I plan on finishing my basement and I have a specific question about framing the walls and protecting the soleplate.

I plan on framing and setting up the walls BEFORE laying the subfloor, but that means I need to protect the soleplate from moisture. I plan on sealing the entire basement (thankfully it's fairly new and there are no cracks in the floor), but when I anchor the soleplate to the floor, it will obviously break this seal and potentially allow moisture to seep up around the fastener.

Should I do any of the following?

  1. Put caulk/glue under the soleplate where I know I'll be anchoring it
  2. Use washers or some other inorganic spacer to elevate the soleplate off of the concrete
  3. Use a pressure treated soleplate

I would rather not lay dricore first and then frame on top of it as that makes the dricore much harder to remove if there is ever a flooding issue. I'd also prefer the walls to be more stable than if they were anchored to dricore subflooring.

3 Answers 3


Any framing that directly contacts concrete should be pressure treated. So option 3. Sealing is an optimistic concept at best, .vs. ensuring that there is proper drainage outside the basement, but you could certainly put construction adhesive on the bottom of the soleplate, it won't hurt.

  • Is sealing worthwhile just to keep away moisture seepage? I know it won't hold back water under hydrostatic pressure, but is it at least good for reducing or eliminating weeping? Apr 28, 2014 at 6:27
  • This is the correct answer, but I will add that you man consider an additional "capillary break" which not only blocks seepage, but will plug the occasional gap where spiders like to hide. diychatroom.com/f19/bottom-plate-capillary-break-133518
    – Paul
    Apr 28, 2014 at 18:59

You can't really stop leaks in concrete from sealing from the inside. Products like DryCor and epoxy seals are temporary solutions to water leakage problems, at best.

So if you have seepage issues, just do not finish the basement, as you will not want to rely on sealant as your only line of defense.

If it's just natural moisture that you are concerned about, then I don't think you need to over-think the penetration of a few nails into the concrete.

But you do not want untreated wood in contact with the concrete, so you're right about that.

Using pressure treated lumber will prevent rot, but not prevent it from wicking up moisture. So that's only half-solution. What you really want to do is create a break between the concrete and the wood. Two options off the top of my head:

  • Rubber window flashing on the floor, wood floor plate nailed on top

  • (my preference) 1/4" EPX foam, metal floor plate nailed on top.

I prefer using metal framing for basements for a number of reasons that I outline here.


You want water to escape, not sit. Ideally, you want a series of things:

  1. Have a place for moisture in the basement to go. A sump hole with an optional sump pump at the lowest part of the basement is ideal.
  2. Use a pressure treated sole plate on these interior walls.
  3. Periodically, create breaks in the sole plate a few inches wide so in a worst case scenario the water can escape. You will put a continuous non-treated bottom plate on top of the treated sole plate upon which you will build your wall.
  4. Bring the drywall or wall sheeting material down to the untreated bottom plate, but not over the sole plate.

After the wall is framed and sheeted, put baseboard over the gap between the sheeting and the floor. A few spacers there are okay. But don't seal it.

  • Far from being "ideal", a sump hole and/or sump pump is a clear sign that things were done wrong in the first place. Sump pumps are a power drain, a maintenance issue, and tend to go dead in the middle of a big storm when you need them most if you need them at all. A simple drainpipe around the footings which drains away downhill works all the time, without needing or using power, and without eating several square feet of basement space.
    – Ecnerwal
    Apr 27, 2014 at 21:17
  • 1
    @Ecnerwal not every house is situated on a hill. My prior house would have needed several hundred feet of pipe to get lower than the basement floor. Landscaping to help direct surface water helps, but sometimes you need a sump.
    – TomG
    Apr 27, 2014 at 22:00
  • I read something once suggesting using PVC decking like Trex as the soleplate against the concrete and attach 2x4 bottom plate along that which sounds like it could be even better than pressure treated but I dont know anyone who has ever done such a thing. Apr 28, 2014 at 1:22
  • Furthermore, if we are talking about a liveable basement that has a perimeter foundation, there may be no where for the water to run to. A sump hole on the order of inches or so tucked into a corner out of the way ensures there is always a low spot for water to run to.
    – Wes Modes
    Apr 28, 2014 at 6:19

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