Keep Old Foil Fiberglass Insulation?
barshfield
| Posted in Energy, Heating & Insulation on
I bought a house that was built in 1960. Two bedrooms get noticably colder than the rest of the house in winter. The house has 2×4 outside walls with foil-faced fiberglass insulation batts in most, but not all areas. I’m considering taking the interior walls “down to the studs” if it would be beneficial to replace the insulation and get a good seal, while at the same time upgrading the electrical work and filling any uninsulated bays (I have found some, and suspect there may be more). (I’ve also got some HVAC issues, and I am addressing them separately.)
Do any of you think I should keep the old insulation or, for the sake of keeping the drywall hung, just work with what I’ve got?
Thanks, Mark
Replies
The old foil stuff varied alot. It can be between 7-13 R value, though it's not marked and I can't tell you how to tell the difference. Some people say that it's about the same R value per inch as modern insulation, but I tend to think the new stuff is better.
The foil on the insulation is actually a really nice ting providing a radiant barrier effect similar to Tek-Shield and other modern products.
Another thing to remember is you want to check your paint for lead before you remove the drywall. You can get a lead test kit from any major paint store for a couple bucks. If you do have lead I the paint you can take a certification course at most paint stores that will tell you how to properly dispose of the drywall.
Depending on how your electrical system that alone might be worth doing it.
Not sure I gave you an answer, but I hope it helps.
If you are talking about the RRP certification............
"If you do have lead I the paint you can take a certification course at most paint stores that will tell you how to properly dispose of the drywall."
then it deals mostly with the approved removal techniques and proceedures leading up to that. While the course and certification are required of anyone professionally involved in reno on pre '78 homes, there are to date no requirements for home owners.
I would however urge the homeowner to at least go to the EPA site and study up on the regulations and techniques if he intends on demo'ing.
I'm in the midst of a similar remodel of a 1957 house. Same exact issues.
At this point, 'half-measures' make no sense at all.
Here's what I'm doing:
First, strip off the old drywall. A multi-master type tool is ideal; it may be slow, but it really keeps the dust to a minimum. Still, you want a vacuum with filters, etc., designed for drywall dust. Mine - a 10gal contractor-grade Shop-Vac with HEPA filter and a HEPA toss-away bag liner - cost about $125.
RRP? My interior tested clean of lead paint. Since I'm doing my own work, RRP rules don't apply, anyway.
Opening the walls, I found paper-backed rockwool. Problem is, the insulation was -at most- 2" thick in the middle; along the studs it was maybe an inch thick. No wonder the place is hard to heat. Behind the insulation I found solid board sheathing.
Now, with everything open, is a good time to check for hidden mold or insect damage. So far, my place is fine.
A fair amount of grit had found its' way into the rockwool, and the vapor barrier was as delicate as wet toilet paper. Don't try to save it; just rip it out. There's not enough insulation left in it to be worth anything.
I plan to spray the inside of the stud bays with a fire-resistant coating (think of a real thick paint), then insulate with a fire-retardant spray foam. Cost should be about $1500 for 40 lineal feet of eight-foot high wall, filled 3" thick. You really want some sort of fire barrier between the foam and the wood sheathing; that's what the coating is for. The coating will also seal the cavities - as if the foam won't seal it as well! The foam is its' own vapor barrier.
Of course, before you foam you'll want to re-do the electrical. The old stuff doesn't have a ground wire. Indeed, it is the wiring that made opening the walls necessary in the first place.
Besides the lack of a ground wire, you'll find the electrical code has changed quite a bit since the house was built. You'll need many more circuits, and many of the circuits will have to be dedicated to certain uses. You'll want more receptacles than you had, and you'll want them in different places.
Whether for drilling the studs or driving screws, nothing matches one of those little pistol-size impact drivers.
Let's put this all in perspective: Right now, the house requires about 33,000 btu of air conditioning on a hot summer day. When I finish with the remodel, I expect that requirement to be less than 20,000 btu. I expect my winter heating bill to be half of what last winter cost me - and it was a mild winter.
What you said goes against alot of what I understand about foam
renosteinke wrote:
I plan to spray the inside of the stud bays with a fire-resistant coating (think of a real thick paint), then insulate with a fire-retardant spray foam. Cost should be about $1500 for 40 lineal feet of eight-foot high wall, filled 3" thick. You really want some sort of fire barrier between the foam and the wood sheathing; that's what the coating is for. The coating will also seal the cavities - as if the foam won't seal it as well! The foam is its' own vapor barrier.
OK, what you said goes against alot of what I understand about foam in that:
1. Assuming you are using closed cell, you want the foam to bond to the wood studs as well as the sheathing, as it will give you a more rigid structure.
2. You use foam precicely because it fills all those nooks and crannies as it expands
3. You fireproof the exposed surfaces of a foam installation (vent channels, underside of rood decks, rim joists), areas enclosed on all sides don't need it as they are already fireblocked in.
Thanks for sharing - soulds like you are taking it the next step!
Hey Mark,
Replacing the insulation could really make a difference, especially if there is such a noticeable temperature change between the rooms. Replacing dry wall can certainly be a hassle, but there is serious added value to the home (on top of heating and cooling costs) if you make the replacement now instead of holding off on the project. The R-value you can achieve with new products makes almost any change a good one and with a product like Owens Corning Energy Complete, there is further value added with an air tight seal and Green Approved technologies.
"JasperTommy", just out of
"JasperTommy", just out of curiosity, how much are you being paid to promote Owens Corning Energy Complete?
Hey, OC boy.
Add a signature line to the bottom of your posts stating that you are a rep from Ownes Corning, and contact information so you can be followed up with.
At the moment you are riding the line as to whether you are a spammer or not. You've been adding good information to your posts - which is good, but you aren't disclosing your crporate representation - which is bad.
It is not my intention to be a spammer, not in the least bit. I'm just trying to help folks with different questions. I also do digital work for Owens Corning.
We welcome expert industry input, but you have to disclose who you are. We've already had "digital work" done here by someone from Owens Corning, and it looks an awefull lot like spam.
That is spam. Why? ecause we don't know who you are or what your basis of expertise is. By not identifying yourself, you pretend to be me. You are not me, you are geting paid to post here. You have just inserted a simple advertisement into our forum, which is actually a form of theft since Owens Corning didn't pay Taunton Publishing for the right to advertise on it's forums.
Since you are apparently new to the internet, and need some guidence, here's a better way of giving the same the exact same post: