Manufacturers generally recommend that the deflection of the subfloor system be limited to no more than span 360 under total load.
Tile over osb wall.
Concrete board concrete board also called backer boardcomes in 1 4 and 1 2 thicknesses and is usually sold in 4 x 6 sheets.
In this episode of tiletv we answer the popular question can i install tile directly over osb.
You can tile over plywood proper grade of ply because the proper thinset will bond with the continuous layer of wood veneer.
Hence osb is rarely used for an underlayment tiler.
When plywood panels absorb water they swell wherever the water is absorbed.
It should be fastened to the subfloor using thinset and then screwed down every 10 square.
Osb will stay swollen while plywood will shrink back to its original thickness because the compaction force is lessened.
When tiling to osb the thinset has to try to bond with wood strands or wood chips and the resin or binder that holds the chips together.
There are two materials commonly used for laying ceramic on plywood or osb that are applied before the tile.
Tile can be safely installed to the redgard coated osb with one of custom s polymer modified thin set or medium bed mortars.