't necessary. However, I will likely crawl through and use fire rated spray foam to seal wiring and piping penetrations myself, but I'm sort of a belt and suspenders person anyhow.

Lastly, cellulose is treated with a borate salt, and doesn't support a flame, so fire proofing is unnecessary.

I will recommend air sealing/insulating the floor joists with spray foam. Perfect application.

Cheers!


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## sesmith (Dec 13, 2012)

I'd start by having an energy audit done.  NYSERDA is still doing free/reduced energy audits, if you qualify by income:

http://www.nyserda.ny.gov/Residenti...novations/Comprehensive-Home-Assessments.aspx

Regardless, a good energy audit can give you a good idea how much you might save by beefing up the insulation and air sealing.

Maybe get a 2nd estimate from an insulation contractor who likes cellulose??

You could save a lot by doing the project yourself.  I did my rim joists using 2" XPS cut into pieces and sealed with spray foam in a can.  Pretty cheap to do as a DIY project.  Depending on your access, sealing can lights and blowing cellulose in can be no big deal and relatively inexpensive.


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## Highbeam (Dec 13, 2012)

Be careful, not all can lights are rated to be air sealed or insulated against. You could have a fire.

My cans are I/C rated and airtight so I had no qualms about goobering them up with regular caulk until I was satisfied that they would be sealed as well as the rest of the ceiling. Before insulation I went through several tubes of caulk for every ceiling pentration and top plate pentration.

Oh and I didn't build a plywood catwalk!


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## maple1 (Dec 13, 2012)

I'm confused by the catwalk too.

Did he mean you'd save by not having to build a catwalk with using foam that you would have to build with using 'traditional' insulation?


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## laynes69 (Dec 13, 2012)

Our old Victorian was very drafty. Our attic was approx. 1200 square feet. We airsealed, ventilated, and insulated with cellulose for under 600.00. It made an instant difference. Our home isn't typical framing (mansard roof) so I got creative with venting. In the end, the upstairs of our home was 10+ degrees warmer, drafts were reduced and the house stays much warmer in the winter and cooler in the summer. We choose cellulose due to it ability to resist air infiltration (still airseal) and it's ability to maintain it's r-value. Where we had storage in our attic, I built up the area with framing and used fiberglass batts. I couldn't see the expense of foam. It took my wife and I about 2 hours, we blew in about 52 bales.


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## velvetfoot (Dec 13, 2012)

When we got a bunch more fiberglass blown in we got three estimates and they were wildly divergent.


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## Jack Straw (Dec 13, 2012)

I would see how much you save with the wood burning before I made a large investment. My stove heats my house so well I really don't care about increasing the insulation in the attic. I burn less than 75 gallons a year and that's with heating my garage.


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## woodgeek (Dec 13, 2012)

Um.  Airsealing my house saved me ~35% of my heating load.  With your recessed, it could be even higher.  Are you 100% wood now, scrounge or CSD?


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## laynes69 (Dec 13, 2012)

Jack Straw said:


> I would see how much you save with the wood burning before I made a large investment. My stove heats my house so well I really don't care about increasing the insulation in the attic. I burn less than 75 gallons a year and that's with heating my garage.



There's more to it than just heating. But reducing the heat load, reduces wood consumption and increases comfort. A drafty home that's not up to par with insulation can still be uncomfortable no matter the temp. Also increasing insulation makes a big difference in the summer months with cooling. Pumping more wood and heat into a home is just a band-aid and not adressing the real issues.


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## Jack Straw (Dec 13, 2012)

laynes69 said:


> There's more to it than just heating. But reducing the heat load, reduces wood consumption and increases comfort. A drafty home that's not up to par with insulation can still be uncomfortable no matter the temp. Also increasing insulation makes a big difference in the summer months with cooling. Pumping more wood and heat into a home is just a band-aid and not adressing the real issues.


 
I just think more research needs to be done before 7k$ is spent......


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## laynes69 (Dec 13, 2012)

Jack Straw said:


> I just think more research needs to be done before 7k$ is spent......



I agree. There's ways to be effective and economical when it comes to energy upgrades.


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## jharkin (Dec 13, 2012)

Another vote for cellulose... You can rent a blower and DIY for very little money. Note that in loose fill it slows air infiltration but doesn't stop it completely like dense pack.

If you have old can lights, build a box around them to seal, or rip them out and replace. I did like highbeam, ripped all mine out, installed new airtight IC cans, caulked them airtight. And updated to led to boot. Once you do that the cans can be buried in insulation.

