Expert: Ted Barnhill (Principal, Design45 LLC) - 1/21/2010

Question
Hello Ted,
I want to self build a concrete house.
How long after the concrete strip foundation is cast can they start laying blocks on the strip foundation.

Answer
Bolaji,
In practice, it is common to begin laying block 3-7 days after the footing pour.  At this point, your concrete will have about 60-70% of its final strength, or at least 2000psi.  Since you won't be fully loading the footing until much later when your house is done, you don't need the full rated capacity of your footing, which is reached after 28 days of curing.  (Though the concrete keeps getting stronger after 28 days.)  I have seen folks lay block one day after a footing pour, but if you plan to do this I recommend using high-early-strength concrete and checking out its cure rate to make sure.
Best of luck with your new house,
Ted Barnhill
Design 45 LLC