Types of Pipes Used in Building Construction

     Pipes are used for different purposes in building construction. There are mainly four types of piping system to be designed in building construction. They are

•  The water supply system
•  The rainwater disposal system
•  The soil and waste disposal system
•  The drainage and waste water supply system

The main types of pipes used are outlined below:

Cast Iron Pipes

     These pipes and fittings are used for soil, waste and rainwater pipe systems from decades. They are made by the sand cast process by pouring molten grey cast iron into vertically mounted sand moulds. These pipes are available in length of 1.5, 1.8 and 2.0 metre and in thickness of 5 and 6 mm.

Nowadays, ductile cast iron pipes are available in the market, which is as good as steel pipes in strength and is as durable as cast iron pipes. But, they are somewhat costly and usually stipulated for public buildings.

Plastic Pipes

     There are various types of plastic pipes are popular in building construction. These pipes are cheaper than GI pipes but costlier than AC pipes. The following are available types in plastic pipes:

1.  Unplasticized PVC (UPVC) or rigid PVC pipes are used for cold water supply.
2.  Plasticized PVC pipes, which are plasticized with rubber stabilisers fillers etc. it becomes less brittle and more   temperature resistant. The stabilizer protects the system from deterioration when exposed to sunlight.
3.  Chlorinated PVC (CPVC) pipes can be used to carry water at ordinary temperatures up to 120°C.

Besides PVC, polyethylene (PE) and polybutene (PB) pipes are also available, which are less used compared to PVC pipes.

Ordinary PVC pipes are used as electric conduits for concealed wiring. Several types in PVC pipes are used for soil discharge system inside the building including ventilation, rainwater system, potable water supply, sewerage and industrial effluents.

These pipes are available now in the market with or without socket ends and also with threaded ends like GI pipes.

GI Pipes

     GI pipes are made from steel pipes, which are available in light, medium and heavy grades depending on the metal thickness. The galvanizing process deposits a thin coating of zinc which protects it from corrosion.

GI pipes were previously the most traditional material used in water supply inside buildings. Usually, for internal plumbing in buildings, the medium grade pipes are preferred.

However, these pipes corrode easily if it carries brackish water or buried under the ground. They are costlier than PVC pipes and are available in the market up to 150 mm nominal diameter.

Stoneware Pipes

    These pipes are available with thickness varying from 12 mm to 43 mm of internal diameters 100 mm to 600 mm. These pipes are cheap and are extensively used in low-cost construction for underground drainage systems. Laying of these pipes requires experienced workers, so PVC pipes are preferred to these pipes in many places.

Asbestos Cement (AC) Pipes

     Asbestos cement pipes are cheaper than PVC pipes and were once very popular for drainage. They are still used for drainage of rainwater from roofs, soil, and waste and also for ventilation.

These pipes are replaced with PVC pipes in higher class buildings for many reasons like brittleness of AC pipes, availability of PVC pipes in long lengths, easiness in fixing PVC pipes to walls.

Concrete Pipes

    Small unreinforced concrete pipes are used for drainage of rainwater and for irrigation works. Large diameter pipes are usually made by spinning and are used for water supply works.

Even though all these types of pipes are available, PVC pipes are used widely for all the purposes. But, ordinary PVC pipes are not very durable when exposed to direct sunlight outside the buildings and also costly. The choice of the pipes will depend on the cost and expected durability. For low-cost construction, low-cost materials are preferred and vice versa.

Also Read: What is Plumbing System? Buying Guide