I've been reading tons on how to do a subfloor for my basement and I don't seem to be getting any closer to an answer. So far it looks like there are 4 ways to do this: (I'm stealing a good part of Chris Jaynes answer from Should I use a subfloor for a finished basement's floor?).
Additional concerns that I have are that I want to put in cabinets with a peninsula. According to This thread, cabinets shouldn't be installed on floating floors.
And then of course, there's this problem of what to do with the existing steps.
It should be mentioned too that I'll have an unfinished portion of the basement (maybe 25%), so not sure how that affects different solutions.
The Old Fashioned (6mil + sleepers + plywood)
Tried and true method
No insulation - cold. Nails penetrate barrier and allow the moisture in, causing mold down the road.
XPS foam insulation under 5/8" plywood subfloor (Mike Holmes / BSC recomended)
Cheap Good R-value to provide insulation from cold. Feels almost as warm and soft as a regular subfloor
Opinions vary about how long the foam will last before breaking down Installation instructions vary wildly (some anchor directly to floor, others anchor through wood bracing, etc.)
Opinions vary about how much air circulation the foam would allow
1" XPS + 2x4 Sleeper + 5/8" plywood = 3 1/8" sub-floor
DRIcore-style subfloor tiles
Dimpled underside allows excellent air circulation over concrete Feels almost as warm and soft as a regular subfloor Most come in 2'x2' tiles so there are no 4'x8' sheets to lug around Easy install, much like a "floating" hardwood floor Nothing anchored into the concrete (except maybe interior walls??)
- Most expensive option
- Installation calls for 1/4" gap at the edges to vent. This would vent the moisture into the wall cavity (that can't be good) if you have unfinished walls, or you are supposed to leave at least a 1/8" gap in your trim to allow it to vent into room. I have issues with this:
- If you leave a 1/8" gap then your baseboard isn't nailed into anything but the drywall
- You have an ugly gap under your quarter round
- Dust and whatnot can (and will) get pushed/sucked under the floor where it is moist, causing future problems
Platon/Delta-FL underlayment under 5/8" plywood subfloor
Dimpled underside allows excellent air circulation over concrete Feels almost as warm and soft as a regular subfloor Much cheaper than the DRIcore tiles, because the Platon is purchased separately in large rolls
More difficult to install than probably any other option 4'x8' plywood subfloor is no fun to lug around Requires the subfloor to be anchored to the concrete Many people complain of "clicking" noise.