Ventilation
Sub-floor ventilation
Investigate and improve sub-floor airflow where trapped moisture threatens suspended timber floors.
Why diagnosis matters
Treat the cause, then repair the damage
Suspended timber needs a clear flow of air beneath it. Blocked air bricks, altered ground levels and sealed voids can allow humidity to build and support decay.
Technical review
Dan, Director / Surveyor
Last reviewed: July 2026. Advice is general until the property, access and visible evidence have been assessed.
Guarantee & aftercare
Written guarantee terms are matched to qualifying work, with inclusions, exclusions and aftercare explained before acceptance.
What we consider
Possible causes and lookalikes
Blocked or bridged vents
Insufficient opposing airflow
Leaks and ground moisture
Alterations that restrict the void
Inspection method
A clear work sequence
Step 1
Inspect accessible vents and voids
Step 2
Identify moisture source
Step 3
Clear or add ventilation where suitable
Step 4
Treat or repair timber only after source control
Scope boundaries
Honest about what the work does—and does not—cover
Access creation, drainage, structural timber replacement and hazardous voids are separately assessed or referred.
Common questions
About sub-floor ventilation
Can more air bricks solve rot?+
Ventilation may be part of the solution, but leaks, ground conditions and damaged timber also need assessment.
Do you lift floors?+
Opening-up is agreed separately because finishes, services and access risks vary.
Will you treat woodworm at the same time?+
Only where active infestation is supported and the treatment scope is agreed.
Related services
Continue your investigation
Next step
Claim your complimentary survey before choosing a treatment
Tell us what you can see, when it changes and where the property is. Photographs can help us triage the next step.