Putting in drains, do this first
Putting in drains, do this first
Before you undertake DIY plumbing and drains work it is essential to understand the national rules and regulations developed by the local authority.
If you are considering altering your existing drainage, or installing a new drainage 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 regulations. However, you will probably not have to inform the Local Authority for replacement of damaged parts or sections of sewage as permission will have already been granted for the initial installation.
Whatever water we see on the surface around your home is usually rain. 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. To stop any nasty odours emanating from the drains a combined system will discharge the surface water into the foul water drains by way of the gully traps. However, the latest systems are designed in a way which separates the foul water and the surface water. It is extremely important to ensure that you do not connect foul water to a surface water drainage system. 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.
To properly prepare the plans and get local authority permission to commence work there is a need for you to plan the route of the waste pipes before you begin. The basic thing which you have to care about is to keep the route as straight and short as you can while designing the route of a waste or soil pipe, this will help to reduce the likelihood of stoppages. If the pipe slope is excessive, your joint alignment may fail. Using surveyor’s site level you can calculate the fall of a drain over a distance to check the values. 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.
The stability of the existing house is of prime importance it should be not compromised while the drain pipe ditch is being installed so check you are not impacting on the existing structure. If you are laying a drain 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. You should attempt to get the pipes laid as soon as possible and, after inspection and checking, you should back fill the trench.
Weak soil may require that you shore up the walls of the excavation, particularly for deeper trenches. It is no advisable to not take any risks. If in doubt add support to the trench to prevent it from collapsing. Keep the trench as narrow as you can but of course make sure that there is enough room to work in the trench including any plan, machinery or tools you require. The trench base must be smooth and clean, there shouldn’t be any bricks or protruding stones around. 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. A comprehensive support should be used for the whole of the pipe.
The sewage system should be designed in a way that pipework remains accessible to drain rods should drainage maintenance work be required. Which means that a run of drains must be installed straight between two points. 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.