Shower Vapour Barriers

Have you ever boiled water in the kitchen and the windows in your home fogged up? The vapours you are creating goes into the air and condensate when it meets the cooler temps of the glass windows. The same will happen in the walls of your shower. Let me explain. Where ever you place the vapour barrier in a wall is where the condensation will occur. Vapour (water) can penetrate any material until it hits a barrier. That is why it is important to position the barrier on the inside (warm side) of walls. Just because you do not see mold does not mean it is not present in your shower. I have remodeled many bathrooms in new subdivisons and have found mold in a 2 year old construction. Now why is this so? To cut cost contractors use regular sheetrock or greenboard in showers which is a recipe for disaster. When ever I begin demo, between the tile and greenboard I find mold. Greenboard is water-resistent, not waterproof. To solve this problem we use what is call Cement Boards Units (CBU). Cement boards has no components which break down or deteriorate from moisture. So using the right moister barrier with cement backer board in stand up showers and tubs is the right way to frame you bath before tile installation.