Putting in a sewer, do this first
Putting in a sewer, do this first
The first thing that you will need to think about when undertaking any DIY plumbing and sewage are the rules issued by your Local Authority.
If you are changing your current sewage, or installing a new system, you will most definitely be asked to show detailed designs of the implementation that you have in mind and it will need to be overseen as the work moves forward to ensure that it is compliant with local building rules. If you are simply replacing damaged sections of the sewage, in most circumstances they do not need to be informed.
When rain falls on your house and property, it runs across as surface water and has to be drained properly. In older properties this surface water can find its way into the foul water drainage system, but more generally it can also end up in a watercourse, surface water sewer or soakaway. The rainwater pipes in combined sewage systems empty their discharge into the foul water drains through gully traps, this prevent foul air from escaping outside creating odours. But modern systems are especially created so that dirty water and surface water remain separate. If you have a modern system it is very essential that you make sure that you do not accidentally integrate the foul water to a surface water sewage system. When in doubt about the how the modern drainage system works, consult the Building Control Department.
Before you begin, you will need to plan the route of the waste pipes. Have an eye to future maintenance when you design the sewage system and always try to keep the waste or soil pipe as straight and short as you can when you are devising the layout. You should not make your pipe runs very steep although some slope is necessary. You can calculate the fall of a drain over a distance using a surveyors site level. 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 drain pipe trench is being installed so check you are not impacting on the existing structure. If you are laying a drainage run parallel to the building, you must ensure that any foundations are not undermined.
If you try to dig all the trenches before you start pipe fixing, there is a chance of some trenches collapsing. Get the pipes laid quickly and, as soon as they have been tested, fill the ditch back in.
Weak soil may require that you shore up the walls of the excavation, particularly for deeper trenches. Take he utmost care when doing this work. It is better to provide support to the ditch walls than allowing the ditch to collapse. Keep the ditch as narrow as possible, but allow room to work in the trench. Protruding stones or bricks should not be left in the base and it should be cleaned to provide a smooth, regular surface. You may have to bring in the right type of material for the bottom of the trench if the one that’s already there is not proper.
Pipework must be uniformly supported by the soil bed, and not by stones or bricks haphazardly placed underneath the pipes. This will damage the pipe and must never be used as temporary or permanent support. Consolidate the bottom with a small roller or rammer and provide grooves in the bed to support the joints properly. You will need to provide a continuous and uniform support for the complete length of the pipe.
An important criteria for pipe layout is that you should be able to access any point with a drain rod to clear blockages. This need for drain rod access can be easily achieved by keeping the pipeline straight and in short sections. As a general rule, any change in direction of the pipework should be provided with an inspection chamber to allow rodding access.
DIY plumbing and sewage is within the reach of many DIY fans if you follow these simple rules.