View Single Post
Unread 03-02-2019, 10:42 PM   #12
Registered User
Join Date: May 2017
Posts: 211
I am back at the house with every tool and spare supply I think I could use. Took a closer look at the joist structure and found the following:
The joists are 9"x1.5" on 16" centers.
They are marked ILMA S Dry 1, 37 SPF. I gather this means they are "surface dried" spruce, pine, or fir, grade 1. The house was built in the 70s I think.
The supporting beams running perpendicular are 15' apart, so I take it the joist length for the calculation is 15'.

If I plug all that into the Deflecto I get L/226, ruh roh. Here's some additional info that perhaps would improve the situation?
- the area in question is adjacent to the support beam. The drain is ~18" away from it.
- the joists in this area are overlapping, so 24" out from the beam (about 6" further out than the drain) it's a double wide joist section. For some reason there's a 3rd piece sistered in on the ones immediately next to the drain. You can see this in the photo above.

For what it's worth the floor in the area not adjacent to the toilet looks OK, no cracked tiles or grout.

Tomorrow starts with tearing out the 6 affected tiles and determining the extent of the damaged wood. If it's contained to that area I'm figuring to remove both layers of ply, put in some additional blocking, and then go with whatever combination of ply layers and ditra or Strataheat mat (I have large enough scraps of both to cover the space) will get the new tiles to the same height as the existing ones.
greenjp is offline   Reply With Quote