Domestic Plumbing Systems
Introduction
Generally speaking, domestic plumbing consists of two types of water systems:
- Mains water supply
This is the 'fresh' water supply to the house from the water mains. - Waste, or drainage, system
This consists of the waste water exiting the house from sinks, toilets, etc.
Depending on the age of your house and the type of hot water system you have, each of these water systems can operate in one of two ways.
Mains water supply
Mains water entry to a domestic property can either be direct or indirect. The easiest way to tell which one you have is to consider which type of hot water (central heating) system you have.
If the water in your home is heated using a gravity fed hot water system, then the mains water entry is classed as 'indirect'. This is because the mains water is fed directly to the cold tap in the kitchen and a cold water storage tank (usually found in the loft space) - thus all other taps, showers, WCs (toilets), etc are fed indirectly via the cold water storage tank.
If you use a combination boiler, or an unvented 'Megaflow' system, then the mains water entry is considered to be 'direct'. This means all the taps, showers, kitchen/laundry appliances, WCs (toilets) etc are fed water directly from the mains, at mains water pressures.
Many modern properties utilise a 'direct' system, which does have the advantage of minimising the amount of plumbing required in the loft space, and does also mean that showers and taps operate at a greater pressure - ideal if you prefer a powerful shower. The main advantage to an 'indirect' system is that you are not without water if there is a temporary mains failure.
Water drainage
For the majority of houses built in the UK before the 1960s, the waste water from a property is split and drained in 2 distinct ways:
- Waste water from baths, sinks and washbasins is drained into a trapped gully at ground level, which in turn flows into the main sewer network.
- Water from toilets feeds seperately into a large bore vertical waste pipe which runs directly into the sewer network.
Modern houses operate a 'single stack waste system', whereby all waste water, iresspective of it's point of origin, drains directly into the main sewer network via a large bore waste pipe.
Clearing blocked pipes & drains
Both internal and external pipes & drains can easily become blocked overtime, not only will the water cease to drain away easily but smells from the drain can make their way into the property, and at worse damp can form as a result of walls remaining wet.
By regularly unblocking them you can save yourself a lot of hassle in the long run.
Drainage in the building regulations
The building regulations on drainage & waste disposal are designed to protect all of our health and safety. Before undertaking work on your soil and waste pipes or drains (except for emergency unblocking) you must contact your local authority.
- The water bylaws are designed to prevent the misuse, waste and contamination of our water. You local water supplier can provide you with all relevant information.
Locating and shutting off the mains water supply
The mains stopcock is often located in the kitchen, either under the sink or in a base cupboard unit on an outside wall. However, depending on the age of the property, it can be in any number of places.
To help locate it look for the following clues:
- The cold water tap in the kitchen should be fed from the mains water supply, trace the pipework from the tap.
- The main water pipe entering the property will often be in either the kitchen, garage, laundry or basement - the stopcock should be near this entry point.
- The rising main water pipe, this will be a vertical pipe that carries water directly from the mains to the loft space water storage tanks, and is often against a wall in either the kitchen, laundry or sometimes the garage.
Once the stopcock has been located, turn it fully clockwise to stop the mains water. This will remove the back pressure of water in the system, thus any taps left running should reduce their flow quite noticably - if this doesn't happen then you haven't turned off the stopcock!
Draining and refilling the system
If you have a leak, or wish to add, for example, a new tap, shower unit, wc cistern, then you will need to fully or partially drain the system to be able to remove and replace the desired pipe or piece of equipment. Use the link below for our guide to draining refilling the system.
Further information and useful links
- Find a Plumber near you
- Find a Gas Engineer near you
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