Insulation

[ECrew28]

Ok so I had a couple folks out to the house to give me an estimate on blowing in insulation.  The quotes, as well as the advice, was all over the place. 

So I wanted some advice and thoughts.  I live in the Chicago burbs in a house built in the early 70s.  There have been zero updates in terms of insulation in the attics (one over the upstairs and one over the familyroom/garage).  Windows were all replaced last year, as was the roof.  So I went in the attic as things are starting to get cold and was pretty shocked to not see hardly any insulation up there.  All 3 contractors said I was between R8-R12 in most places.  So Im losing a LOT of heat and AC.  So the advice I got was the following:

I need to remove all the existing rolled insulation as it has all deteriorated and flattened.  Then install new roll insulation with the paper on it, to provide a vapor barrier (doesn't sound right, but ok), and then blow in on top of that to about R49.  I have quotes that range from $700 to $3000 and I want to make sure I do the right thing.

But, I am also wondering how realistic this is to do entirely on my own.  We are going to be in this house for a LONG time (God willing) and I want to do this right.  Thoughts?   

[strider3700]

Blown in is messy but easy enough to do with 2 people.   Anywhere that sells the insulation will rent the blower and many places will give you a free rental if you buy enough bags. first step since you're staying a long time is ditch the old insulation if it's really that badly damaged.  Then go around and find every single hole through the ceiling and spray foam/caulk them tight,  you want zero air movement going up.   The old insulation will be dirty where the air was moving.   Next seal with a vapor barrier once again to stop air movement.  After that get the blower and go to town basically you need to make sure you're not blocking any venting at the soffit's.  They make foam pieces that you stable to the underside of the roof to make sure air can get out.    The bag's of insulation will tell you how deep to make it to meet the R-value you're aiming for.   This is real messy dusty work,  wear a good mask at the minimum.   One person stays outside and feeds bags of insulation into the hopper and the other is in the attic spraying.   

If you spray too much and block the venting then you run the risk of the roof rotting out after a few years.   Other then that getting things sealed tightly is the only difficult part and the better you do that the more effective it will be. 

I'd get some measurements and go to home depot or similar and price out the insulation to see what it's likely to cost materials wise.   They'll also have someone there that can make recommendations on how to do the vapor barrier for houses like you have.   

[velocistar237]

A Do-It-Yourself Guide To Sealing And Insulating With Energy Star, with pictures!

Building Science Corporation, We Need To Do It Different This Time, which discusses the need for air sealing when adding insulation. It doesn't mention a vapor barrier specifically, just air sealing (though they do have an entire vapor barrier topic category).

[thurston howell iv]

I know this is a DIY forum however, I thought I would suggest another alternative---- Spray foam insulation. I used to see this done in the big fancy houses in FL when I did some a/v stuff back some years ago. I contacted a local company about this and had it done to my house at the time. The stuff went on fast and made the basement like a igloo cooler. (In a good way) It basically sealed up everything and wasn't as expensive as I had imagined. There's also some tax benefits if I recall correctly.

This is the company I called (I have no affiliation or interest)  : http://www.epiphanyfoam.com/gallery.php
Just to give you an idea of what can be done...

I think it was much easier, less messy and probably cheaper in the long run...
Just a thought.

[TomTX]

Spray foam may also be able to go on the underside of your roof - which will reduce the heat leakage in your ducting.

[Alan2]

If by spay foam under the rafters you mean this sort of thing:

http://www.spray-insulation.co.uk/loft_insulation.htm

It can be a bad idea as it leads to rot in the roof timbers and other problems:

http://www.telegraph.co.uk/property/propertyadvice/jeffhowell/3359206/How-worthwhile-is-spray-insulation.html

http://www.spab.org.uk/advice/technical-qas/technical-qa-15-roof-maintenance/ (second Q & A down)

[TomTX]

Looks like the problem is specific to slate and tile roofing, and there may be a climate component.

Around here (Texas) there are a couple of differences - most roofing is composition 3-tab shingle, and the climate is notably warmer/drier than the UK.

Several high-end builders around here use spray-foam for the underside of the roof.

