Below grade foam protection (Styro Industries Q...)

[sands35]

Collecting parts for some work on my new garage.

Planning on installing some foundation foam around the perimeter of the garage.

Thinking though mechanical protection of the foam board.

There is the Styro Ind. stuff at menards:
http://www.menards.com/main/buildin...h-on-foundation-coating/p-1458072-c-13074.htm

I could also use aluminum roll flashing.

Frankly, the roll flashing isn't that much cheaper, but it seams like a bit less work to get it on that dealing with the brush on stuff.

Anybody ever do the Styro stuff? How easy was it? Was the container estimate for coverage accurate? (Will put it onto EPS. No sense in spending the money on XPS for a non-load bearing application)

 

[Steve in Mi]

Foam protection at grade level. (maybe not what you were interested in)

I used 1" Dow on the exterior from the footings to the peak and aluminum flashing to protect it from the ground level to T1-11 siding around the perimeter. I bought the 24" wide brown, cut the roll in half on the band saw and slipped about 1-1/2" up behind the siding. Allowing for doors I had enough for my 28' X 48' shop. Fill more than covered the bottom edge. Very easy to put on and no maintenance. Installed in 1981 and still looks good with some slight fade on the South side. I wonder how many times I might have had to reapply the brush on stuff?

 

[Twiggss]

I was think about making a thread about this stuff but about being above grade. Half of my basement is exposed and wanted to try to cut down on some of the heat/cold that gets transmitted through the block walls.

 

[sands35]

Steve - Thanks for the advice (I'm in SE MI). Roll flashing is attractive just because I don't need to mess with the mess of paint/goop.

Did you use adhesive or fasteners to hold the flashing on?

 

[Highbeam]

Will put it onto EPS. No sense in spending the money on XPS for a non-load bearing application)

EPS and XPS are both acceptable for load bearing applications. Not sure where you heard otherwise.

 

[Steve in Mi]

Steve - Thanks for the advice (I'm in SE MI). Roll flashing is attractive just because I don't need to mess with the mess of paint/goop.

Did you use adhesive or fasteners to hold the flashing on?

IIRC, large head roofing nails on ~ 3' centers. Nailed into my bottom plate.

Correction: Actually I installed the flashing first and then the siding allowing it to overlap the flashing.

 

[Steve in Mi]

(Will put it onto EPS. No sense in spending the money on XPS for a non-load bearing application)

If you have frost, and I know you do in Mich., you have a load on the foam - even if it is seasonal.

Also, the Dow rigid foam I used had a higher "R" value than the moldable polystyrene board.

 

[sands35]

If you have frost, and I know you do in Mich., you have a load on the foam - even if it is seasonal.

Yes, good point. I don't think I need 25psi stuff though. 10-15 PSI is good enough. There will be ~2 feet of dirt and at most a person walking over it for the lateral insulation wings.

 

[Steve in Mi]

Sands35, is this garage already built? Are you talking about a foundation of block or pour to below the frost line? Do you plan to heat it? Fulltime heat? To what temp.?

The load due to frost I was referring to is horizontal. I don't have a number in psi. but if it will lift drive aprons and road beds and I assume the force exerted is the same in all directions - well then?

 

[sands35]

Already up.

32x26
42" below grade deep footings.

For a 1 story garage, no footings are required, just the foundation walls. Soil has enough bearing capacity to do without footings. So the contractor dug the foundation and poured without forms.

In floor radiant, 2" of foam with vapor barrier under the floor.

There is about 1' exposed foundation that I want to protect with some insulation.

The part that I missed on the quote and prep work was that the foundation walls and the floor are monolithic. i.e., no thermal break between the floor and the exposed foundation wall on the outside of the building. So I need to insulate the exterior of the foundation/floor. (nuts, oh well...) From the quote work that I did, this way saved ~5-8k in costs up front. We'll see what I think about that in 20 years though. haha.

I was going to do foundation insulation anyway. I need to put in a gas line, electrical conduits, surface water drains and gutter drains. I only want to dig around the foundation once, so, here we are.

 

[Steve in Mi]

There is about 1' exposed foundation that I want to protect with some insulation.

The part that I missed on the quote and prep work was that the foundation walls and the floor are monolithic. i.e., no thermal break between the floor and the exposed foundation wall on the outside of the building. So I need to insulate the exterior of the foundation/floor. (nuts, oh well...) .

You are right, you do need to insulate the exterior foundation wall. 2" would be better if you can transition it into your structures exterior. Will the pour (without forms) be smooth/flat enough for the rigid foam to lay against? Maybe a sprayon foam is a possibility if it is real uneven.

I'm also in agreement that no thermo break floor-footings is a bummer. The above will certainly help to reduce the resulting heat loss.

I hear you on redigging around the footings, I had to re dig a lot of mine but it was easy going in the fresh clean fill sand I put around my foundation to hold the 1" rigid foam against the block both inside and outside the foundation walls plus 1" Dow rigid foam under the floor.

You're on the right track and I'm sure you will have a great garage to be comfy in.

 

[sands35]

I didn't mention that the exposed 1 foot was formed with 2x12s... It is smooth and overhangs the rough below grade work an inch or so.

I ordered some nylon drive nails and will pick up the foam monday. Still need to decide on AL flashing or the styro goop.