Most people think of soffits as just a neat panel under the roof edge. They also have a quieter job: letting air into the roof space. That air flow helps keep the loft dry and the timbers healthy.
What goes wrong without airflow
Everyday living puts a lot of moisture into the air, from cooking, bathing and drying clothes. Some of it rises into the loft. If it cannot escape, it condenses on cold surfaces, such as the underside of the roof covering and the timbers. Over time that can cause damp patches, mould, rusty nails and rot in the roof structure.
How soffit vents help
Vented soffits, or small vents in the soffit board, let fresh air enter at the eaves. It moves up through the roof space and out at the ridge or through other vents. This steady, gentle airflow carries moisture away. Vented strips or discs in UPVC soffits are a simple way to provide this.
Do not block them
Loft insulation pushed hard into the eaves can block the path of air. Boxes stored against the eaves can do the same. Keeping a gap, often with a small guide fitted at the eaves, lets the insulation sit in place without cutting off the airflow.
When fitting new soffits
Ask whether the new soffits will be vented, and where the air will exit. Replacing vented timber boards with solid ones, without any other ventilation, can create a problem that did not exist before. It is worth checking that the loft still breathes after the work.
Signs of poor ventilation
Condensation on the underside of the roof, mould on the timbers or damp insulation are warning signs.
For roofline work, see our UPVC Soffit and Fascia section or call us on 07766 547309.
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