Q. I recall a plumber telling me some years ago ďnever use Drano for a slow drain if you have plastic pipeĒ but I donít remember him saying what would work instead. For some time one of my bathroom sinks has had a slow drain. This particular setup has two sinks, but only one is slow, so I assume the trap on the slow sink has some debris in it. It hasnít been slow enough to worry about. Now my shower drain is slowing. When I shower I find myself standing in an inch or two of water. Any idea what I can do to speed things up?
A. Your recollection concerning Drano is partially correct. However itís OK to use it on PVC drain pipes but I and most plumbers do not recommend using it on metal drain pipes, like copper or galvanized steel. Drano has aggressive chemicals in it that will tear up metals, skin, wood and most anything it lands on because itís intended to do just that so it has to be used carefully, if at all. In a previous life I worked as a compounder in a soap factory. That may not be the worst job in the world but it was worst job I ever had. From that experience I learned that the active ingredient in products like commercial drain cleaners is caustic soda (sodium hydroxide). When your clear glassware gets milky from too many trips through the dishwasher know th at itís the caustic soda in the detergent that actually begins to etch the glass. Nasty stuff.
Whatís causing your drains to run slow in the locations you mention is most probably a combination of human hair and soap scum. To free up the sink all you have to do is go underneath of the sink and disconnect the stopper and pull it out from the bottom of the sink. Youíll see a mess of hairy goop thatís slowing things down collected at the base of the stopper. Clean that off. Then, before you replace the stopper, run some water in the sink to see if it now drains better. Iíll bet it will. If not, then wait for the water to go to its lowest level then pour some laundry bleach down this drain, about a cup, and wait about 15 or 20 minutes then run the water again but this time have a small plunger in your hand. If itís still running slow-- which I doubt-- then plunge it.
The shower is the same sort of thing but without the stopper. In this case pour some bleach down drain and wait the same amount of time as for the sink then run water to see if youíve broken things loose. If not, go ahead and plunge.
OK, as a last resort use Drano. But if you do be very careful or you or someone in your house could get injured. I know. Iíve taken a trip to the ER with a flake of caustic soda in my eye. Iím lucky I still have that eye.