Know your house pipes- types and uses
All houses have both water pipes and drainage pipes. It is important to know the differences between the pipes that are used within a home when building or renovating. The two main differences in pipes are those that carry clean water in and drainage pipes to carry out waste.
Water pipes
These pipes carry clean water in only from the street or drinking water tank into your house via a pump. Most homes were piped in copper piping and had soldered joins and this is still a valid and used method. However many homes are being piped with specialised plastic pipes that are flexible.
Copper pipes
- Long lasting.
- Must be soldered with a gas torch.
- Not very flexible: use fittings or bending to change direction.
- Reliable and will mostly last 50years or more.
Plastic
- Long lasting.
- Not soldering: joins are crimped together.
- Flexible can easily change levels and direction.
- Quicker to install.
Water pipes for houses come in two main sizes 15mm or 3/4 inch and 12mm or 1/2 inch. Your main supply pipes should be 15mm and then 12mm into the bathroom, laundry and kitchen.
Drainage Pipes
These pipes carry dirty water or gray and black water. However there are different sizes used in for different parts of the home.
Kitchen
Kitchens use 50mm plastic pipes to carry all waste away from the sink and the dishwasher. The S trap under the sink is also 50mm with a dishwasher connector.
Laundry
Most laundries also use a 50mm pipe as they also carry water from the washing machine and the laundry sink.
Bathroom and toilets
Bathrooms have a 100mm main sewer pipe taking the waste from the toilet, shower, bath and vanity sink. In most cases the shower uses 100mm waste pipes with an S fitting to stop sewer odour. The Toilet has an S or P trap built into the unit so it is connected straight to the sewer pipe. However the vanity and bath both use a 40mm pipes set up and thus must use connector to change from 40mm to 100 mm.
Summary pipes sizes
- Kitchen: 50mm plastic
- Laundry: 50mm Plastic
- Shower: 100mm plastic or clay in older houses
- Toilet: 100mm plastic or clay
- Vanity sinks: 40mm plastic
- Bath: 40mm plastic
Outdoor
Standard down pipes to carry storm water to the street or to tanks are 90mm in plastic.
