How to waterproof a rooflight

[edit] Introduction

There are many reasons why a rooflight might start leaking. It could be the result of an inadequate installation, or the rooflight may have been damaged after being exposed to high winds or suffering an impact. In some cases, a leak can even turn out to be not a leak at all, but a condensation problem.

Even a small leak can be a source of inconvenience for a building’s occupants, and it could damage expensive equipment or decorations. Problems such as damp and mould can also result from a leaking rooflight, leading to uncomfortable conditions and potential health hazards.

[edit] Methods for waterproofing rooflights

As with any type of building penetration, there are several ways to waterproof a rooflight, and the right choice will depend on the roof construction, as well as the finished appearance that you wish to achieve.

In residential buildings with pitched roofs, for example, rrooflight installations are typically sealed using flashings with tiles layered carefully over the top for a weatherproof finish.

However, this method will not work on most commercial buildings – particularly those with flat or low-pitched roofs and no roof tiles. So other techniques will be required. Although a waterproof rooflight can be achieved with materials such as EPDM rubber, or even traditional roofing felt, GRP is one of the best ways to ensure a leak-free result that will look good and last for many years with minimal maintenance.

[edit] Related articles on Designing Buildings

• Leaks in buildings.
• Damp.
• Roofing defects.
• Roofing repairs.
• Rooflight.