CPVC vs UPVC Pipes, the Best Pipe Types and Common Sizes

Choosing the right pipe is one of the key decisions in plumbing works, because it determines how the network copes with temperature and pressure and how long it lasts. This guide compares the most common types, explains where each fits best and lists common sizes for guidance.

CPVC vs UPVC

Item	CPVC	UPVC
Material	Chlorinated PVC with higher heat resistance	Unplasticised, rigid PVC
Temperature	Suitable for hot water within the manufacturer’s limits	Cold water and drainage; not for hot water
Typical use	Hot and cold water supply	Soil and waste, stormwater, venting and some cold-water lines
Jointing	CPVC-specific solvent cement	PVC solvent cement or rubber-ring joints depending on type

Best plumbing pipe types by use

There is no single “best” pipe — only the right pipe for each job:

• PPR: one of the most used options for hot and cold water supply inside buildings, heat-fused into a continuous network.
• CPVC: an alternative for hot and cold supply, joined with solvent cement.
• UPVC / PVC: the common choice for drainage, stormwater and venting.
• HDPE: for mains, underground runs and irrigation thanks to its flexibility and toughness.

Common drainage pipe sizes

Diameter	Typical use*
40 – 50 mm	Basin, sink and shower waste
75 mm	Branch lines and some floor drains
110 mm	WC branches and main stacks
160 mm and above	Main horizontal drains and connection to the network

Common water supply pipe sizes (PPR)

PPR pipes are ordered in common outside diameters such as 20, 25, 32, 40, 50 and 63 mm. Smaller sizes feed individual fixtures, larger sizes serve mains and risers.

* Sizes are for guidance only. Diameters, falls and pressure class are set by the designer based on the number of fixtures, network design and project specification.

See our plumbing pipes and fittings page, and learn the part names in our plumbing fittings names guide.