[Rufus T. Firefly]

Been researching attic insulation.  Some good YouTube videos.  Air sealing the attic is essential.  One video shows an attic filled w/ like 3 feet of blown in insulation only to have to moved to properly air seal.  Cold air will enter your living area even w/ rolled/blown or any combo if attic not sealed properly.  Insulation does not provide any type of air-tight seal.

[reverend]

I was going to mention spray foam insulation too. Imagine Homes (here in South Texas) uses it a lot with very good results. With near airtight homes, you need a heat recovery ventilator too.
To retrofit a home with sprayfoam in the attic, you might want to consider spray-foam sealing the FLOOR of the attic and not the rafters.
With a vented attic, you're really looking at preventing hot air from rising into the attic which causes mildew and stuff.
It's a concern here in South Texas where the humidity is so damn high all the time - sealing the floor of the attic allows the rafters to stay vented and mostly dry.

[Debbie M]

When I bought my house, I got it weatherized and they put in rolled insulation in most of the attic and blown insulation in the hard-to-reach corners.  Then when I replaced my central A/C, they just added more on top.  So that's interesting to me that they want to pull yours out and replace it.  Are they saying that because you need the air pockets for insulation?  Or is it so they can charge you more for more supplies and more labor?

One issue I worry more about lately is reversibility.  You often assume that your update is awesome and permanent, but I'm learning that sometimes even good ideas aren't as good as (or compatible with) some later ideas.  So I have a bias towards updates that are reversible.

I know fiberglass is a horror to mess with.  Blown-in insulation is generally made of something much nicer, though it could still get quite dusty.  But locking in your ducts with spray foam doesn't sound like a great idea to me.  And even if you're just doing the attic roof, I think this might make it harder to yank out if you later decided to make a higher roof (for more livable space inside) or a flatter roof (so it could be a green roof).

[TomTX]

When I bought my house, I got it weatherized and they put in rolled insulation in most of the attic and blown insulation in the hard-to-reach corners.  Then when I replaced my central A/C, they just added more on top.  So that's interesting to me that they want to pull yours out and replace it.  Are they saying that because you need the air pockets for insulation?  Or is it so they can charge you more for more supplies and more labor?

One issue I worry more about lately is reversibility.  You often assume that your update is awesome and permanent, but I'm learning that sometimes even good ideas aren't as good as (or compatible with) some later ideas.  So I have a bias towards updates that are reversible.

I know fiberglass is a horror to mess with.  Blown-in insulation is generally made of something much nicer, though it could still get quite dusty.  But locking in your ducts with spray foam doesn't sound like a great idea to me.  And even if you're just doing the attic roof, I think this might make it harder to yank out if you later decided to make a higher roof (for more livable space inside) or a flatter roof (so it could be a green roof).

Um, adjusting roof pitch isn't exactly cheap and easy - that's typically a very expensive, major renovation to a house. Getting out a utility knife and cutting ducts free from spray foam would be in the negligible cost category.

[Scizzler]

I'd highly recommend putting down an inch of spray foam over the entire attic before putting any other insulation on top of it. Air sealing is vitally important when insulating for greater energy efficiency, and from what I've read, most losses in heat are due to convective movement of air, not conductive transfer. I recently put an inch of spray foam down over my bedrooms and bathrooms, and it has made a noticeable difference from the rooms that don't have the spray foam over them.

Most of the cost of insulating your house is in labor, so if you're willing to DIY, you can save a lot of money- especially on spray foam. I was quoted $4.50 a board foot (1"/square foot) to have spray foam installed. I did it myself for about $1 a board foot. I ordered through this site, and had a great experience: http://www.sprayfoamdirect.com/

Check out the videos and let me know if you have any questions. I would have installed spray foam in my entire attic, but moving all the loose-fill cellulose was such an incredible hassle I'm not in a hurry to finish it. I am contemplating sealing the entire underside of my floor with spray foam though, as a less expensive alternative to encapsulating the crawlspace.

[Blindsquirrel]

 When the US gov had a tax credit, insulation was dirt cheap. Back half of house is now r90, front half is about r59 in attic. This cut propane use from 1100 gallons a winter to 400 gallons last year. (mild winter) Fiberglass rolls of r30 were $4.90 then. Best investment return ever. Know insulation is spendy now but type super energy efficient house into google and it will blow your mind. super insulated house in northern MN can go with no central heating and a couple of 1500 watt space heaters for the whole fricken house. 

