Pipes and Fittings: A Simple Guide to Sizes and Materials
Know the material, the diameter and the type of connection before you buy pipes and fittings.
Pipes and fittings are hidden behind walls, so it pays to choose them well the first time.
Material. Plastic pipes such as PPR are widely used for hot and cold water supply and are joined by heat welding. PVC is commonly used for drainage. Metal pipes and brass fittings are used for threaded connections, valves and some supply lines. Each material has its own use, so check what is suitable for your job.
Diameter. Pipes and fittings come in different diameters, and a fitting must match the pipe it joins. Check the size printed on the pipe or the old fitting and bring it with you or send us a photo.
Fittings. Elbows change direction, tees split the line, reducers join two sizes, and couplings join two pipes. Valves let you shut off water to one area without stopping the whole house, which makes repairs much easier.
Sealing. Threaded joints are usually sealed with PTFE tape or a suitable sealant. Do not over-tighten, because that can crack the fitting.
For large or hidden installations, ask a qualified plumber to plan and carry out the work, and test the lines under pressure before closing the walls.
General information only. For installation and major plumbing work, ask a qualified plumber.
