Bricks, Masonry, Asphalt and Concrete - Concrete delamination ?

Hi -


My newly built home has a standard concrete basement. There are small patches where the concrete has "delaminated" - I think that's the correct term. To describe it, the top layer (1mm) of concrete that is smooth has broken away from the rest, exposing a rougher surface underneath.

The obvious question I have is is this a big deal; or is it simply a cosmetic issue that's easily repaired?

It all depends on if it keeps happening now that the slab is enclosed, or whether it only happened when exposed to the elements during construction. If it keeps happening, it's a problem (still only cosmetic though, the concrete underneath is probably structurally sound).
If it has stopped now, no real problem.

There are many possible causes for the delam, including:
1) Water puddled on the vapor barrier prior to the pour, which percolated up through the slab and was trowelled in.
2) Concrete was poured too wet, and finishing operations began before bleedwater had dissipated.
3) Water was applied to the surface to aid in finishing.
4) Hard trowelling air-entrained concrete.
5) use of de-icing chemicals soon after the pour to facilitate construction.
6) concrete froze before it was fully cured.
There are other causes for delamination as well, such as dirty aggregate from the ready mix plant, etc.

Are you sure that these areas were not scratched off, or something heavy was dropped on them during construction? That could also cause the top to come off in the affected area. If you are planning on covering the floor with carpet, etc., you probably don't have to do anything to the floor. If you are leaving it bare, and the bad areas bother you too much, there are patch materials available from any hardware store or home center.

Pecos

Thanks for the reply. I can't really speak to the history of the pour or if anyhting was dropped on it -it's a spec home we first saw when it was basically finished. Someday I'd like to finish the basement. I'll probably patch it at that point.....

Post again before you try to patch it. There are special mixes available for your problem. Just any ol' concrete patch won't work.