Wall insulation renovation
James
walls and attic.
The house is a two story house built in the mid 70s, with brick
exterior on the bottom and aluminium siding on the upper floor. I'm in
the greater Toronto area, my heating source is all electric baseboard
and installing a furnace would be a major renovation since I have no
ductwork. Gas was not available on the street when the place was built
but has been for sometime. I have also considered bringing in gas to
put in a natural gas fireplace in the basement, and replacing the
electric water heater with a gas one.
The attic is straightforward and easy to do myself - the fibreglass
has settled and I need more.
The walls are another matter. I do think they were insulated at the
time of building with loose cellulose, but I think over the course of
30 years, it has settled and/or shrunk with moisture. I think I will
be in the home for a while, and I would like to invest in something
that will really help.
I've read about 2 different foams that may help - Icynene and
AirKrete. Both are poured into the walls and expand making a vapour
barrier. Small holes are made in the drywall and the material is
poured from the top.
The R Value of air Krete is 3.9 per inch, Icynene 4.
Has anyone used either of these two products? I think its going to be
a major investment, and I'd like to make the most out of it. With
similar R values, its hard to choose between the two on anything other
than price. I can get grants of up to $1500 from the federal
government, which should cover a fair chunk of it.
James
nicks...@ece.villanova.edu
>The R Value of air Krete is 3.9 per inch...
That's very hard to believe.
Nick
James
According to their website, they had Dynatech, an independant lab test
it. The results for a 1.63 inch slab at 75 degrees was R of 6.3, which
approximates 3.9 per inch. Icynene claims similar results.
Its a foam. It traps air.
You have an experience to contradict their statements?
James
nicks...@ece.villanova.edu
>> >The R Value of air Krete is 3.9 per inch...
>>
>> That's very hard to believe.
>>
>According to their website, they had Dynatech, an independant lab test
>it. The results for a 1.63 inch slab at 75 degrees was R of 6.3, which
>approximates 3.9 per inch. Icynene claims similar results...
>
>You have an experience to contradict their statements?
No. I confused it with R1.05 "aerated concrete." Air Krete is interesting,
at 2.07 lb/ft^3. And $2/ft^2 vs 20 cent fiberglass in a 2x6 wall?
Does that include the wire mesh?
Nick
James
Neither of the two products I've seen require any wire wesh. They are
designed to be poured in from a hole in the drywall and fall down,
filling in around pipes and wires. I have seen pictures of the Icynene
sprayed in between roof joists, but its a different formula and has a
lower R value. I'm thinking it would have to be lighter or stick
better since it isn't covered or screened.
In my situation, and I'm sure similar to many others, the cost of
ripping out the drywall to re-insulate justifies the higher cost. The
added benefit is that it creates a vapour barrier as well.
James
Jeff
> Due to increasing heating bills, I am looking at re-insulating my
> walls and attic.
>
> The house is a two story house built in the mid 70s, with brick
> exterior on the bottom and aluminium siding on the upper floor. I'm in
> the greater Toronto area, my heating source is all electric baseboard
> and installing a furnace would be a major renovation since I have no
> ductwork. Gas was not available on the street when the place was built
> but has been for sometime. I have also considered bringing in gas to
> put in a natural gas fireplace in the basement, and replacing the
> electric water heater with a gas one.
>
> The attic is straightforward and easy to do myself - the fibreglass
> has settled and I need more.
>
> The walls are another matter. I do think they were insulated at the
> time of building with loose cellulose, but I think over the course of
> 30 years, it has settled and/or shrunk with moisture. I think I will
> be in the home for a while, and I would like to invest in something
> that will really help.
>
> I've read about 2 different foams that may help - Icynene and
> AirKrete. Both are poured into the walls and expand making a vapour
> barrier. Small holes are made in the drywall and the material is
> poured from the top.
You still need to pour below the the firebreak, or you'll have an empty
cavity there.
>
> The R Value of air Krete is 3.9 per inch, Icynene 4.
Dense Pack cellulose is rated at R13 for a 3.5" wall. That works out
to R 3.7. I don't believe there are any settling problems as this is
quite dense.
I don't see the advantage in the foam fill for the cost. Cocoon is 33
SF per $8 bag (2x4 16" center). That should just be a few hundred
dollars for your house. That's provided you do the labor, otherwise the
calculations are different. I *think* Icynene is around $2 SF, or about
8 times as much.
These guys claim dense pack has a higher R value:
http://nationalfiber.com/uploads/universe/docs/wysiwyg/documents/Cellulose_Compared_to_Icynene.pdf
I'd take the money saved and use it elsewhere, perhaps in upgrading
the windows.
I've done the cellulose in my 20's house and like it. Perhaps I would
have liked Icynene also, but I wouldn't have been able to afford it!
At any rate, you are doing the right thing by upgrading your insulation.
Jeff
James
>
> I'd take the money saved and use it elsewhere, perhaps in upgrading
> the windows.
>
> I've done the cellulose in my 20's house and like it. Perhaps I would
> have liked Icynene also, but I wouldn't have been able to afford it!
>
> At any rate, you are doing the right thing by upgrading your insulation.
>
> Jeff
settles, and if it gets wet it looses part of its R value.
Part of the process for government rebate is a before and after energy
audit. I chose a company that is independant - it does not install
anything, it only does audits for a living. Hopefully they can help
steer me.
You may be right, maybe its worth doing the cellulose and windows for
the price.
James
Jeff
I think if you have water in your walls you have a bigger problem than
insulation. Cellulose breathes a bit and can absorb some moisture with
no ill effects toward it's R value.
As far as settling, I think this is a minor issue if you install
this correctly. All you do is drill a 1" hole a few feet above the
bottom, and another a foot below the top (That ensures that if you have
a fire break, that you are both above and below it). The machines blow
at considerable pressure, and you'll want a machine that you can
throttle back the insulation flow (this is just a gate, but not all
machines have them). You fill first from the bottom and then top off the
top. This is dense packed and when the it stops filling I can assure
you that no more insulation will fill in! It's pretty solid and will
resist poking a finger in. It's about twice the density of loose fill
and actually makes a good sound barrier.
Now, I don't know for a fact if I will get any long term settling,
but I do know that when I insulated walls I had missed two years earlier
that I went back to refill some of the original walls and found that I
could add no new insulation. They were still packed.
The biggest problem in installation is not blocking the nozzle as it
can be hard to clear out. Stop the machine after each cavity is filled
and start at the next. Also, it helps greatly to break up the insulation
before you put it in the machine.
http://greenfiber.com/homeowners/how_to_retrofit.asp
They have a toll free number if you want to talk with someone, I did...
Jeff
Anthony Matonak
...
> I've read about 2 different foams that may help - Icynene and
> AirKrete. Both are poured into the walls and expand making a vapour
> barrier. Small holes are made in the drywall and the material is
> poured from the top.
I've heard something about Icynene foam producing cyanide gas
when it burns. You might want to look into polyurethane foam
instead. Even there you might have to make sure they don't
use penta-BDE or deca-BDE for fire protection as there are
rumors it's a bit toxic.
The last time I looked at AirKrete it was very expensive.
Anthony