In any industry, there are specific terms used to describe various parts or systems that are used only in that industry. The drainage and sewerage industry is no different. You might have come across the term ‘lateral drain’ and wondered what this actually is. Well, wonder no more because we’re going to explain it in more detail for you.
In essence, a lateral drain is a length of drainage pipe that carries waste water away from your property and deposits it into the public sewer system. In most cases, these lateral drains are located outside your property’s boundary usually under the road or footpath.
You might also find, in some situations, that a lateral drain will actually run under your property if you happen to share a sewer with your neighbour. This can often be the case for people who live in terrace houses or semi-detached homes as these lateral drains will collect waste water from two or more properties.
Can You Build Over A Lateral Drain?
In general, if you’ve decided to extend your home and you’re considering building within 1 to 3 metres of any lateral drain or public sewer pipes, you need to get in contact with your local water authority to let them know your plans.
On the other hand, most water authorities will not grant consent to building over or close to a lateral drain to anyone who is building a new house or planning to extend a commercial or industrial premises.
Before you start any type of building work such as an extension to your home or adding a garage or conservatory, you first need to determine whether there are any lateral drains or sewage pipes anywhere near where you want to build. Your local water authority should be able to supply you with a map that can show these.
Building over lateral drains or sewage pipes could easily damage them or may cause problems down the track with your building. It’s also important that the water authority has easy access to all lateral drains in case they become blocked or need to be repaired.
If you’ve determined that there is a lateral drain on your property that will be within at least 1 to 3 metres of your building extension, you need to submit a proposal to your local water authority to see whether you’ll have permission to go ahead with your plans.
Each water authority will have their own criteria to allow building over a lateral drain, so make sure you check what they require before you go ahead with any work.
Consider Getting A CCTV Drain Survey Done
To save yourself a lot of time and trouble, consider getting a CCTV Drain Survey done before you even consider doing any kind of extension work.
A drain survey involves putting a camera probe into your drains to both inspect them and to see where your private drains are, how deep they go and where they meet up with the lateral drains.
In most cases, this will be a requirement from your local water authority before they’ll give you permission to build over a lateral drain.
Once you’re armed with all the information of where the lateral drains are located, you might be able to amend your extension plans so that the building doesn’t come anywhere near these drains. This would be the most ideal solution and will save you a lot of time in the long run.
What Happens If You Build Over A Lateral Drain Without Getting Permission
If you didn’t get a ‘build over agreement’ from your local water authority before you completed an extension or other build on your property, it’s unlikely that you’ll be able to get a Building Regulations Completion Certificate.
While this might not be of concern to you now while you’re living in the property, it can cause some major issues if you go to sell the home in a few years down the track.
What Can Happen If You Build A Conservatory Over A Lateral Drain?
If you’ve built a conservatory over a lateral drain without approval from your local water authority, you might face some issues. Primarily, if the water authority needs to access the lateral drain, then they do have the authority to remove your conservatory without your permission.
In most cases, if the manhole can be relocated so that it’s outside of the conservatory, you should be given permission to build it over the lateral drain.
In any case, it’s far better to get the relevant approval first rather than having to deal with expensive issues later on.
Who Is Responsible For A Lateral Drain?
The local water authority that services your area is responsible for all maintenance work and repairs to all lateral drains that connect to the public sewer network. These lateral drains are usually located outside the boundaries of your property but some may not be.
If you suspect that there may be lateral drains within your property’s boundary, you should most likely be able to see a visible sign of this such as an inspection cover or a manhole cover located somewhere in your garden.
Even if you don’t see anything visible, this does not mean that there are no pipes underground that you just cannot see. Firstly, you should check the deed that was supplied to you when you purchased the property. Other than that, you can get a map from your local water authority that will indicate where the lateral drains and sewer pipes are located.
After reading this, you should now be totally familiar with what a lateral drain is. It’s the drain that carries your waste water into your local sewer system and is usually located outside your boundary.
However, some lateral drains may be situated inside your property’s boundary and may also be shared with neighbouring properties. This is important to know if you want to complete any building work such as adding an extension or a conservatory because you’ll need to get permission first before you build over a lateral drain.