I'd reccomend reading the Harley book on insulation before you make any decisions.
http://www.amazon.com/Insulate-Weatherize-Tauntons-Build-Like/dp/1561585548


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## midwestcoast (Dec 13, 2012)

Yep, I don't think I'd be paying that kind of money to have an attic foamed. In an attic you typically have lots of room to pile on the insulation and you have access to seal air leaks beforehand so foam looses some of it's big advantages (air barrier & high R-Value per inch). I put cellulose in mine for a few hundred bucks after MUCH time air sealing up there. My place is a Cape Cod so I had much more air sealing to do than usual.
It is a pretty straightforward DIY job. Just do some reading about where & how to air seal & insulate and learn how to deal with your specific situation (like building little boxes over your can lights or replacing them...). Take your time & seal it all up right, then blow in enough cellulose that you'll never consider adding more. On blowing day you'll need a helper to feed the hopper.  
Take the $5-6 Grand you saved & get your AC unit or whatever else


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## freddypd (Dec 14, 2012)

Highbeam said:


> Foam has some superior applications but attics aren't one of them. I have a very hard time believing that this job wouldn't be much cheaper with blown in FG or cellullose. Even if you must air seal your can lights first.
> 
> Building a plywood walkway? What is this guy, some sort of special needs insulator? in this business you need to be able to crawl around on the framing.


 
Thanks for all the replies.

That's funny. He meant that contractors that do blown in insulation build plywood walkways in the attic with sides so that you can still walk around up there to service the A/C or in case you need to run wires etc..


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## freddypd (Dec 14, 2012)

sesmith said:


> I'd start by having an energy audit done. NYSERDA is still doing free/reduced energy audits, if you qualify by income:
> 
> http://www.nyserda.ny.gov/Residenti...novations/Comprehensive-Home-Assessments.aspx
> 
> ...


 
I did about 1/2 of the rim joists in the basement myself already. He said he would overspray those and complete the areas I have not done yet.


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## freddypd (Dec 14, 2012)

Highbeam said:


> Be careful, not all can lights are rated to be air sealed or insulated against. You could have a fire.
> 
> My cans are I/C rated and airtight so I had no qualms about goobering them up with regular caulk until I was satisfied that they would be sealed as well as the rest of the ceiling. Before insulation I went through several tubes of caulk for every ceiling pentration and top plate pentration.
> 
> Oh and I didn't build a plywood catwalk!


 
My cans are all air tight and IC, so I guess I am one step ahead.

I thought I would have to build boxes or buy pre made ones like these to air seal the lights:

Recessed light covers

I guess some of you just caulk them as is or spray foam them?


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## freddypd (Dec 14, 2012)

woodgeek said:


> Um. Airsealing my house saved me ~35% of my heating load. With your recessed, it could be even higher. Are you 100% wood now, scrounge or CSD?


 
It seems some of you are saying blown in cellulose negates the need for air sealing? Air sealing seems to be a very tedious but very important job.

This is my first year burning. So I would say year 1 we paid for 4 cords.

I have been scrounging so that might be end of year 2 into year 3. I may still have to buy wood for the beginning of year 2 if the scrounged stuff is not dry enoiugh. I am still learning what works and what doesn't.


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## Tramontana (Dec 14, 2012)

My wife and I have been (slowly) remodeling our 2400 sf home since shortly after moving in 5 years ago. House was built in 1961, and while it was built soundly, it was not well insulated. The main floor had no insulation in the walls, and probably an average R-24 (at best) in the attic.

Realize that energy was relatively cheap in '61 and insulation cost money, and air sealing wasn't even a consideration.

We gutted the walkout basement down to studs and joists and started fresh. Applied UGL drylok paint to all of the foundation walls, then glued up 2" extruded polystyrene insulation board, then framed up full 2x4 walls and insulated with net & blow cellulose. I then foamed the joint around every floor joist & rim joist and tucked a section of R-19 double faced batt into each cavity. We then had the exterior walls on the main floor drilled and blown full with cellulose.

Next will be adding blown cellulose over the top of the existing shredded fiberglas to reach R-45 in the attic, once I'm finished with a little more electrical work.

Last december we replaced our open fireplace with a new Jotul Oslo, but we are not yet full time burners, as I don't yet have room for enough wood. Next year... Wood shed! 

Cheers!


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## Tramontana (Dec 14, 2012)

Others have mentioned energy audits, and I agree that they are a good tool for establishing a baseline for your home, and can give good recommendations as to areas of your home that need work and/or attention.  Some companies even offer follow up audits once improvements have been made, and this can help quantify improvements.

Having a blower door test performed will establish how many natural air changes your home experiences (ie, how leaky it is) and should help to identify obvious points of ingress/egress of your tempered air.  Also, if they offer it, having IR thermal imaging performed during the blower door test can help to identify problems with existing insulation and or missing insulation in addition to focusing on air leakage.

Good luck with your improvements.

Cheers!


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## GaryGary (Dec 14, 2012)

Hi,
I'd put another vote in for DIY cellulose.
We bought the cellulose at Home D and used their blower. Cost next to nothing and only took a few (dirty) hours.

I did do air sealing first, and I think this is important.
Got all the wiring and plumbing penetrations and every other hole I could find with Great Stuff,

I suppose some may think this is not a good way to go, but I sealed the can lights with alum tape from the inside and used a bit of Great Stuff where they meet the sheetrock on the top side. All of these cans now have very low wattage CFL or LED lights and just don't generate much heat. I logged the temperature inside one of the cans for several days, and the temperature remained way below any level that would cause concern. Then, I just piled the cellulose over the cans with no boxes.
You'll have to make your own assessment of whether that's safe enough for you.
Here is another way that I like -- nice light: http://www.builditsolar.com/Projects/Conservation/CanLEDRetrofit/CanLEDRetrofit.htm

I put in a couple of minimal walkways because the insulation is now well above the top of the ceiling joists -- wish I had done the walkways larger, longer and more carefully, but they are OK.

You can estimate the dollar savings using this calculator: http://www.builditsolar.com/References/Calculators/InsulUpgrd/InsulUpgrade.htm
For us, the payback before the state of MT rebate was 2 years -- basically nothing with the rebate.

Have to say that $7K to insulate an attic is a bit shocking.

-- If you want a good book on this stuff, the Harley book Insulate and Weatherize is very good -- very hands on.


Gary


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## Highbeam (Dec 14, 2012)

GaryGary said:


> All of these cans now have very low wattage CFL or LED lights and just don't generate much heat. I logged the temperature inside one of the cans for several days, and the temperature remained way below any level that would cause concern. Then, I just piled the cellulose over the cans with no boxes.


 
The problem with this approach is that somebody may install a high wattage incandescent bulb in there someday and burn the house down due to your mistake. Children could die in their sleep, or maybe wake up before they die. Not cool. Use the proper IC rated can.


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## maple1 (Dec 14, 2012)

freddypd said:


> Thanks for all the replies.
> 
> That's funny. He meant that contractors that do blown in insulation build plywood walkways in the attic with sides so that you can still walk around up there to service the A/C or in case you need to run wires etc..


 
So now I'm wondering if you can walk around on the foam? I think that would be the only way he could say you need a walkway for blown in but not foam - and I don't think I'd try walking on foam knowing there's only sheetrock under it in places stopping me from going through a ceiling.


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## GaryGary (Dec 14, 2012)

Highbeam said:


> The problem with this approach is that somebody may install a high wattage incandescent bulb in there someday and burn the house down due to your mistake. Children could die in their sleep, or maybe wake up before they die. Not cool. Use the proper IC rated can.


 

Hi,
As I said its a decision people have to make for themselves, but the risk seems low to me even in the case you mention.
Its a metal can installed in sheetrock and covered with fire treated cellulose that you can't get burning with a propane torch.
Gary


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## kingquad (Dec 15, 2012)

Tramontana said:


> +1 on Highbeam's comments.
> 
> I had an estimate to add to the existing 12" shredded fiberglass insulation, over-blowing with cellulose to reach R-45 which was less then $900 for 1200 s.f.. I haven't yet proceeded only because I have a little more work to complete in the attic prior to pulling the trigger.
> 
> ...


Unless you're talking about dense pack cellulose, that is not true.  It's not as bad as fiberglass, but it doesn't act as an air barrier.


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## kingquad (Dec 15, 2012)

There's a lot of good free info about this all over the web. The Finehomebuilding site is a good place to start. I'll also second the recommendation for the Bruce Harley book. I think every home owner should have a copy, even if you're not a DIY'er.  Lots of very good info in there.  Just make sure you get the second edition.


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## Tramontana (Dec 15, 2012)

Technically you are correct, cellulose is not an air barrier, but it does slow air movement.

From the Greenbuildingadvisor;

Because of the fiber characteristics and high density of blown cellulose insulation (3 to 3.5 pcf compared to mineral wool or fiberglass batts at less than 1 pcf), it is very effective at preventing internal convection and has been recognized as an effective fire-stop by third-party testing and code officials. While it may not meet the strict requirements for an air barrier material (0.02 l/sec-m2 or 0.004 cfm/sf @75Pa), it will significantly enhance the air-resistance of an assembly over other fibrous cavity insulations, maintain its rated R-value by preventing internal convection and dramatically reduce the flammability of a building structure.


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## johnny1720 (Dec 17, 2012)

I bought the atticat stuff from home depot, fluffy pink fiberglass blown in stuff. I paid about a grand to get 32 of the bags and a buddy helped me install it. It took two hours. I had a quote for 3k to spray foam my kitchen walls so I didnt even get a quote on the attic. I wished I could step back in time and get another quote on the foam. I could have bought the DIY spray foam kit and done my kitchen for $600 then put fiberglass over it. The atticat stuff is great but the foam is superior in so many ways.


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## Shane N (Dec 19, 2012)

Why did they quote you for open cell foam? I don't see any reason to use that instead of closed cell.


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