We own a home built in the late 1800s, a large attached garage was added likely in the 30s or 40s. The garage has a nice stem wall and a continuous slab. There are 3 rooms in the garage. The laundry room is about 12×11 and had a floor drain. The slab developed a large crack and had some sinking in the SE corner.
Concerned that there might be leakage from the floor drain, we had a large section of the laundry room slab (about 80%) cut out and replaced. We ran a new drain line straight out to the main and decided to have the new pour level, without adding another floor drain. The contractor installed rebar bent into an L shape horizontally into the existing slab. Not being at home during the pour, I can’t be certain he added rebar under the new pour. We’ve had some unusual experiences with the contractor.
There was old mortar left on our slab from a previous chimney removal, as well as some old paint in places. Our son in law used his cement grinding tool to remove the rebar and got a bit carried away. While he was removing old paint he also removed the feathering where new slab meets old. This left a small seam exposed.
We plan to paint the floor with Rustoleum garage rocksolid epoxy system. Question: Do we need to add some sort of bonding or sealer to this crack prior to painting? I will try to upload a photo. Thanks for any advice.