Helping a friend tile her kitchen counter, I'm making my bill of materials. Just want to double-check one thing.
Question is: what thickness plywood should I use?
The plan is to put plywood over cabinets, then "wonderboard" (1/2" cement-fiberglass board) over that, using thinset to bond it, then tile over that. I was planning on using 1/2" plywood (counters are 24" deep), but now I'm wondering if I should use 3/4". Or would that be overkill?
And what grade? Seems to me that since it's there for support only (the cement board provides the smooth surface for tiling) that I could get away with something like CDX.
Thanks to those who can provide helpful advice.