The first steps to drain fitting
The first steps to drain fitting
Before carrying out any DIY plumbing and drainage, you should first take into consideration the rules issued by your Local Authority.
You need to explain your work plan in detail to the authority if you wish to install a new sewage system or alter an existing one, the officials will then go through the plan to check if it is in accordance with the rules. However you don’t need to inform them if you are just replacing some broken parts.
If you hear the term ’surface water’ in any sewage documents this basically means rainwater. An earlier method was to directly discharge this surface water into the sewage drains, but modern homes use a surface water sewer or watercourse or soakaway to drain or absorb rainwater. In a system combining both functions, the rainwater pipes clear out into the dirty water drains through the gully traps that prevent fetid air from sneaking out of the drains. Nowadays hygiene and recycling considerations have led to a mandatory separation of surface water and sewage water. Foul water should never be connected to surface water sewage system with any new drainage development you undertake. The Building Control Department is your first point of contact before you start any work if you are not familiar with your home’s drainage system.
Before starting your work, finalise the routes the waste pipes would take. Sewage pipes must be aligned as straight as possible, with inspection chambers at short intervals. You should not make your pipe runs very steep although some gradient is essential. Use the surveyor’s site level to calculate the drain fall over the complete system. Or just fill a transparent hosepipe with water and use the water level at the two ends to mark the required fall from the starting point.
The stability of the existing house is of prime importance it should be not compromised while the drainage ditch is being installed so check you are not impacting on the existing structure. Similarly, take care of the substructures when laying a drain pipe that runs alongside the house.
When fitting in a new sewage system, you should not dig the trench too long before placing the pipe as the trench could collapse. Get the pipes laid quickly and, as soon as they have been tested, fill the trench back in.
Be wary of the depth and soil conditions and if necessary add extra support to the ditch. Do not take any risks. It is better to provide support to the trench walls than allowing the trench to collapse. The trench should be narrow, but spacious enough for people to work with any required tools. Protruding stones or bricks should not be left in the base and it should be cleaned to provide a smooth, regular surface. You may need to import a suitable material for the base of the trench if the existing material is unsuitable.
Never use bricks and/or other hard materials to support the pipe in the trench. This will damage the pipe and must never be used as temporary or permanent support. The bedding should be properly compacted with hollows made to accommodate the joints in the pipes. The support should be smooth and even, from the beginning of the pipe to its end.
It is very important that the design of the drainage system should be constructed in such a way that all parts of the pipework are accessible to a set of drain rods for future maintenance. So that is why a run of drains should be as straight as possible between two points or inspection chambers. As a general rule, any change in direction of the pipework should be provided with an inspection chamber to allow rodding access.
If you are keen on DIY and follow some basic principles then you will be able to do plumbing and sewage on your own.