[c]

I follow this blog as she has some great tutorials. She blogged about blow in insulation, which I'd never heard of before. It looks like theY did it themselves (but they are quite handy) http://ana-white.com/2012/12/momplex/heat-security

[TomTX]

I'd highly recommend putting down an inch of spray foam over the entire attic before putting any other insulation on top of it. Air sealing is vitally important when insulating for greater energy efficiency, and from what I've read, most losses in heat are due to convective movement of air, not conductive transfer. I recently put an inch of spray foam down over my bedrooms and bathrooms, and it has made a noticeable difference from the rooms that don't have the spray foam over them.

Most of the cost of insulating your house is in labor, so if you're willing to DIY, you can save a lot of money- especially on spray foam. I was quoted $4.50 a board foot (1"/square foot) to have spray foam installed. I did it myself for about $1 a board foot. I ordered through this site, and had a great experience: http://www.sprayfoamdirect.com/

Check out the videos and let me know if you have any questions. I would have installed spray foam in my entire attic, but moving all the loose-fill cellulose was such an incredible hassle I'm not in a hurry to finish it. I am contemplating sealing the entire underside of my floor with spray foam though, as a less expensive alternative to encapsulating the crawlspace.

It's the hassle of moving all the loose-fill insulation, plus the up-front cost which is concerning me for sprayfoam. Looks like around $2,400 to put down an inch of spray foam (stupid kneewalls add a fair amount of square footage.)

Of course, a lot of the perforations and crap insulation is in the kneewall, so I guess I could see about just sprayfoaming the kneewall. I'd just have to un-net and pull the squares of fiberglass.

------part of attic---|
                            |
Kneewall------>      |
                            |____other parts of attic____

[Scizzler]

I sprayfoamed some of the knee walls around my FROG (finished room over garage), and it wasn't too bad. I pulled the fiberglass down, sprayed an inch of foam, and stapled the fiberglass back up. Unfortunately, I can't get to most of the knee walls to finish the job, so that room will always be closer to whatever the attic temperature is than the rest of the house.

If you aren't going to spray foam the entire attic, at least take a day and air-seal it. For the areas I didn't cover in spray foam I've gone back with a couple of cans of spray foam sealant (great stuff and the like) and sealed off the ceiling fixtures, where the duct work penetrates the ceiling, and where electrical cables penetrate the top of interior walls. Basically, anywhere that air can circulate into the attic from the house below. It's still a hassle to move the loose-fill insulation back, but since you're doing small areas at a time it's pretty easily done by hand. It's definitely worth your time to air-seal before adding more insulation. Create a map of all the ceiling fixtures before you start, and once you get oriented to where everything in the attic is it goes pretty fast.

A good book on the subject is 'Insulate & Weatherize: For Energy Efficiency at Home (Taunton's Build Like a Pro)'. I have the 2002 edition and highly recommend it.

Finally, you might want to consider installing a radiant barrier when you're done insulating. I installed one in my attic last year, and the difference is astounding. Using my handy laser-thermometer, the underside of the foil (I stapled it to the underside of the roof) is typically 15-20 degrees cooler than the underside of the roof. It can also be a lot of work stapling the foil to the underside of the roof, but you can also just lay the barrier over the insulation. Besides air-sealing, the radiant barrier is probably the best bang for your buck. I got 3000 sq/ft from http://www.ecofoil.com/ for about $400 shipped, and I was quoted $3000 by a local heating/cooling company to have them install one. I'll be doing the same thing to my rental property to save wear and tear on the AC unit there as well.

[TomTX]

I'd like to do a radiant barrier, but the designer for our roof/attic was just insane. 1700sf house. ~44 "squares" of roofing material both times we have had it re-roofed due to hail damage. So... ~4,400 square feet of roof. It is incredibly tall - we could easily have a couple of rooms up there if they had put the HVAC off to one side. Plus all sorts of angles/interfaces/gables

My last house had a very simple, low roofline.

[Scizzler]

In that case, just lay the barrier over the insulation on the attic floor. You could also drape some over the ductwork as well. Although I stapled mine to the underside of the roof, I didn't go all the way to the peak of the roofline. Instead, I took the barrier up the roof about as far as I felt safe doing (with a step ladder), and then ran it across the other side, like this: 

 /____\
/          \

About half the total airspace in the attic is above the radiant barrier. I'll take some pictures this week and post them here to make it clearer.

