Accidentally “built” a poor wall?
Have read through many of the assembly techniques here in the past, including the guidelines on insulating with rigid foam to avoid condensation / moisture accumulation and filed it all away as “stuff to worry about if / when we make changes to the house”.
Fast forward to earlier this week… I went up to my son’s room and went to straighten up the sheets on his bed, only to find that there was a large amount of water underneath the side of the bed closest to the wall. The floor underneath the wet side was freezing to the touch (barely warmer than the outdoor temperature).
The room is partway over an attached garage — based on the insulation in the rest of the garage, my guess is that the current layering as-constructed is:
1. Hardwood floor
3. R-19 fiberglass batts
Now we get to the part where I think I accidentally “built” a poor wall — since my son is only 2 and we were concerned about the possibility of him falling off a taller bed, sitting on top of that assembly I put a 12″ high density foam mattress wrapped in a waterproof cover, which makes the final assembly:
1. Vapor barrier
2. 12″ foam
3. Vapor barrier
4. Hardwood floor
6. R-19 fiberglass batts
Cleaned up the water and moved the bed away from the wall and no more moisture is showing up on the floor. Floor over the garage is a little colder than the rest of the room, but much closer to the indoor temperature than it was before.
Does my “poor wall” hypothesis sound correct? If so, does that mean the only real option for having a bed along that wall will be to have it raised with some provision for heated air to circulate underneath?