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Foam around foundation pad .... help please!

xtal_01's picture

WOW ... 5 times I have lost my message tyring to post (all kinds of error messages ... even a span filter alert).

I will try a very short one this time

Concrete pad with 2" of foam around it.

What do I cover the foam with?

Cement / stucco directly on it?  What if the tractor hits it.  I have huge chunks missing now.

Hardie backer then cement /stucco?  Hardie say do not use for ground contact.

I am stuck!

I read literally dozens of posts all asking the same thing.  Lots of people seem to have this problem but I don't see a good or guaranteed answer.


The rest of the story (post #215087, reply #3 of 5)

So, I got the first post up and with luck, there should be two pictures up ( message said awaiting approval).

My wife (who is paralyzed from the shoulders down) and I started building a house 4 years ago.  We lived in the 15 year old RV in the picture for 3 winters (-30 here in VT) while building.  We finally moved into the house ... a lot left to finish but warm.

I work out of the house so that I can do her care every 4 hours, plus I want the RV stored inside ... thus the 3000 sq ft workshop.

I designed it for a standard frost wall foundation with foam inside the wall and under the floor to meet Vermont Engery Code.  I did this for the house ... worked great.

The pad was poured at the same time as the house foundation.  The excavator, framer and concrete company (I acted as my own general and sub contracted out the heavy work) all convinced me to go with a pad instead.  There is foam under the pad, around the outside and outward below grade 4 ft.  No foam under the thickened edge or the 6 thickened post locations.

So, now I have two problems.

First, how do I cover the foam?  Cement / stucco over the foam scares me.  I thnk when (not if) the lawn mower hits it, the foam will crush and the cement crack as it is pushed in.

I was going to put Hardie backer but it is not rated for ground contact.

What do I do????

Second, how do I top the 2" foam.  I was thinking a 45 deg trim piece or maybe some kind of flashing.  I thin both may be a disaster plus the T1-11 may rot and / or weep water up under it.

Another idea was to bring the foam / hardie up about 24".  Then attach a second 2 x 4 wall onto the 2 x 6 wall.  This would form an overhange over the top of the foam.  No water leak plus the t1-11 hanging over would stay dry and maybe not rot?

Again, any help or suggestions would be very appreciated.


Drive the tractor carefully! (post #215087, reply #5 of 5)

If you want to apply a stucco finish (I have had excellent results with a variety of applications), you need a dense foam suitable for below grade EIFS applications. Your foam needs to be encased in stucco all around!  After the foam is installed, tape the seams. Then cover the entire thing with self-adhereing mesh. Mesh thickness determines the thickness of the stucco's base coat. Apply two base coats if you want. A thicker base coat is more impact resistant than a thin one. Then trowel on and smooth the finish coat.

Alternately, put up the foam and then cover it with metal lath. Apply scratch and finish coats. This should yield an impact-resistant foundation coating. And, uh, don't let the tractor hit anything! Even brick veneer can be damaged on impact. Stucco work is hard on the wrists. It is labor intensive. But it is beautiful when done correctly. Try it!!

Though I don't use the product myself, you can purchase pre-finished foundation foam at Menards. I believe it is only 1" thick. If you have limited construction skills this may be a product to consider. You might want to investigate if this type panel can be glued to your 2" foam panels. Whatever you do, make sure your foam panels are fully encased in stucco. Apply a water proofing compound below grade.

Mel Fros