Drainage program planning 1st actions
Drainage program planning 1st actions
Before you undertake DIY plumbing and drains work it is essential to understand the national rules and rules developed by the local authority.
If you are considering altering your existing drainage, or installing a new sewage system you will almost certainly need to present some detailed plans of the work that you intend to undertake and it will need to be inspected as the work progresses making sure that it complies with the local building rules. However, you will probably not have to inform the Local Authority for replacement of damaged parts or sections of drainage as permission will have already been granted for the initial installation.
Surface water is basically rain. In older properties this surface water can find its way into the foul water sewage system, but more generally it can also end up in a watercourse, surface water sewer or soakaway. 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. However, modern systems are designed to keep the foul water and the surface water apart. Rainwater and foul water drainage should not be interconnected, however convenient it may seem. When in doubt about the how the modern drainage system works, consult the Building Control Department.
Before starting your work, finalise the routes the waste pipes would take. The main things to consider when planning the route of a waste or soil pipe are to keep the route as straight and short as you can. The pipes should run straight with a gentle incline. You can calculate the fall of a drain over a distance using a surveyors site level. A hosepipe filled with water from an established datum point can be used if you don’t have a surveyor’s site level.
You need to ascertain that the foundations and structure of the building is safe when digging to install your drain ditch. Keep the drain excavation at a uniformly safe distance from the building face to avoid damage to the substructure.
The pipes should be laid before too long a ditch is dug as a new trench can be unstable. You should attempt to get the pipes laid as soon as possible and, after inspection and checking, you should back fill the trench.
You may need to provide some support to the ditch depending on the soil in that area and the depth of 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 trench 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 trench 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.
Pipework must be uniformly supported by the soil bed, and not by stones or bricks haphazardly placed underneath the pipes. This should not be used as employing this type of material as a temporary or permanent pipe support will damage the pipe. The base should be tightly packed in the appropriate manner with holes carved out to fit in the protruding pipe connections. A comprehensive support should be used for the whole of the pipe.
It is important that all parts of your drainage system are designed so that all parts of the pipework are accessible to a set of drain rods. Therefore, a run of drains should be as straight as possible between two points. In case of any change in the direction of the pipework it should be provided with an inspection chamber for allowing drains rod access.
Keeping these points in mind, you can carry out your own sewage and plumbing work smoothly and almost professionally.