Finish TradesQuestion 408 of 700
When setting ceramic tile over a wet area such as a shower wall, which backing material is the BEST choice directly behind the tile?
a.Standard paper-faced gypsum wallboard
b.Untreated plywood
c.Cement backer board with a suitable water-resistive membrane
d.Oriented strand board (OSB)
Explanation
A cement backer board combined with an approved water-resistive or waterproof membrane provides a stable, moisture-tolerant substrate for tile in wet areas. Standard gypsum wallboard, untreated plywood, and OSB all degrade with sustained moisture and are unsuitable directly behind shower tile.
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