Ventilation
Subfloor ventilation
Restoring effective airflow beneath suspended timber floors to reduce moisture and decay risk.
What the issue is
Suspended timber floors rely on cross ventilation through air bricks to keep the void and timbers dry. Blocked or missing vents raise the risk of decay and musty odours.
Common symptoms
- Musty smell at floor level
- Springy or soft floorboards
- Damp skirtings
- Visible fungal growth in the void
- Cold, damp ground floor
Likely contributing factors
- Blocked, painted over or buried air bricks
- Insufficient number of vents
- Debris or oversite rubble in the void
- Raised external ground levels
- Standing water beneath the floor
Conditions that may be mistaken for it
- Rising damp in adjacent walls
- A plumbing leak beneath the floor
- Condensation at floor level
How the issue should be investigated
- Locate and count existing air bricks
- Inspect the void where access allows
- Check for debris, water and decay
- Assess external ground levels
Potential treatment or repair options
- Clearing and reinstating air bricks
- Installing additional vents or periscope vents
- Clearing void debris
- Lowering external ground levels
- Timber repairs where decay is present
When treatment may not be appropriate
- Where existing ventilation is adequate and dry
- Where a leak is the actual source
Factors affecting the cost
- Number of vents required
- Void access and clearance work
- External making good
- Any timber repairs identified
What to expect during an inspection
The surveyor will inspect available access points, count vents and assess the void where it can be reached safely.
Final recommendations always depend on the property, the inspection findings and the confirmed cause. Elevated readings alone do not confirm rising damp, not every mould problem requires extensive treatment, and damp-affected plaster does not always need replacing.
Frequently asked questions
Next step
Not sure which inspection you need? Start with a few questions.
Tell us what you are seeing and we will set out what is likely, what is uncertain and which inspection would answer the question. Speak to us on 0333 335 6152 if you would rather talk it through.