Service
Loft Condensation & Roof Ventilation
Water dripping off the felt or rusty nails in the loft? That's almost always condensation, not a leak — and it ruins insulation and timbers if left.
- Eaves vent strips & soffit vents
- Ridge vents & tile vents
- Bathroom extract duct relocation
- Insulation crush-back from eaves
- Vapour-permeable underlay advice
- Photo evidence of moisture source
How loft condensation actually forms
Warm moist air from bathrooms, kitchens and bedrooms rises into the loft through ceiling gaps. When it hits the cold underside of the felt, it condenses — soaking insulation and rotting battens. The fix is airflow, not patching.
What proper ventilation looks like
Continuous eaves ventilation either side (10mm or 25mm strip depending on pitch) plus high-level venting (ridge or tile vents) so air actually moves through. Most older Buckinghamshire lofts have neither.
FAQs
How do I know it's condensation and not a leak?+
Condensation is evenly spread, worst on north-facing slopes, and dries up in summer. Leaks track to one spot, get worse in heavy rain, and don't care what time of year it is.
Is breathable felt enough on its own?+
On its own, no — BS 5250 still requires high- and low-level ventilation even with vapour-permeable underlay. We add eaves and tile vents as standard on reroofs.
Need Roofing Work You Can Rely On?
Speak with Butler Bespoke Roofing for honest advice, a free site visit and a clear, written quote anywhere across Buckinghamshire.