Hello Everyone,

A contractor just recently poured a garage slab in our new construction home. The job is in Wisconsin so obviously with the weather right now I am concerned about the cold affecting the concrete. When the job was poured it was a 35 degree day and dropped into the high 20s that first night, the next day was around 30 degrees and dropped to the mid 20s the second night, and then the 3rd day it was mid 20s during the day and dropped to single digits that night. It only got colder outside from there.

The contractor did not cover the garage door entrance and did not cover the concrete with anything. approximately 7 days after the pour I went back to the house and there are dark spots on the newly finished concrete surface.

My question would be is this normal looking, will the spots go away if washed; or is this due to the cold temperature and lack of protecting the concrete during the curing process. I am concerned of potential strength and spalling of the concrete surface.

Thanks for everyone's help.

Edited by tawatt84 (01/04/18 05:26 PM)