A tile installation is a durable cladding, not a structural system. It depends on a sturdy and stable base for longevity. Because wood structures expand and contract with changes in humidity - and because they are inherently flexible - they are not ideal for tile. If they aren't carefully designed and built, flexing and deflection can cause tiles to crack or shear off the setting bed.
While a 2-inch mortar bed remains my first choice as a setting bed in wood-frame construction, the next best option is a double-plywood substrate. The only problem is that plywood's rate of expansion and contraction far outstrips that of ceramic tile, which makes plywood a difficult bonding surface. Fortunately, the bonding problem is easily...
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