Foundation cracks. Help!

[Roselin G.]

Hello BP family! I am purchasing a house that is in construction. I went by and noticed several cracks in the foundation. They are small cracks but there are about 5-6 of them. The house is abt 2000 sq ft. I brought it up to the builder who responded that concrete cracks and thats why we have a warranty. I wanted to get your thoughts also. Thank you in advance!

[Benjamin Seibert]

Hey Roselin. This could be a variety of different items. I worked as a geotechnical engineering intern for a year and performed many inspections on cases such as these (following behind a licensed engineer). A couple the most common issues are as follows:

1) Contractor back filling up against the foundation without installing the first floor supports. Most contractors will do this even though many contracts warn against it. Without the first floor being installed there is no bracing for the foundation wall to rely on and it can easily crack. 

2) Improper drainage. Incorrect drainage is the issue for many older homes having foundation cracks as the added pore water pressure from the rain creates an uplift force and can cause differential forces on the foundation (a foundation's enemy is not always more force but it can be less force to retain the foundation as well).

Just know the wall wont crack on its own. Forces are being applied or taken away either on the inside, outside, above, or below. It may help just to take a look at everything and see if there is anything that jumps out to you (if it looks incorrect, it may be incorrect).

Note: there could also be bracing inside the basement pushing out on the walls if it was incorrectly set.