[DK]

When the US gov had a tax credit, insulation was dirt cheap. Back half of house is now r90, front half is about r59 in attic. This cut propane use from 1100 gallons a winter to 400 gallons last year. (mild winter) Fiberglass rolls of r30 were $4.90 then. Best investment return ever. Know insulation is spendy now but type super energy efficient house into google and it will blow your mind. super insulated house in northern MN can go with no central heating and a couple of 1500 watt space heaters for the whole fricken house.

How much did you have originally in the attic? I kept going back and forth to put more blown in and finally didn't. I had read that once you get a certain amount, anything additional doesn't make that much of a difference. It's covering the rafters now, I think about 8-10inch are in it. I read the initial 3-4in make a huge difference, the next 6 make a difference, then the next 6 make a little difference, and so on...

If I could have blown in a bit more cut my usage in half I totally would have done it, especially with how much propane costs these days. Ugh.

[DK]

I'd also second (or third or fourth) what others have said that if you are clearing everything out, to go through and air seal any holes in your attic to keep air infiltration low and then insulate it.

If you're clearing everything out I'd say just load'r up with blown in cellulose to replace it to a high R value. I think if I had to start over again, I'd do what someone said and put down a inch or two of spray foam, and then do blow in cellulose over that. You can get one of those dow frothpaks to do it yourself if you don't want to hire it out. When I looked into adding to my attic, you can usually get a free rental of the 'blow in' machine with buying enough packages of cellulose.

[AlexK]

If you go the blow-in route be sure to use the pink fiberglass stuff (mine had a pink panther on it) over the grey cellulose. The pink fiberglass stuff is NOT itchy and it doesn't make dust. The cellulose stuff is extremely dusty and miserable to work with. It also settles sooner.

[Rollin]

I'd highly recommend putting down an inch of spray foam over the entire attic before putting any other insulation on top of it. Air sealing is vitally important when insulating for greater energy efficiency, and from what I've read, most losses in heat are due to convective movement of air, not conductive transfer. I recently put an inch of spray foam down over my bedrooms and bathrooms, and it has made a noticeable difference from the rooms that don't have the spray foam over them.

 I am contemplating sealing the entire underside of my floor with spray foam though, as a less expensive alternative to encapsulating the crawlspace.

Part of the advantage to spraying the underside of the roof vs. the floor of the ceiling is that your HVAC will be in "conditioned" space and operate much more efficiently.  Twice the life out of your system.  50% reduction in AC, 30% in heating.  Also, the roof has a 99% barrier to water intrusion and is 3 times stronger against wind lift than Miami-Dade standards (the toughest in the country).  This may not matter if you are not in a hurricane area, but it wouldn't hurt (tornados anyone?).

It ain't cheap though.  I'm staying put so I invested in it at $3 a square foot (2 inches thick).

[unplugged]

Over a decade ago we bought this house new and had a free energy audit. We received free things and free advice. One was to blow insulation in. They even reimbursed part of the costs! We just rented a blower and it was easy.

We are now hoping to insulate over our garage which is under our daughters room. The only way seems to be cutting holes and we don't want to do that.

[smalllife]

We put spray foam insulation in the attic, and will do so in the crawlspace as well.  It took a lot of digging and judgement calls about how much of which type (closed and open cell) to get, but in the end we did just open cell.  After pricing it out we let the contractors do the whole thing - cheaper than doing it ourselves as the space was so small the extra amount we would have to buy more than covered the labor.  It made a world of difference in the heating and air retention in the house.

[Rural]

We did spray foam on the roof deck in our new house, R40 or better everywhere, so about a foot thick. Since we were on new construction, we went with spray foam in the exterior framed wall, too. We're tight sealed, and the sound damping is really amazing. We're also staying warm even though there's no heating system yet.

[Spork]

We did the same.... the other really nice upside is that (with the foam at the roof line) the attic is inside the envelope.  Things that are stored there no longer have to go through extreme hot/cold and it is pleasant to do attic work.  There is also no awful itchy stuff and the mechanics, electrical, plumbing are all easily accessed.