Don't Let Your Extension Go Down the Drain!

Planning an extension? Exciting times! You're envisioning the extra space, the new kitchen, maybe even that dream home office. But before you knock down any walls or lay a single brick, there's a crucial, often overlooked, step: checking your manhole inspection chamber. Trust me, ignoring this could lead to some seriously messy (and expensive) problems down the line.

What is a Manhole Inspection Chamber, Anyway?

For those unfamiliar, a manhole inspection chamber (sometimes called a drain inspection chamber) is essentially a covered access point to your drainage system. It allows you (and professionals) to inspect the condition of your drains, identify blockages, and carry out maintenance. Think of it as the window to your underground world of pipes and flows.

Why is Checking It So Important Before an Extension?

Here's the thing: your extension might impact your drainage system in ways you haven't considered. Here's why checking your manhole chamber is vital:

• Location, Location, Location: Your extension's foundations or new walls could end up covering or obstructing access to your manhole chamber. Imagine trying to fix a blocked drain when you can't even get to the inspection point! Relocating a manhole is a complex and costly job, so it's best to plan for it upfront.

• Capacity Concerns: Will your existing drainage system be able to handle the increased load from your extension? More bathrooms, a bigger kitchen – these all mean more water flowing through your pipes. An inspection can reveal if your drains are adequate or if they need upgrading to prevent overflows and backups.

• Condition Check: Older drains can be prone to cracks, leaks, and other damage. Building work can exacerbate these issues. A pre-extension inspection can identify any existing problems and allow you to address them before they become major headaches (and before they're buried under your new extension!).

• Building Regulations: In many cases, building regulations require you to demonstrate that your drainage system is adequate for your proposed extension. A professional drainage survey, including an inspection of your manhole chamber, might be necessary to obtain planning permission or building control approval.

• Private vs. Public Sewers: This is a crucial point. Is your drainage system connected to a private sewer (your responsibility) or a public sewer (maintained by the water authority)? This distinction impacts what you can do and who's responsible for what. If your extension work affects a public sewer, you must get permission from your water authority before starting any work. They may have specific requirements and restrictions. If it's a private sewer, you have more flexibility, but it's still vital to ensure it's up to the task and complies with regulations.

  • Options: If your extension impacts a public sewer, you'll likely need to apply for a "build over agreement" or similar from your water authority. This involves submitting plans and demonstrating that your work won't damage or impede access to the sewer. For private sewers, you have more control, but you'll still need to ensure compliance with building regulations and potentially engage a drainage specialist to design any necessary modifications or upgrades.

• Preventing Future Problems: By checking your manhole chamber before you build, you're essentially future-proofing your extension. You're identifying potential issues early on, saving yourself time, money, and stress in the long run. Imagine having to dig up your new patio or flooring to fix a drainage problem – a nightmare scenario that can be easily avoided with a bit of foresight.

  
  

What Should You Do?

1. Locate your manhole chamber(s): They're usually circular or rectangular covers in your garden, driveway, or sometimes even inside your property.

2. Inspect the chamber (if safe to do so): Look for any signs of damage, blockages, or overflowing. Be cautious and avoid entering the chamber yourself unless you're a trained professional.

3. Determine if it's a private or public sewer: Contact your local water authority if you are unsure. This is essential before proceeding.

4. Consider a professional drainage survey: For a thorough assessment, it's best to call in a drainage specialist. They have the expertise and equipment to carry out a comprehensive survey, including CCTV inspections of your drains.

5. Plan ahead: If any issues are identified, work with your builder and drainage specialist to develop a plan of action. This might involve relocating the manhole, upgrading the drainage system, or carrying out repairs. If a public sewer is involved, contact the water authority immediately.

   
   

Don't let a small oversight turn into a major drainage disaster. Checking your manhole inspection chamber before you start your extension is a small investment that can pay off big time. It's all part of building smarter, not harder, and ensuring your extension is a smooth and successful project from start to finish. After all, you want your new space to be a source of joy, not a drain on your resources (pun intended!).

If you are thinking of starting an extension you can book a complimentary Discovery Call.

Kind regards,

Dan Hulbert

Builder | Consultant | Developer