A fairly obvious consideration when you’re working in the bathroom, regardless of whether your project is a remodel or a new home construction, is water-proofing. There is a lot of plumbing in that area, and there are certain areas where leaks would cause more havoc than just annoying dampness. Drains, for example. Not only is there the problem of mold, but more serious sanitation and structural integrity concerns start to kick in when your drains are not functioning.
I remember rather vividly an occasion when my parents had decided to remodel their bathroom. The demolition started one day, and suddenly, the man working in the shower fell through the floor. The ancient shower pan and drain system had evidently allowed enough water through, and the joists below had molded and rotted to the point of being unable to bear the weight of a man with a tool belt. Needless to say, my parents felt that their decision to remodel had been serendipitous — nobody wants to fall through their shower floor while using it.
It’s difficult to see that type of degradation during your normal daily life. That’s one of the reasons it’s so important to be sure that your shower and bathroom waterproofing are done correctly right from the start of your project.
In shower construction, there are two layers which resist water penetration. The upper layer is the visible tile and grout, which should be sealed after installation. Below that, however, between your tile and the supporting sheet rock, is the real barrier to the demons of mold and disintegration. There are two common methods of waterproofing: a cement board with an application of a liquid coat of water resistant compound; and a waterproof membrane set directly over your sheet rock.
It might be easy to assume that the water resistant compound with the extra layer of cement board was more efficient than the membrane — however, the opposite is true. First of all, the words “water resistant” versus “water proof” should give you a clue about what is going on. Secondly, the compound must be applied properly and very thoroughly, as well as aged for a period of time, to be effective. It is difficult to ensure complete coverage.
A waterproof membrane, on the other hand, can be easily rolled out over your setting material, usually a thinset, and with a proper overlap of 3.5″ at each seam is virtually impenetrable. The tile can be set directly over the membrane with no additional bulky layers. The same method is used for both the shower pan and walls, with the exception that the mortar bed in the shower pan is laid down and sloped to the drain before the membrane is applied.
The annual rainfall for the Boise area is around 12 inches per year. Compare that to an average 2,482 inches per year of water hitting your shower walls and floor, penetrating your tile and grout layers, and attempting to insinuate its way into the underlying structure of your home. Concerned yet?
If you’re wondering whether your current shower is watertight, a simple method is to cover the drain and fill your shower pan with water. Then, check to see if there is any leakage underneath or around the base. Check in the crawlspace also, if that is available to you, to see if there is evidence of mold, dripping, or discoloration. If so, don’t wait until it becomes a major issue! Protect your foundations and health with proper water containment.
Written By:Heidi Blodgett
Schumacher Tile & Stone
Technical Source: Tag Gibson
Schumacher Tile & Stone, Commercial Department
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