Bath has many possible water problems
Q. One of our bathrooms has a musty and sometimes a sewer gas odor. I wipe out and dry the bathtub and sink, but the odor is still there. What is the source of the odor and how do I fix it?
A. There are so many sources of water, air ducts and sewage in bathrooms, it often is very difficult to precisely identify the source of the odor without an actual inspection. Having said this, there definitely are some likely areas for you to check first. These also are the ones which you should be able to fix yourself.
A musty, moldy odor is usually caused by persistent dampness in a specific area or two in the bathroom. For mold and mildew to thrive in a bathroom, they need just moisture and some organic source for nutrition. This source can be flake of dead skin from your body, soap residue, oils for conditioners, etc.
Since there also is a sewer gas odor at times, there may be a leaky wax ring under the toilet. This soft wax ring creates the seal between the toilet drain outlet and the sewage drain inlet pipe when the toilet bolted down. If the toilet is slightly loose and you can rock it, this motion may deform the wax ring and cause a leak.
When the wax ring is leaky, it allows water and some wastes to leak out on the floor. Often, the leakage stays under the toilet and you never see it, but it saturates the lumber below it. If you can rock your toilet, replace the wax ring. It is a very inexpensive part you can find at any hardware store.
If the sewer gas odor is coming from a bathroom which is seldom used, the sink or bathtub trap may have dried out. The trap elbow should have water standing in it to create a water seal to block sewer gases. For seldom used bathrooms, to be safe, pour a quart or so of water in the drains to fill the trap elbow.
Next, check for leaks in the vanity cabinet underneath the sink. Water may be leaking there without your noticing it. Deposits of soap, hair and other gunk collects in the bottom of the trap under the sink. If the plumbing starts to leak, this is a common spot. Also the seal where the sink stopper control arm enters the drain under the sink may have become leaky. You can buy replacement trap sections and stopper arm seals.
The trap in the bathtub is another possible area where water may be leaking, causing persistent dampness and a musty odor. Unfortunately, this is much more difficult to repair if it is leaking. Check the ceiling in the area immediately beneath the bathtub. You may notice a slight discoloration and a spongy feel to the ceiling drywall. It may also feel colder than other spots on the ceiling.
The musty odor may also be coming from the bathroom ceiling vent fan. If the fan duct outlet is located in side wall or roof, rain water may be leaking in. This can run down the duct and sometimes collect around the ceiling fixture. Remove the decorative cover from around the vent fan and check for any signs of moisture.
• Send questions to Ms. Builder, c/o Daily Herald, 6906 Royalgreen Drive, Cincinnati, OH 45244 or visit www.dulley.com./msbuilder.