There's some confusion in the remodeling market about waterproof sheetrock. It was intended to be a backer board in areas where there's a lot of moisture or humidity. Over time though, it's been discovered that waterproof sheetrock will eventually fail in 3 to 8 years, so contractors are using wonder board instead.
Waterproof sheetrock is also called green board, water proof green rock and several other names. It's traditionally been used in bathrooms, basements and other rooms where there's high humidity. Waterproof sheetrock is really moisture resistant and not waterproof; therefore the name is a bit of a misnomer.
About Waterproof Sheetrock
In bathrooms, the tile and grout is not waterproof. Water can seep beneath the tile into the substrate material. Once this happens, there will be rapid rot in the bathroom walls. One thing about waterproof sheetrock is that it was intended to be a substrate under tile in shower enclosures that would prevent moisture from reaching the wall studs. As it turns out, green board is ideal for those areas where direct water does not hit. Waterproof sheetrock has a moisture resistant paper backing which can be useful in certain areas of the house.
Instead of waterproof sheetrock, the best tile substrate is wonder board. Wonderboard is fiber glass reinforced cement board that's water proof, insulating and sturdy. When you use waterproof sheetrock in a bathroom, you'll most likely have to replace it eventually. You'll never need to have wonderboard replaced as long as a moisture barrier is installed underneath. Your remodeling contractor can install wonderboard during new construction or during a remodel.
Sheetrock is formed by making a sandwich of gypsum between paper layers. Green board is gypsum sheetrock between paper layers which have been wax coated. As technology progresses, it's anticipated there might be a true waterproof sheetrock on the market one day. But if you're planning on having your bathroom remodeled, it's important for your contractor to use the right materials in areas where there's a lot of moisture. These areas can include bathrooms and basements as mentioned, and also hot tub or spa rooms.
Wonderboard is more expensive than waterproof sheetrock initially, but pays for itself in a short period of time since it doesn't have to be replaced when installed correctly. Of course, in addition to using the right kind of substrate in your bathrooms, an exhaust fan should be installed also. A general contractor can show you how to build or remodel your bathroom in a way that prevents water damage as the years pass.
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