Context: I am looking to finish my basement, mostly DIY.
- The original builder installed what I understand to be a "wall wrap" on all exterior cement walls. This looks like ~1.5" of fiberglass insulation covered by a clear plastic sheet.
- The builder laid three drain pipes where the bathroom would be. I'm looking to use these drains as-is without modification.
- From what I understand, when framing a basement that has a wall wrap, you want to preserve the insulating value of the wall wrap by not compressing it. Start the 2x4 wall 1.5-2.5" away from the cement.
Problem: It appears like when the original builder laid the drain pipes, they did so without taking into account the width of the wall wrap. This means that all drain locations are off by whatever width I allow for the wall wrap to go uncompressed (or even exist). This is problematic for two of the three drains: the toilet and the shower, both of which need to be in specific locations.
Toilet: This is a problem that I believe I've solved, but would like to confirm. Standard toilet drains are 12" off the finished wall, from the drain's center. In my case, the center of the toilet drain was placed 16" off the cement wall. When measured coming off the cement wall this means: 2" wall wrap + 3-1/2" stud + 1/2" drywall = 6 inches. This leaves 10" of space where I can install a slightly non-standard toilet that has a 10" rough-in size. Any issue you see here?
Shower: This is where I don't yet have a solution. In my case, the center of the shower drain is 8-3/4" off of a preexisting load bearing stud wall, and 17-1/2" off the cement wall. In looking around for basic showers, I have found a few similar to this Home Depot shower. When looking at dimensions guide from the manufacturer, I see this shower expects to be mounted directly to the studs, with the center of the drain being 8-1/2" off one wall and 13-7/8" off the second.
Herein lies the problem of the wall wrap. 13-7/8" + 3-1/2" stud = 17-3/8", which leaves no space for the wall wrap to exist, even compressed. And that is the confusing part; the builder appears to have perfectly laid out the shower drain as to fit some standard shower dimensions, except they forgot about the wall warp? The toilet is a simpler problem to solve, as 10" rough-in toilets exist. But I don't see the same for showers.
Potential Solutions: As I see it, the following are options, but I may be missing something obvious.
- Remove the wall wrap from the cement walls along the basement. Frame flush against the cement wall.
- Find a pre-made shower with a drain closer to the side wall.
- Spend more money and build a custom tile shower. Can't even use a standard pre-made shower pan.
- Bust up the cement, and move the drain 2".
What would you do in this situation? Any help would be appreciated. Thanks!