New Build Flat Roof and Roof Lanterns Fixed
Even with a newly built property, things are not always finished to the standard you would expect. We were recently called to a new build home in Swansea where a rear flat roof extension had been fitted with two roof lanterns, but the installation had been done incorrectly. The result was poor water run off and a high risk of leaks.
After inspecting the roof, it was clear that the roof lanterns had been installed too low and the pitch of the flat roof was wrong. A flat roof should never be completely flat. It needs a designed fall so rainwater can drain away properly. When the fall is inadequate, water can sit on the surface and eventually find its way into vulnerable points around edges, joints, and roof lantern upstands.
What was wrong with the original installation?
The main issues we found were:
- Roof lanterns installed too low, making proper waterproofing and upstands difficult
- Incorrect pitch across the roof, which caused water to sit rather than drain
- Increased risk of ponding water, leading to potential leaks and premature roof failure
On a roof with lanterns, correct height and detailing is essential. If the lantern kerbs are too low, you can struggle to achieve the correct waterproofing height and water can be directed back towards the lantern rather than away from it.
Our solution and the work carried out
To fix the problem properly, we needed to strip the roof back and rebuild the levels correctly. The work included:
- Carefully removing the two roof lanterns for safe reinstallation
- Removing the existing roof covering to expose the roof deck
- Building the roof surface up slightly to create the correct fall
- Raising the roof lanterns to the correct height
- Re roofing the extension using Firestone RubberCover EPDM
Why we used Firestone RubberCover EPDM
For this type of flat roof in Swansea, Firestone RubberCover is a strong choice because it is:
- Durable and long lasting
- UV resistant and suitable for the UK climate
- Installed in a way that helps reduce weak points, which is ideal around roof lanterns
- Excellent when combined with correct falls so water runs off as designed
The key point is that even the best flat roofing system will not perform properly if the roof does not have the right pitch. By adjusting the roof surface first, we ensured the membrane could do its job.
Please get in touch if you would like a free no obligation quote for your project.
