1. Materials
Plastics

2. Polypropylene (PP)
Polypropylene in a commonly used plastic in the plumbing industry.
It is used to make cold water cisterns, WC siphons, push-fit waste and overflow pipe.
PP is tough, flexible and resistant to most acids. PP has a low melting point of 160°C and starts to soften at 100°C.
PP deteriorates in sunlight and cannot be solvent welded.
PP is supplied in 3m lengths and is available in a variety of colours including white, black, brown and grey.

3. Polypropylene Pipe Clip Spacing
Maximum Support Distance
Maximum distance between expansion joint
Vertical
Horizontal
Waste pipe size
32mm
0.5m 2m
40mm
50mm
0.9m

4. Polyvinyl Chloride (PVC)
PVC is available in three main types; each is slightly different and has advantages and limitations over the other.
Unplasticised polyvinyl chloride (PVCu)
Modified unplasticised polyvinyl chloride (muPVC)
Chlorinated unplasticised polyvinyl chloride (cuPVC)

5. Unplasticised Polyvinyl Chloride (PVCu)
This plastic is used mainly for push-fit and solvent weld soil and vent pipes, solvent weld waste pipes, below ground drainage, gutters and rainwater pipes.
It has good resistance to UV light but can lighten in sunlight.
It has a high coefficient of linear expansion.
It is available in 110mm, 50mm, 40mm, 32mm, and 21.5mm

6. Maximum Support Distance Maximum distance between expansion joint
PVCu Pipe Clip Spacing
Maximum Support Distance
Maximum distance between expansion joint
Vertical
Horizontal
Soil pipe size
82mm 2m
0.9m 4m
110mm 1m
160mm
Waste pipe size
32mm
0.5m
40mm
50mm

7. Modified unplasticised polyvinyl chloride (muPVC)
This plastic is used for solvent weld waste pipes and overflows; it is trougher than PVCu and performs better at higher temperatures than other plastics.
It is available in 50mm, 40mm, 32mm, and 21.5mm

8. Chlorinated Unplasticised Polyvinyl Chloride (cuPVC)
This is an older plastic used for solvent weld cold water pipes in late 1970’s fitting are still available so repairs can be carried out but it is increasingly harder to source.
This plastic is brittle especially at low temperatures or if roughly handled.

9. Acrylonitrile Butadiene Styrene (ABS)
This plastic is used for soil & waste pipe and the associated fittings.
Because of its toughness ABS can also be used for mains water pipe, but care must be taken as it degrades quickly upon exposure to UV light.
The range of goods produced in ABS is the same as PVCu.

10. Polyethylene (PE) Polyethylene comes in;-
Medium Density Polyethylene (MDPE)
High Density Polyethylene (HDPE)
The majority of modern PE pipes are MDPE. It is hard wearing used for gas and water.
It should not be used above ground as it is susceptible to UV light. Very resistant to mechanical shock and freezing.
MDPE is available in sizes from 20mm to 63mm and is supplied in coils of 25m to 150m.

11. Polybutylene (PB-1)
Polybutylene is the newest plastic that has been used in pressurized plumbing pipe.
The pipe is very flexible and has good handling properties for pressure and temperature.
PB-1 is gas permeable allowing air to pass through the wall of the pipe; and in the early days this lead to an increased failure of central heating systems as the heavily oxygenated water caused excessive corrosion within the system.
Modern PB-1 pipe incorporates a gas barrier layer, pipes with out the barrier may be used for hot and cold water installations but must not be used for heating systems.
PB-1 is available in 10mm, 15mm, 22mm and 28mm and comes in 3m lengths and coils of 25m, 50m and 100m.

12. Polybutylene Pipe Clip Spacing
Pipe diameter
Horizontal Distance Between Clips
Vertical Distance Between Clips
10mm
0.3m
0.5m
15mm
22mm
0.8m
28mm
1.0m