Pitched roofs have a sloped surface, allowing water to flow off them freely. In contrast, flat roofs are flat in appearance with a very low pitch. While this makes them less expensive and quicker to install, they can also become vulnerable to damage without the right drainage.

In this short post, we discuss water drainage on flat roofs and how to avoid any problems on your property.

Drainage is paramount

While a bit of surface water might not seem like the biggest issue, it can easily develop into a number of problems:

  • Increase of load, putting excess pressure on parts of the roof
  • Holding moisture on the roof, leading to decay of roofing materials
  • Water ingress, causing damage to the roof’s structure and potentially the rest of your property

So, what are the must-haves when it comes to flat roof drainage?

Flat roof falls and drainage

One misconception with flat roofs is that they should be completely flat. To clear surface water efficiently, they should actually have a small slope. British Standards BS6229 and BS8217 outline that flat roofs should have 6minimum ‘falls’ of 1:40 – sloping down 2.5cm for every metre the roof covers.

Flat roofs also need sufficient drainage. This can be achieved by external guttering or internal downpipes and outlets. External guttering is used on all properties to guide water down the drains as it runs off the roof.

If water is not flowing directly off a flat roof, internal drainage can guide water off the roof through pipes to the main drainage system. It’s recommended that all flat roofs have at least two drainage points.

Let’s talk

Need more assistance with your flat roof? DPR Roofing in Huddersfield can help. We’re a team of roofing specialists with nearly three decades of experience in the industry. Our flat roofing services cover everything from inspection and repairs to guttering and replacement, so you can rely on us for any flat roofing issues.

Need More Help?

For expert help and advice or for a more accurate quote speak to our friendly team today.

Call us on 01484 866 772