A home is going up right next door, and I noticed that the foundation walls have 2x4’s embedded in them. Won’t that cause the concrete to crack when the wood gets wet?

Foundation #1 Foundation #2

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    Are you sure those are 2x4s? instead of 1x2s as a nailing surface for some sort of facade or cladding? – DaveM Aug 15 '18 at 1:53
  • They’re definitely 2x4’s. Wouldn’t even a 1x2 be a problem though? With temperature changes (0-110F here in KS) and moisture, it will either crack the concrete or push itself out. – Andy Edinborough Aug 15 '18 at 2:00
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    I'm not a concrete or structural engineer, but I doubt they would push out, and cracking, I wouldn't know. The internal rebar should prevent some of that. I hope they are pressure treated, because even though they are above grade they would make a great path for termites or carpenter ants. – DaveM Aug 15 '18 at 2:09

Most certainly the embedded 2X4s are pressure treated (PT). Any PT lumber off the shelf usually has about as much water it can hold from the treatment process. If anything they will shrink. I can only hope they are keyed in or have hot dipped galvanized nails so they stay in place after they shrink. DaveM is on poi t I believe about the nailing for a facade, and because of that, there be plenty chance for them to dry and not get saturated again.

About the cracking, concrete will crack anyway, there is reinforcement added to prevent it from becoming a problem.

  • Some of them actually touch the ground. Won't they rot? – Andy Edinborough Aug 17 '18 at 12:53
  • The wood really should be pressure treated, if not who ever installed the 2X are foolish to think they will last. Anything in contact with the ground needs to be pressure treated. Not just any pressure treatment, because there is treatment for above ground AND ground contact. – Jack Aug 18 '18 at 4:02

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