There is an old saying in remodeling, "For the money, follow the water." This means that performing renovations in the areas where there is water - kitchens and bathrooms - will reap the most rewards for the money spent.
The typical bathroom of the early to mid part of the last century was usually a rectangular-shaped area which used to be fit into whatever space was available after everything else was thought through. Except for the closets, the bathroom was the only widely-used area that was alotted so little planning. This was because the plumbing had to taken into consideration and the pipe materials were not as advanced as we have now.
One of the main drawbacks to many of the early bathrooms was that the materials the builders had for containing moisture were not as diverse as we have now. This was made even worse because the bathroom windows were made of wood. In addition, when showers came of age they were installed on the wall over the tub – and the tub was usually beneath the window. So decades of water splashing on the window frame not only caused the window to rot but also allowed water down the walls. In many cases a bathroom remodel required the complete removal of this bathroom wall.
The modern bathroom has many features which not only controls moisture but expels it before it can cause harm to the area or to the home itself. Break-throughs in materials, especially in the substrate, and methods have made rot almost obsolete.
Waterproofing the Bathroom
Remodeling the bathroom usually requires ripping out everything down to the bare walls. However, because of the moisture inhabiting this space over the years there will usually be some damage behind the tile, tub and under the floor. This is because even in the best-tiled bathroom grout fails and fixtures move creating gaps where water can get in.
Green Board: The first material you will hear about for a bathroom substrate is usually "green board." This is a type of drywall used in bathroom areas because it is purported to be waterproof. This actually not true. Green board is just "moisture resistant" and is not intended for use in areas where water will hit the surface, that is the shower tile. A failure in the grout will then have direct water pressure on a substrate not intended for this. Instead it will work well for all other areas outside the shower, sink or bath area.
Wonderboard: This panel goes on like green board but is actually waterproof. It is a fiberglass matte board pressed with cement and screws on just like regular drywall. Although heavier and more expensive than sheetrock this board will be worth the effort because it not only will resist water but has no areas for mold to form.
Bathrom Fan: Believe it or not a lot of the rot in the bathroom can be attributed to airborne water from showering. If left inside the room this will eventually condense and the droplets will roll down into any tiny cracks in the baseboard. A good fan or ventilation system will draw this water vapor away from the room drawing in clean, dry air in the process. What this will accomplish is to take away much of a potential damaging agent before it gets a chance to condense.
Bathroom fans are chosen for an area based on exhaust capacity or cubic feet per minute (cfm). Normally, a regular-sized bathroom needs 50 cfm drawn from the room. Cheap fans not only do not have the draw they are noisy and get noisier with age. Fan noise is measured in sones and the better fans have a rating of 0.5 sones or less and use about 20 watts in power. For large bathrooms the fan should be placed as close as possible to the source of the moisture.
A great invention for those who want the beauty of a tiled shower is the pre-made shower pan. It used to be that a shower bed was made with wood and then tiled. This led to leaks, especially around the drain. Most of the pans are made from polyurethane and shaped like the shower you plan to build - square, rectangular, triangular. They take away a lot of the chances for a shower failure because they are leak proof and will not promote mold growth. In addition they provide a good base for tile and stone.
One of the newest improvements in keeping the water in control in the bathroom is the self-contained shower cabinet. These new cabinets range from a sealed shower cabinet with its own fan system to a complete spa complex with steam. Unlike the regular showers these new designs are completely sealed when the door is shut. Many have a dozen or more individual showerheads that can be pre-spotted or pre-programmed from a "smart panel" which will also control water temperature, steam output, audio-visual attachments and even chromatherapy or colored lights. In essence this new bathroom concept provides a complete spa down to the hot air-generated bubble tub.
All these waterproofing features have one goal in common - to keep water and water vapor from penetrating into the frame of the home. In accomplishing this task not only is rot and floor failure avoided but also the health risks and dirty appearance of mold is nullified.