Warning: I was setting post concrete in the rain for years until a city inspector in Charlotte shut me down.

3 comments

3 Comments

That "dusty and weak" top layer sageross mentioned is called laitance. Read about it on a construction forum once. It happens when too much water rises to the surface during the cure, and it just makes a weak, crumbly crust. That inspector really did save a huge headache.

sageross1mo ago

Yeah, that "water messes with the curing process" part from @the_lucas is so true... I've seen slabs that got poured in a drizzle end up all dusty and weak on top, just flaking apart after a few months. It's one of those things you don't think about until you see the damage. That inspector doing a shut down probably felt harsh in the moment, but man... they really did you a solid. Saved you from having to go back and tear out and re-pour a whole patio or something later.

the_lucas1mo ago

Guess the inspector saved you from a future lawsuit. Water messes with the curing process big time.