My current mud/laundry room was once an exterior porch (enclosed decades ago). I removed all the layers of flooring down to the original planks thinking I would refinish it or do tile or something. But then I started thinking what I really want is to raise the floor to the height of the kitchen floor, which you currently have to step up into from the mudroom by about 8" through a doorway.Then I can widen the doorway and basically "expand" the kitchen a bit.
I've seen a lot of how-tos for building a floor on top of a concrete slab to raise the height, but nothing that specifically mentioned raising a wooden floor....So is the correct way to do this to install rim joists around the room then install new joists, then subfloor, etc Or, are there any other methods?
If the above method is the way to go - a few questions:
- Should the joists run parallel to the existing joists in the original floor (length of the room)?
- Should there be insulation between the raised floor and old porch floor? If so what kind is best (moisture is a factor from the basement--old cement floor, stone foundation, and the sump well/pump is below the mudroom. However there is some ventilation and we use a dehumidifier down there as well).
- Should the rim joists be bolted into the studs? Or screwed? I saw one post that used 3 wood screws per stud, another that used bolts instead.
- Would I just leave the existing drywall in place and install the rim joists over it?
More info: The mudroom sits above an unfinished basement with a stone foundation and a cement floor. There is an full bathroom (also added decades ago) on the second story above that matches the footprint of the mudroom. The room measures approx 6.5' x 19'.
The ceiling height of the mudroom matches the ceiling height of the kitchen, and there would be adequate ceiling height if the floor is raised. I would have to address the issue of the exterior door, (which opens onto a covered patio) because it would then be too low with the floor height change.