What is the appropriate gap between gypsum board and a tub surround?

What is the appropriate gap between gypsum board and a tub surround?

• A. 3/4 inch
• B. 1/4 inch
• C. 1 inch
• D. 1/2 inch

Answer: (B)

A small one-quarter inch gap is used between gypsum board and a tub surround to accommodate movement and allow for a proper seal. Humidity, temperature changes, and settling cause both drywall and tub surrounds to shift slightly at different rates; forcing them to touch can transfer stress, leading to cracks or finish damage along the seam. Leaving a quarter-inch space gives room for this movement and provides a surface to apply waterproof silicone caulk, which keeps water from seeping behind the drywall. A larger gap isn’t needed and would require more caulk and look less tidy, while a smaller gap wouldn’t leave enough room for a reliable seal or movement.

A small one-quarter inch gap is used between gypsum board and a tub surround to accommodate movement and allow for a proper seal. Humidity, temperature changes, and settling cause both drywall and tub surrounds to shift slightly at different rates; forcing them to touch can transfer stress, leading to cracks or finish damage along the seam. Leaving a quarter-inch space gives room for this movement and provides a surface to apply waterproof silicone caulk, which keeps water from seeping behind the drywall. A larger gap isn’t needed and would require more caulk and look less tidy, while a smaller gap wouldn’t leave enough room for a reliable seal or movement.