Leveling a Concrete Slab
I’m planning to start a basement reno next week. I’ve decided on 1 inch XPS with 5/8 tongue and groove plywood for the subfloor. The assembly would be fastened with tapcons.
I’m just curious to know how level the concrete slab needs to be before I install the subfloor. My slab is fairly level however there are some low and high areas. Some difference is elevation is up to 1/4 inch. This difference is only in select areas. Is this acceptable before I put the subfloor? I was looking a grinding down the high spots. As for the low spots initially I was going to pour some self leveler but everyone who I talk to says that it will crack if I try to drill into it.
So really I’m just looking to see if a 1/4 inch differential in the concrete slab is ok or not, especially of the the low areas.
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