Overview of drains pipes installation
Overview of drains pipes installation
Before starting any plumbing and drainage work yourself you should find out about any Local Authority rules that relate to your area.
If you are considering altering your existing sewage, 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 don’t need to inform them if you are just replacing some damaged parts.
Surface water is basically rainwater. 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. In a combined system, the rainwater pipes are discharged into the foul water drains via gully traps which stop foul air escaping from the drains. Nowadays hygiene and recycling considerations have led to a mandatory separation of surface water and sewage water. To comply with modern planning regulations you should always make sure that the foul water and surface water sewage 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 sewage.
The first thing to do in a DIY sewage replacement job is to decide the position and level of the waste pipework. The route should be as short and straight as possible, this will help to reduce future maintenance problems and costs. 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 home is of prime importance it should be not compromised while the drain ditch is being installed so check you are not impacting on the existing structure. Keep the drain pipe excavation at a uniformly safe distance from the house face to avoid damage to the foundation.
Try to leave as short a time as possible between digging the ditch and installing the sewage system as an empty ditch represents a danger with the potential for a sidewall collapse. The pipes should be laid quickly and the ditch back filled after the system has been examined thoroughly and tested as required.
Depending on the depth and soil conditions, the trench may require support. Take he utmost care when doing this work. If you have any worries, you should support to the trench to reduce any risk of collapsing side walls during the building phase. 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. The base should be good so you may need to import material if the existing soil structuire is not up to the mark.
You should definitely not use hard materials such as bricks to support the pipe in the trench. Such hard objects will cause the poorly supported pipe to bend or break and the joints will eventually fail. The material used for bedding should be firmly compacted down with a depression created to allow the joints in the pipes to fit easily. A good guideline is that support should be provided for the entire length of the pipe.
Make sure that your plans are made in such a way that drain rods are within reach of every part of the network of pipes. The drains should therefore run straight between two points to ease the passage of the drain rods. As a general rule, any change in direction of the pipework should be provided with an inspection chamber to allow rodding access.
Following this guide you can see that DIY plumbing and sewage can be delivered by conscientious DIY enthusiasts.