it is very common now a days to see most contractors using cement board on the walls in tub/shower areas. It has largely replaced moisture resistant sheetrock which has been used for years especially before cement board was available. Moisture resistant sheetrock is still used everyday and is an excellent product for all the walls and ceiling of your bathroom, just not in the tub/shower area. When sheetrock is used in the shower area it will most likely fail due to the fact that it is moisture resistant and not water proof. Once water infiltrates under the tile sheetrock becomes susceptible to water damage and may crumble.
Today moisture resistant sheetrock has been replaced in the shower area with cement board creating a more sound base that will last. Also a superior product for your floors underlayment before installing tile and can even be installed in thinset and screwed down for a thorough installation. Cement board is a water proof product and will not deteriorate when in direct contact with water. Cement board is made using actual cement with a fiberglass mesh exterior.
Common cement board uses:
- Bathroom walls and floors.
- Kitchen countertops
- Soffits in bathrooms
- Exterior uses before stucco or cultured stone is installed.
- Kitchen floors.
The conclusion is that cement board is the only product you should be using when there is any chance of contact with water. Many times it's what you don't see behind the walls that has the biggest impact for longevity of your project. Toxic mold is usually unseen until the damage is too late and run the risk of rotten wall studs that can ruin the integrity of your homes structure and attract unwelcomed insects such as carpenter ants and termites that can do a vast amount of damage. Especially the presence of termites are hard to detect as they tunnel inside of wood rarely seeing daylight leaving appearance of wood on the outside perfect while the insides are hollow. This is mostly a concern with structures on ground levels that are close to the ground as they return to the soil where they live.
