Pour new concrete surface over 100 year old basement concrete floor

by Corey
(Stapes, MN)

Q. I was wondering what the best way to go about resurfacing old cracked and unleveled concrete is. I have a 7'6" ceiling height with a floor that deviated by a max of about 2 inches in some spots.

There is significant cracking in some areas and areas where you can hammer chunks out fairly easily but there is sound concrete to be found under the brittle stuff. There is also occasional moisture that seems to seep through without an issue of any standing water though.

I want to end with my basement (approx 600 sq ft) having an epoxy finish like a garage. I just want it close to flat for functionality. I am not sure what product I can get to do this myself as an overlay. Tearing out the floor is simply not an option since I only have small access windows in the basement. Getting all that out would be the death of me. I also can't see pouring a thick new slab because of the already low height here.

I don't want to move forward without a bit of advice from someone who has done this or knows best. Thank you in advance.

A. If you want to have an epoxy finish on your floor, you are going to have to remove the old concrete.

Epoxy will peel off any overlay or concrete floor if there is moisture present.

Trying to apply a self-leveling overlay to a 600 sf concrete floor that is heavily cracked and out of level would cost more than replacing the old concrete with new concrete.

You can rent a small conveyor belt and remove the concrete through the windows. Better yet hire someone with experience doing this and have it done in a day.

Install a moisture vapor barrier under the new concrete floor and the epoxy, if installed correctly, will last for many years.