In this video, This Old House plumbing and heating expert Richard Trethewey takes a look at the wide variety of water-supply pipes.
1. Galvanized steel pipe is no longer used for supplying water, but it’s still found in some older homes.
2. Home centers and plumbing-supply stores have fittings for connecting copper and plastic water-supply pipe to existing galvanized pipe.
3. Copper tubing is the most popular water-supply pipe; it’s available in 10-foot and 20-foot lengths.
4. Type L copper tubing has thick walls and Type M has thin walls. Check with the local building code to determine which type to use.
5. Copper pipe and fittings are sweated together with solder.
6. Solder-less copper compression fittings are also available. Tighten the fittings with two wrenches.
7. Push-on copper fittings form watertight connections without using any tools. Use these fittings for repairs in tight spaces.
8. You can use CPVC plastic piping to supply water, but not PVC, which is only rated for drainage.
9. Join together CPVC pipe and fittings with brush-on primer and cement.
10. PEX cross-link polyethylene water-supply tubing comes in coils or straight sticks.
11. Blue PEX is for supplying cold water; red PEX is for hot water.
12. PEX tubing and fittings can be connected with crimped fittings, which are joined tightly together with a crimping tool.
13. PEX can also be connected with barbed brass fittings. Use an expander tool to widen the tubing end, then insert the barbed fitting.
14. Use the expander to force the fitting fully into the tubing end.