Tiling Bathroom Floor – Underlayment options
After coming home from a week’s vacation to find a large water stain on my ceiling, I’ve come to discover that the toilet in my second-floor bathroom has been leaking for what appears to be quite a long time. This derailed my previous plans for a kitchen remodel – and started me on my way to remodeling the kids/guest bathroom in my 1975 colonial.
I’ve ripped out pretty much everything (including the cast-iron tub) and am down to subfloor and studs. After taking up the underlayment (1/2 inch piecemeal and very uneven OSB) I’ve discovered a lot of water damage to the (1/2-inch plywood) subfloor and plan to remove and replace with new 3/4-inch ply. My question is what to use as an underlayment for my planned tiles (1×1 marble hex on 12×12 sheets). I’ve read a lot about my options here – and am unsure which way to go. I’m leaning toward SLC due to an un-level floor (have to check again now that OSB has been removed), but if I do that – 1. do I need any other underlayment over the 3/4-inch ply subfloor? 2. do I need to use metal lath? 3. how do I seal plywood joints to keep the SLC from seeping through? 4. Am I better off just using Durock or plywood and Schluter Ditra?
The bathroom is only 6×10, and I’m just looking for some more seasoned opinions here… any suggestions/experiences are greatly appreciated. Thanks!
Replies
The key here is floor flex. How much total floor material will you have over your joists when you are done, and what is the size and span of those joists?