I recently pulled some drywall off an interior basement wall to expose the sole plate of the wall framing. I was surprised to see that the 2x4 sole plate was recessed into the basement floor about 3/4". Is this normal? Any ideas why the home builder might have done this?
Bob ~ Madison, WI
Hi Bob. I agree that seems a little odd and there are only two scenarios that come to mind that might result in your situation. I have seen builders put in foundations and frame new homes prior to pouring the basement slabs due to the weather being extremely cold and being concerned with the concrete freezing before it has a chance to cure. They then go back and pour the slab when the temperatures begin to rise. However, I have never seen any wood framing installed in the basement prior to the slab pour. Normally any structural material that the slab might be poured around is steel. Even if your builder happened to install some wood first, the basement wall would be much deeper than 3/4 inch -- in fact you wouldn't even be able to see the sole plate.
The more likely scenario is that the basement was finished after the home was completed and due to the condition of the concrete slab, the contractor decided to float the floor to even out the surface. It may even be in just one section where the floor had to be cut up for plumbing pipes and due to the floor coverings the differing floor heights aren't obvious. It's still a little odd though as pouring a top coat on the slab is normally done before any new basement walls are built, unless the wall was already in place such as at a stairway or to provide a location for laundry rough-ins. While I've heard the winters in Madison can be very cold, I think the second scenario is probably what happened.