Welsh Water Build Over Agreement
This section has been written for owners who might consider building an extension or making changes. It describes the most important impact drainage can have on your project. If you decide to continue your project, your contractor will need to consult the approved H document in order to obtain detailed information on compliance with the building rules. The flow path should avoid obstacles (for example. B ponds or outbuildings) and keep them away from the foundations, so it has to be longer and have additional access rooms instead of running in a straight line. The approved H document provides guidance on the additional measures required when exits are to be near the foundations. Hardstandings surface water must not flow on the highway, where it can cause accidents or nuisance. To carry the flow and avoid obstructions, the flow or pipe you want to connect to should normally be at least 0.8m below ground floor level. If it`s less than that, you should seek advice from a contractor, architect or drainage engineer. Surface water drainage carries rainwater (and melted snow and ice) from hard surfaces. The surface system of gutters and rainwater pipes is called roof drainage; underground pipes are called surface water sewers and surface water channels. Additional rainwater pipes may be discharged onto the ground or into new or existing underground pipes. If you decide to let rainwater pipes drain onto the ground, you must ensure that the water does not damage the foundations (z.B.
by encouraging it to spread over a large area) or drain over nearby land (for example. B by A light lip at the border). The location of rainwater pipes, piles of sanitary pipes and external sewers may indicate where their underground sewers are likely to pass through. If you intend to build a public channel or find yourself nearby, you need a written agreement from your wastewater water supply, so you should consult with the company during the first planning phase of your work. The normal way to do this is to extend the piping (known as the ventard) outwards, so that the end is open (but protected by a net to prevent birds). To prevent odours from entering a building, the open end of the ventilation hose must be extended by at least three metres to the side or up to 0.9 m above an opening in a building. The pipes must be sized for the flow of water to minimize the risk of obstruction and allow air movements. Indications on the size of the pipes are available in the approved document H. In order to avoid an increasing risk of flooding elsewhere, it is best to insulate them on permeable soils or to make them from permeable materials. Permeable materials include both porous materials (z.B in the form of grass or reinforced gravel, porous concrete or porous asphalt) and permeable materials (e.g. B clay bricks or concrete blocks designed for water to pass through joints or cavities). This will not only minimize the impact on the environment, but also avoid the cost of drainage.
There are two drainage systems you need to think about: fault and surface water. In general, these two systems must be maintained separately. Therefore, you need to tell us if you are planning to expand your home so that we can make sure that your home and our pipes are protected during and after construction.