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Earlier this months (Jan 00) I installed a saltillo tile floor, about 8’x 12′, in my own home. The floor consists of 3/4″ plywood subfloor, 1/4″ Hardibacker screwed down every six inches both ways, then the saltillo tiles set in latex-modified thinset. The Hardibacker was not set in thinset nor were the backer boards joints taped.
Within a week of completion the first crack appeared in the saltillos and grout, running on top of a joint in the Hardibacker. Now, three weeks later, there are cracks over all the backer board joints, in a 3′ x 5′ pattern. The floor is a failure and the only reason I don’t tear it out is that it’s in my own honme where I can observe the situation for future reference without loss of money or reputation.
This is the fourth saltillo floor I have installed and the first with problems. My earlier installations were over (1)concrete slab, (2)concrete slab with well-adhered vinyl flooring, and (3) 1/2″ plywood glued and screwed to 3/4″ subfloor (no backer board).
I did not use the fiberglass tape at the joints for two reasons. One, the Hardibacker has no tapered edges for the thinset and tape. Two, fiberglass tape cracks regularly in drywall taping and just doesn’t seem like it could resist the forces involved in floor movement.
I’d like to hear from anybody with guesses at the reason for this cracking. Also, I’d now recommend against 1/4″ backer board for floor installations.
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Earlier this months (Jan 00) I installed a saltillo tile floor, about 8'x 12', in my own home. The floor consists of 3/4" plywood subfloor, 1/4" Hardibacker screwed down every six inches both ways, then the saltillo tiles set in latex-modified thinset. The Hardibacker was not set in thinset nor were the backer boards joints taped.
Within a week of completion the first crack appeared in the saltillos and grout, running on top of a joint in the Hardibacker. Now, three weeks later, there are cracks over all the backer board joints, in a 3' x 5' pattern. The floor is a failure and the only reason I don't tear it out is that it's in my own honme where I can observe the situation for future reference without loss of money or reputation.
This is the fourth saltillo floor I have installed and the first with problems. My earlier installations were over (1)concrete slab, (2)concrete slab with well-adhered vinyl flooring, and (3) 1/2" plywood glued and screwed to 3/4" subfloor (no backer board).
I did not use the fiberglass tape at the joints for two reasons. One, the Hardibacker has no tapered edges for the thinset and tape. Two, fiberglass tape cracks regularly in drywall taping and just doesn't seem like it could resist the forces involved in floor movement.
I'd like to hear from anybody with guesses at the reason for this cracking. Also, I'd now recommend against 1/4" backer board for floor installations.