I just installed some 12" x 24" large format tiles in my laundry room using Flexbond mortar over concrete that was machined with a diamond cup disk. Its been ~32 hours since I finished the main portion but its clear that that the mortar is still curing. It can take foot traffic at this point but I really need to get my washer/dryer back in there ASAP because I literally have no clean clothes 😉
How long should I wait before hauling these two beasts back in there?
My washer is probably ~300 – 350 lbs (it has huge concrete blocks in it for counter balance) and the dryer is a good ~170 lbs.
Best Answer
It depends on the concrete permeability and the tile permeability (is it porcelain (essentially zero permeability) or a ceramic bisque (most non-porcelain tiles))?
A sealed concrete floor and a porcelain tile will greatly extend the cure cycle by limiting moisture migration.
It is for this reason that Schluter (a tile membrane manufacturer) specifies a non-modified (no latex added) thinset for its floor membranes and porcelain tiles together (on the tile side of the membrane). They make the same requirement on the floor side, if the floor is limited in permeability. Flexbond is VERY modified.
If sealed floor and porcelain, 48-72 hours is safe. The tiles will cure properly with EVEN compression (the weight of the washer), if spread over several tiles.
Would it be possible to temporarily put down several 1/2" ply feet, that span from front to back, under the washer/dryer feet?