Part of my garage was going to be below grade so to make things easy, we
did the whole 1st floor block. Now I'm really regretting it due to high
heating and cooling costs. My original plans were to stucco the outside
of the block. It looks like 10 times the work and a lot more money to
put 1/2" or 3/4" foam panels, then wire lath, then stucco. Besides the
obvious I'd have to tear out and redo 3 windows, one door, and do
something up top were the stucco would now meet the vinyl soffit to
allow room for the foam panels. I know the foam panels aren't the best
insulation, but it would triple or quadruple the current r-value of 8"
block (about 1.11 r-value).
My other choices of course include framing and insulation the inside of
the block walls. Or maybe the foam panels outside with something else
besides stucco covering it? I suppose it doesn't have to look as nice
as I had hoped since only the front with 2 garage doors will really
show. With the garage doors covering most of the square footage of the
front wall, I could still just stucco that part right over the block.
What about not framing out the inside, gluing 1" foam on the inside and
cover it with drywall. But screwing drywall to block doesn't sound like
fun? What if the drywall was glued onto the foam panels which is also
glued to the block, and just had a few screws to hold until the glue set
up. I'm picturing blue screws with fender washers, not a pretty sight,
but it is just a garage/workshop.
Open to all... well, MOST suggestions.
I imagine you could glue it all up. Do the foam first, when that has
cured, do the drywall. If you used contact cement on the drywall, you
might not even need the tapcons and fender washers. Even with regular
construction adhesive you could take them out after it cured and mud
the holes when you were taping the joints.
Just be sure you get the appropriate box extension rings for your
electrical boxes and you might need to pigtail on longer wires. That
is easier to do before you start doing the foam.
Given your problem I would contact an Icynene installer and price out
2 x 4 framing with 3 1/2" foam filling behind drywall (INSIDE). The
way higher insulating value of such an installation will definitely
have a reasonable payback period compared with the limited options you
could do other wise. Your personal tax expert could also advise you of
energy tax credits available to sweeten the project cost.
Once the framing is in place you can add electrical outlets, water
lines, air lines, whatever, prior to the foam operation. From an
appearance standpoint this is also a win-win situation as no external
changes will be obvious to your tax assessor.
Forget about the attitude that it is 'only' a garage/workshop'. For
the hours you will spend there, there is no common sense reason not to
have heat and AC. My little 26' x 26' shop is heated/cooled and there
is no way I would do otherwise. Projects get done more quickly, tools
don't rust from excess humidity and list goes on. The shop is a major
utility at our house, like laundry. And a money saver to boot.
The only reason I considered outside stuff was from some posts here
regaurding different insuating technics for heavy mass wall. Forgetting
that idea and putting stucco directly on the block will be much easier
and less expensive then having to deal with wire lath.
Ah, I got some info now. For Icynene brand foam on 2x4 walls, with 1/2"
gap between the 2x4 wall and the block wall.
A) $1.35 square foot
B) $1.20 square foot
"A" was a guestimate from the secretary, she wasn't quite sure.
I talked shop with "B" and he also stated that they don't subtract
square feet for windows and doors except for the front where there is
more garage door square footage then wall square footage. The time they
spend taping windows and doors evens out with the extra labor. Sounds
like a good family owned and run business.
Does anyone here know what they charge in your area? Maybe other brands?
By saying that it is "only" a garage/workshop was referring to the looks
of tapcons and fender washers. My last garage/workshop had heat and A/C
also and I don't consider it a luxury.
I called the 2 closest Icynene dealers (43 and 44 miles away) and I am
waiting for rough over the phone estimates, then next would be an on
site estimate, or maybe a price quote?
I understand the reasoning why the Icynene is so much better because it
fills in cracks and stops air infiltration, but in my last stick built
garage I believe I insulated it better than 99.9% of contractors, paying
very much attention and detail for the fiberglass to expand properly and
sealing off air infiltration and air convection currents on both sides
of the insulation. That was 24x32 sq', up in PA, and heat cost me $100
to $175 per winter. That was with a oil/hot air furnace from a mobile
home. It was left at 50-55F unoccupied and about 65 or more when
working in there. What I'm trying to say is that if I do fiberglass
myself, it will be far better than in the fiberglass/Icynene comparisons.
I'm still looking for an affordable heater that is approved for garage
use. In the old one I suppose I was lucky the place never burnt or the
insurance company could have blamed the non code heater. I have a
mobile home LP heater sitting in there, trying to find out if the
insurance company will approve its use. (like my other posts, there is
no building code to follow, I only have to go by what my insurance
The "fix" (or fixes) at this point depend heavily on environmental
conditions where the garage is located.
AZ or OR...(I'm too lazy to look up your IP address)
Who did the design & who signed off on the plans? Did the designer
know the garage was to be heated & cooled?
How much of the garage is actually below grade?
The key to how successful the fix you choose is............. how well
it handles the local moisture conditions. Just throwing up some
insulation & drywall may cause more problems. :(
btw are the blocks filled or hollow? If currently hollow, filling
with perlite "might" be an alternative but I doubt it will improve
the situation a great deal. :(
Just a SWAG but I think (if unfilled) you'll go from an R of about
1.5 to maybe 5 by adding perlite.
If the blocks are filled (grouted) you've got an R of about .6
and no way to add cavity insulation.
Before the soil was graded, after some very heavy rains, 3 blocks showed
moisture. Since the grading was finished, and still no gutter it hasn't
got wet and we had some very heavy rains. It will have gutters soon anyway.
Every 4' is rebar and filled with concrete. On the side that is about
1/2 under grade is 12" block. I had some extra concrete and rebar so
that wall is filled every 2'.
I was looking for this figure on a web page and couldn't find it. Even
if all of it was filled with perlite, it's hard to believe it making
that much difference, but that's just my guess.
Contact a local foam insulation contractor to get a quote on
injecting expanding foam into the block cells. This is a normal
installation on commercial work. It involves drilling small holes
above and below any trough blocks in every block cell line. The
foam looks strange as it oozes out of the holes, but once cured
and cut off flush with the block face it is undetectable, ready
Very cost effective.
Keep the whole world singing . . . .
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