Replies

1. 
   robzan | Sep 30, 2004 10:24am | #1

   Hello.  I have seen houses built with pre-cast concrete beams sitting on poncrete piers about every 10 feet or so around the perimiter.  Maybe this is what is going on?  The first time i crawled under a house and saw daylight underneath the concrete stem wall it threw me off too.  good luck!

2. 
   DANL | Sep 30, 2004 02:06pm | #2

   I think it would be pretty hard for a 2' deep concrete wall to lift, as it would actually have to bend somewhere if the other 2 walls are still in touch with the ground. To bend 3-6", I would think there would be cracks somewhere. But to make sure, someone could sight along the top of it and see whether it's straight. (Or string a really tight line, but looking is easier and more reliable IMO. My guess is that the ground has settled--especially in new construction like your BIL has. Houses tend to settle a lot in the first ten years, then little after that.

   BTW, I would also think that if two walls had lifted that much, while rear wall is still on ground, your floors would be obviously unlevel, doors would be sticking, plaster/DW would be cracking, etc.. Don't know what foam was for, but don't think it contributed to settling (or rising).

3. 
   DanH | Sep 30, 2004 05:28pm | #3

   It sounds to me like it's a pier and beam foundation, and the soil below the beam has washed out or subsided.

   Some info on where this is (Manitoba? So Cal?) and what the terrain is like would be helpful.

1. 
   SAHarding1 | Sep 30, 2004 06:46pm | #4

   Thanks very much for the replies. I never considered that it was a pier and beam foundation, because the foundation wall looks like a poured wall (slightly non-uniform, as though created by forms). Would concrete beams be indistinguishable from a poured wall?

   There are hairline cracks in the exterior stucco, but nothing major. The interior shows no signs of cracking or being out of level. The foundation wall is level also- no dipping or sagging anywhere.

   This is in Northern California, in soil with high clay content. Except for one day this month, there hasn't been any rain for 5-6 months and the ground around the foundation is dry, hard and solid.

   The foam thing is really a mystery. I've been googling "Insu-Foam" and "R-Guard" but coming up empty. It just seems very odd that these two layers of foam would be stuck to the bottom of the stem wall.

   I appreciate the help,

   Steve

1. 
   VaTom | Sep 30, 2004 07:35pm | #5

   I never considered that it was a pier and beam foundation, because the foundation wall looks like a poured wall (slightly non-uniform, as though created by forms). Would concrete beams be indistinguishable from a poured wall?

   40' is long way between piers.  My first construction job, 11 acres of apartments in Denver, was that foundation over expansive clay soils.  We were required to remove 4" of soil under the walls, which were cast-in-place concrete, just like a normal foundation but without footing.  We first piled up the dirt, then dug it out after the pour. 

   If the clay there is expansive (bentonite), you've got the answer.  When it rains, the gap'll disappear.PAHS Designer/Builder- Bury it!

2. 
   DanH | Sep 30, 2004 11:24pm | #6

   The foam is probably there to provide a crush zone, so that the soil won't lift the grade beam.