Do this before you start sewage installation
Do this before you start sewage installation
The first thing that you will need to think about when undertaking any DIY plumbing and drainage are the regulations issued by your Local Authority.
Detailed plans of any changing or installing of sewage in your home will have to be submitted, and expect ongoing inspections until its completion to ensure that the work abides by the rules. However you do not require authority approval for replacement of failed joints or cracked plumbing and drains pipes.
The water which you see on the surface is basically rainwater. This can discharged into a soakaway, watercourse, surface water sewer or, particularly in older properties, into the foul water drainage system. If gully traps are fixed at the junction of the rainwater pipe and the waste water drain, foul odour can be controlled. With more contemporary systems, however the foul water and surface water is kept separate, this is a more recent development. To comply with modern planning regulations you should always make sure that the foul water and surface water drainage system do not connect. The Building Regulation Department will be able to guide you on any details or procedures you may require for repairs or replacement of your drainage.
Before starting your work, finalise the routes the waste pipes would take. Have an eye to future maintenance when you design the drainage system and always try to keep the waste or soil pipe as straight and short as you can when you are devising the layout. Steep pipes should be averted during the path design. A surveyor’ site level should be used to work out the fall of a drainpipe. In case you don’t have a surveyors site level, choose a datum point and then a water filled hose can be used to calculate the fall from there.
Be very careful not to excavate too close to your building, as you may undermine the foundation and cause a structural collapse. You have to make sure that no house foundation is weakened if you are laying a drain pipe running parallel to the building.
The pipes should be laid before too long a trench is dug as a new trench can be unstable. Make certain that the pipes are laid as soon as possible and then bury them immediately after the testing and inspection are completed.
Be wary of the depth and soil conditions and if necessary add extra support to the ditch. You should avoid any risks with this project. If you are not sure prop up the ditch anyway to prevent it from falling. Keep the ditch as narrow as you can but of course make sure that there is enough room to work in the ditch including any plan, machinery or tools you require. The bottom of the ditch must be smooth and clean, free of any objects that make it uneven such as stones or bricks. If the material at the base of the trench is not appropriate then you might have to bring in new material.
Never use bricks and/or other hard materials to support the pipe in the trench. This should not be used as support for the short or the long run because it will damage the pipe, the pipe needs to be fully supported over its full lenght. Consolidate the bottom with a small roller or rammer and provide grooves in the bed to support the joints properly. For the complete pipe length you have to provide a continuous and uniform support.
It is important that all parts of your sewage system are designed so that all parts of the pipework are accessible to a set of drain rods. Thus, a drain route must be as straight as possible between any two points. As a rule of thumb, a directional change in the pipework must have an inspection chamber for rodding access as drain rods do no go around corners.
DIY plumbing and drainage is within the reach of many DIY fans if you follow these simple rules.