Condensation in the Loft
Water in the loft isn't always a leak. Condensation is common, especially after insulation upgrades.
Possible causes
- Poor roof ventilation
- Warm, moist air rising from the house
- Non-breathable underlay
- Insulation blocking eaves vents
Warning signs
- Droplets on the underside of the underlay
- Damp or mouldy timbers spread across the loft
- Worse on cold mornings rather than after rain
How it's usually fixed
- Adding eaves, ridge or tile vents
- Clearing blocked eaves
- Fitting breathable membrane when re-roofing
When to call a roofer
If you're not sure whether it's a leak or condensation, an inspection will tell you.
This page describes possible causes only. We can't diagnose your roof without inspecting it.