Finishing My Basement – Do I Need a Subfloor? (1969 Floating Slab, NE PA)

Finishing My Basement – Do I Need a Subfloor? (1969 Floating Slab, NE PA) Hey everyone, I’m in the process of finishing my basement and need some advice on whether I should install a subfloor or if I can go straight to LVP. House Details: • Built in 1969 (Northeast PA) • Floating slab concrete floor as you can see in the picture I have a border cut out. I'm guessing it's a French drain type never really knew if floating slab was the same as French drain, but it does go to where the sub pump is. • Sump pump (only one minor water event in 9 years due to pump failure, ~¼” of water that subsided quickly) • Floor is painted with gray paint (no visible moisture when testing with taped plastic, but the paint could be acting as a barrier) My Plan & Questions: I’d prefer to avoid putting down a subfloor if possible. My ideal plan would be to install LVP directly on the concrete, possibly with a dimple membrane underneath for some airflow and moisture control. 1. Do I actually need a subfloor like DriCore or a dimple membrane with plywood on top? 2. If I do need a subfloor, should I frame my walls on top of the subfloor and screw the framing directly into it? That doesn’t seem very secure to me. 3. Would LVP with a dimple membrane underneath be a good middle ground, or am I asking for trouble? I’d love to hear from anyone who’s done a similar project, especially in older homes with floating slab basements. Thanks in advance! submitted by /u/Boring-Classic-8754 [link] [comments]

Feb 11, 2025 - 22:11

Hey everyone,

I’m in the process of finishing my basement and need some advice on whether I should install a subfloor or if I can go straight to LVP.

House Details: • Built in 1969 (Northeast PA) • Floating slab concrete floor as you can see in the picture I have a border cut out. I'm guessing it's a French drain type never really knew if floating slab was the same as French drain, but it does go to where the sub pump is. • Sump pump (only one minor water event in 9 years due to pump failure, ~¼” of water that subsided quickly) • Floor is painted with gray paint (no visible moisture when testing with taped plastic, but the paint could be acting as a barrier)

My Plan & Questions:

I’d prefer to avoid putting down a subfloor if possible. My ideal plan would be to install LVP directly on the concrete, possibly with a dimple membrane underneath for some airflow and moisture control. 1. Do I actually need a subfloor like DriCore or a dimple membrane with plywood on top? 2. If I do need a subfloor, should I frame my walls on top of the subfloor and screw the framing directly into it? That doesn’t seem very secure to me. 3. Would LVP with a dimple membrane underneath be a good middle ground, or am I asking for trouble?

I’d love to hear from anyone who’s done a similar project, especially in older homes with floating slab basements. Thanks in advance!

submitted by /u/Boring-Classic-8754
[link] [comments]