How Do I Prevent Leaks or Condensation in Skylights?
Skylights are a brilliant way to add natural light and style to your home, but no one wants to deal with water leaks or indoor condensation. You’ve probably searched things like:
“Why is my skylight leaking?”
“How do I stop condensation on rooflights?”
“Do frameless rooflights leak less than framed?”
In this guide, we’ll explain how to avoid common skylight issues, what causes leaks or fogging, and how frameless rooflights from Skylights.co.uk are designed to address these challenges effectively.
Table of Contents
What Causes Skylight Leaks?
Leaks aren’t always about the skylight itself — they’re often a result of installation mistakes or poor surrounding details.
Common leak causes:
Improper kerb or upstand construction
Sealant failures at joints or flashing
Cracked or aged glazing seals
Condensation mistaken for leaks
How to prevent leaks:
Use high-quality, factory-sealed skylights like frameless models from Regal Glass Group
Ensure correct installation with an insulated and waterproofed kerb
Always follow manufacturer's installation guides and UK Building Regulations
Choose units with integrated perimeter drainage (frameless models often include this)
“In over a decade of fitting skylights, most leaks I’ve seen come from poorly built upstands — not the rooflights themselves.”
— Alan Pierce, Installer, Bristol
Understanding Condensation in Skylights
Condensation occurs when warm indoor air meets cold glazing, creating moisture on the inside of your skylight. It’s common in:
Bathrooms and kitchens
Poorly ventilated flat roof extensions
Cold weather seasons
How to reduce condensation:
Use triple glazing or low-emissivity glass (e.g. from Skylights.co.uk)
Ensure mechanical or passive ventilation (like extractor fans)
Choose skylights with thermally broken frames to reduce thermal bridging
Keep interior humidity levels in check (especially during cooking or bathing)
“We had constant fogging in our old bathroom skylight. Since replacing it with a frameless triple-glazed rooflight from Skylights.co.uk, the condensation is gone.”
— Marion, homeowner in Newcastle
Frameless vs Framed: Which Resists Leaks and Condensation Better?
| Feature | Frameless Rooflights (Skylights.co.uk) | Traditional Framed Rooflights |
|---|---|---|
| Leak Resistance | ✅ High — minimal joins, sealed edge-to-edge | ❌ More frame joints to seal |
| Condensation Prevention | ✅ Excellent with thermal breaks & low-E glass | ❌ More prone in winter |
| Maintenance Requirements | ✅ Low (no hinges or opening components) | ❌ Hinges & seals wear over time |
| Installation Simplicity | ✅ Designed for flat/low-pitch roofs | ❌ More flashing complexity |
FAQs: Preventing Skylight Leaks & Fogging
No — they often leak less because they have fewer exposed joints and cleaner sealing methods.
Yes, over time, excess moisture can lead to mould, rot, or plaster damage. Proper ventilation and triple glazing are the best defence.
A frameless fixed rooflight with triple glazing from Skylights.co.uk — combined with a good extractor fan — keeps moisture at bay.
Fixed skylights are less likely to leak as they have no moving parts. If you need airflow, ensure that openers are high-quality and properly flashed.
Expert Advice
“When you combine the right product with good installation, condensation and leaks just don’t happen. Frameless skylights are fantastic for that.”
— Amira Patel, Architect, London
“With thermal breaks and triple-glazing, Skylights.co.uk rooflights outperform older framed models in leak resistance and insulation.”
— James Taylor, Rooflight Consultant
Regulatory Considerations
When preventing leaks and condensation, you must meet the following UK Building Regulations standards:
Part L – Thermal insulation (U-values under 1.2 W/m²K recommended)
Part F – Ventilation in wet rooms
Part C – Protection from moisture ingress and condensation
Reliable sources:
Support Resources & How-To Videos
Best Practice for Leak-Free Skylights
✅ Choose frameless fixed rooflights for flat roofs
✅ Triple glazing with solar/low-E coating
✅ Thermally broken kerbs and proper insulation
✅ Mechanical ventilation where needed
✅ Follow installation instructions to the letter
Frameless skylights from Skylights.co.uk deliver dependable performance with minimal maintenance, making them perfect for kitchens, bathrooms, and modern extensions.
