Plumbing can be puzzling. It all seems simple enough as long as pipes work like they’re supposed to, but that’s not always the case. Sometimes strange things happen. Here’s a look at three of the most puzzling plumbing problems, what causes them and what you can do about it.
When water pipes make pounding sounds as flowing water shuts off quickly it’s called water hammer. A sudden stop in flow sends shock waves back through the water in the pipes causing noise, rattling of the pipes and possibly damage. What you need is to cushion the halting of water flow, and there are two ways to make this happen.
If the problem is associated with one fixture only, a water hammer arrestor is the cure. It’s a small metal air chamber designed to be spliced into the water supply pipes nearest the fixture that triggers the trouble. If you have water hammer in more than one fixture, splice a pressure tank into your main water intake line of the sort people use with water pumps at the cottage or for homes on wells. The air stored in this tank cushions the sudden halt of water flow, dampening any vibrations that would otherwise cause water hammer. This tank approach protects your whole house.
If the air inside the pressure tank comes in contact with water, it slowly dissolves and disappears over time. No air, no cushion. That’s why you need to choose either the kind of pressure tank that has a valve for replenishing internal air periodically, or a model with an internal diaphragm that separates water from air.
It’s not unusual for otherwise odour-free bathroom sinks to develop bad smells, even if they’re kept clean. The culprit is often the overflow passage that opens near the top of the sink, connecting with the drain pipe underneath the sink. Microbes can set up shop in this passage, creating bad odours as they thrive.
You might think the odor problem has to do with stuff rotting somewhere in your drains, but it doesn’t. A bottle of three per cent drug store hydrogen peroxide is the most environmentally sound way to solve the problem. Temporarily plug the bottom of the overflow passage with a rag where it meets the main drain pipe just below the drain opening, then pour hydrogen peroxide down the top of the overflow opening until it’s full. Let the liquid sit for 30 minutes, then remove the rag. Your sink should remain odour-free for months.
Do you have a drain that makes gurgling sounds as water flows away? Are there chronic odours continually coming from this drain? You probably have an inadequately vented drain system. In order to operate properly, air must be allowed to flow back into any drain pipe as water flows away, and this is normally accomplished with a secondary set of pipes that connects the main drain to an air vent pipe going through the roof. The most common cause of bad drain venting is improperly installed pipes. Sometimes it can be difficult to create proper venting, so it doesn’t always happen during construction. Vent stacks can also get clogged sometimes, especially in older installations where corrosion chokes a metal pipe as it goes through the roof.
Air admittance valves are the easiest way to vent a drain that wasn’t built properly in the first place.
It’s a one way valve made to join with existing drain pipes, allowing air to enter the pipe while water drains out, while keeping sewer gases from venting into the room. Always install air admittance valves as high as possible above the drain pipe being vented. Plumbing can sometimes be puzzling, but solutions all come down to logic. It’s not hard to keep things working when you understand what flows where and how.
Steve Maxwell is Canada’s award-winning home improvement expert, and technical editor of Canadian Home Workshop magazine. Sign up for his free homeowner newsletter at www.stevemaxwell.