Mention water pipes and folks think copper or galvanized iron. Chances are that's what's in your house, but plastic pipe can also be used and, in many cases, it's a winner. Plastic costs less, fittings are cheaper and it goes in faster. On the other hand, there are very strict codes and rules for the use of plastic pipe, so first check to see if plastic is OK in your area. Then be sure your plastic pipe is properly rated for the temperature and pressure it'll carry. Also, plastic fittings aren't threaded and, while they go on faster, it's why codes require all plastic fittings to be easily accessible at all times. That means: access panels in walls, between floors and in closed attics. Personally we prefer copper for water pipes and black ABS plastic pipe for drains and vents. This gives the best of both worlds. But, for a quick repair in an open area or for a new-room addition, check it out. The plastic motto: "don't thread it, don't sweat it" may be just what you're looking for. And that's the On The House tip for today.