How to Build a Steam Shower

A steam shower is very difficult to make. There is so much liability involved that most contractors will not bother with them. Of the several steps involved, if you do just one of them wrong, you can have a moisture problem that will destroy the shower. However, a steam shower can be built if you pay attention to necessary details; here are all of those details.

Things You'll Need

• Cross laminated virgin polyethylene vapor barrier
• Helper
• Tile
• Thinset mortar
• Trowel

Instructions

1. Install a one-piece vapor barrier. The steam generation unit creates huge amounts of water vapor. This vapor can get through grout, cement board and moisture resistant drywall easily. It can get into a wall cavity, come in contact with a cool surface and the water vapor will change into liquid water. If this happens, mildew, rot and fungus are next and your project fails. Install a high quality one piece vapor barrier on the entire inside surface of the steam shower. Most shower floors are either in a tub, have a fiberglass shower pan or are built from ceramic tile. Tubs and shower pans are impervious to water vapor and a ceramic tile floor will be as well, provided it has a one piece membrane under the cement mud base. Your membrane must be one piece that not just covers the floor and walls, but also the ceiling.

2. Find a cross laminated virgin polyethylene vapor barrier, not in big box stores, but in small companies that sell specialty concrete supplies. They will probably stock the barrier you need.

3. Do this with another person. This is a two-person job--someone has to hold the vapor barrier tight to the ceiling while the other person begins to nail it. Make certain the barrier is centered and that you have plenty of material to cover the ceiling and walls in one piece.

4. Cover all wall and ceiling surfaces with tile. The glazed surface of the tile inhibits vapor penetration and allows the steam buildup to happen faster and be more intense. Other dense natural stone or man-made stone look-a-like products can perform well also. If you use tile or a natural stone surface, use cement board as the substrate. The cement board will not deteriorate over time, but moisture proof drywall will. Apply the tile with thinset mortar, not organic adhesives. If you use cultured marble, paint the cement board with a high grade 100 percent acrylic white primer. Allow it to dry for three days. Use clear 100 percent silicone caulk to attach the cultured marble to the cement board.