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
Featured articles and news
Professional practical experience for Architects in training
The long process to transform the nature of education and professional practical experience in the Architecture profession following recent reports.
A people-first approach to retrofit
Moving away from the destructive paradigm of fabric-first.
International Electrician Day, 10 June 2025
Celebrating the role of electrical engineers from André-Marie Amperè, today and for the future.
New guide for clients launched at Houses of Parliament
'There has never been a more important time for clients to step up and ...ask the right questions'
The impact of recycled slate tiles
Innovation across the decades.
EPC changes for existing buildings
Changes and their context as the new RdSAP methodology comes into use from 15 June.
Skills England publishes Sector skills needs assessments
Priority areas relating to the built environment highlighted and described in brief.
BSRIA HVAC Market Watch - May 2025 Edition
Heat Pump Market Outlook: Policy, Performance & Refrigerant Trends for 2025–2028.
Committing to EDI in construction with CIOB
Built Environment professional bodies deepen commitment to EDI with two new signatories: CIAT and CICES.
Government Grenfell progress report at a glance
Line by line recomendation overview, with links to more details.
An engaging and lively review of his professional life.
Sustainable heating for listed buildings
A problem that needs to be approached intelligently.
50th Golden anniversary ECA Edmundson apprentice award
Deadline for entries has been extended to Friday 27 June, so don't miss out!
CIAT at the London Festival of Architecture
Designing for Everyone: Breaking Barriers in Inclusive Architecture.
Mixed reactions to apprenticeship and skills reform 2025
A 'welcome shift' for some and a 'backwards step' for others.