Step by step
Choose suitable conditions
Test on a cool windy day with heating and fans in their normal state. Close external doors and windows without blocking required vents.
Check likely edges by hand
Move slowly around window frames, doors, loft hatches, floor edges and service penetrations. Look for movement of curtains and listen for whistles.
Use a safe indicator
A strip of tissue can reveal airflow. Avoid candles or smoke near curtains, combustible materials, alarms or gas appliances.
Match the remedy to the opening
Adjust catches, replace worn seals or use appropriate draught-proofing. Do not seal combustion-air vents, trickle vents required for moisture control or unknown openings.
Ready-to-use checklist
- Required vents identified
- Doors and windows checked
- Loft hatch and service gaps checked
- Safe airflow indicator used
- Seal type matches moving joint
- Moisture and combustion risks considered
Common problems
The draught is near a boiler or fire
Do not block it. Obtain competent advice because combustion appliances may require permanent ventilation.
Sealing makes condensation worse
Restore ventilation and address moisture generation and extraction; energy efficiency and indoor air quality must be balanced.