🪟 Why Sub-Floor Ventilation Matters in Older Leigh Homes
If your home in Leigh was built before 1970, it likely has suspended timber floors. These floors rely on air bricks to keep the void below ventilated, dry and decay-free.
But if those vents are blocked, missing or bridged, moisture can build up under the floorboards — and that’s exactly when wet rot, dry rot or wood-boring beetles start to attack.
🚨 Common Signs of Poor Sub-Floor Ventilation
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Floorboards feel springy or soft
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A musty smell that never goes away
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Cold, damp air rising through the floor
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Visible decay on joist ends or wall plates
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Black mould at the base of internal walls
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Past infestation by common furniture beetle
💨 What Are Air Bricks and Why Do They Matter?
Air bricks are small, ventilated openings fitted into external walls at ground level. Their job is simple — to keep air moving through the underfloor void, which:
✅ Prevents condensation build-up
✅ Keeps humidity below 20% (ideal for timber health)
✅ Stops fungal growth like wet rot or dry rot
✅ Makes the floor less attractive to beetles like Anobium punctatum
✅ Maintains energy efficiency by avoiding damp insulation or joist rot
In Leigh, many older homes have bricked-over or painted air bricks, or they’re blocked by driveways, soil, or render — leading to trapped moisture beneath the floor.
🪵 What Happens When Floors Aren’t Ventilated?
Without fresh airflow, timber can reach the moisture threshold (20%+) needed for:
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Wet rot: Brown or black decay, often at joist ends
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Dry rot: Fast-spreading fungal decay inside voids
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Beetle infestation: Common furniture beetle and other wood-borers
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Salt staining: Caused by sub-floor damp rising into walls
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Structural weakening: Especially where timber touches walls or soil
🧱 How We Fix Sub-Floor Ventilation in Leigh Homes
At Weather Wise, we carry out full sub-floor ventilation checks as part of our timber and damp assessments.
We may recommend:
✅ Installing or upgrading air bricks to current regulations
✅ Removing render or soil that’s blocking airflow
✅ Fitting periscope vents or ducts if external access is limited
✅ Adding DMEV systems to reduce internal moisture levels
✅ Treating timber with preservatives where early decay is found
We make sure every suspended floor we inspect is dry, stable, and protected for the future.
📍 Why This Matters in Leigh
Many areas of Leigh (including Westleigh, Higher Folds and Atherleigh) are filled with:
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Pre-war red-brick homes with shallow voids
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Post-war council properties with bricked-in vents
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Extended kitchens with blocked off rear air flow
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Homes suffering repeat floor damp after laminate or vinyl installation
We understand the housing stock — and how to keep it healthy.
👷♂️ Why Choose Weather Wise
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✅ Level 3 certified in timber preservation
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✅ Full damp & ventilation inspections
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✅ Members of the Damp Proofing Association
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✅ Federation of Damp approved specialists
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✅ Trusted by homeowners across Leigh and Greater Manchester
📞 Book a Free Sub-Floor Ventilation Check in Leigh
https://weatherwiseuk.co.uk/pages/contact
FAQs
How many air bricks do I need?
It depends on the floor size and layout — but modern guidance suggests one air brick every 1.5–2m per side of the building.
Can I use plastic vents instead of clay ones?
Yes — modern plastic air bricks are more durable and less prone to clogging.
What if there’s no access under the floor?
We can create access points for inspection, and fit periscope-style vents to bring airflow under extensions or closed voids.