- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 10 Jul 2018
Draught proofing buildings
See also: Draughts in buildings.
A draught is a noticeable current of air inside a building that can make its occupants uncomfortable and result in unnecessary heat loss. Draught proofing, also known as draught exclusion, is a technique for controlling draughts. It can be an inexpensive and effective way of improving thermal comfort and energy efficiency.
The locations of draughts are easiest to identify on windy days, by wetting the back of a hand and passing it over the area most likely to be affected – around window frames, doors, pipes, etc. A building should be closely inspected for any unwanted gaps and uncovered openings to the exterior such as keyholes, letterboxes, chimneys, floorboards, skirting boards, loft hatches, fireplaces, wall cracks, fittings, and so on.
Draughts can also be caused by air falling rapidly when it comes into contact with a cold surface such as a window.
Single-glazed windows, particularly sash windows, can be prone to draughts. The most obvious method for draught proofing windows is to install double glazing. However, if this isn’t an option or is too expensive, there are more cost-effective alternatives:
- Window foam seal: A thick tape which is easy to apply. This isn’t the best method for sliding sash windows.
- Foam sealant: Can be sprayed into gaps around windows and doors.
- Metallic or plastic brush strips: More expensive than foam or tape but more durable.
- Cling film: A cling film sheet taped around a window, leaving a gap of a few millimetres, and heated with a hairdryer until taut. A cheap and simple solution although it may not be entirely affective.
- Fitting a weatherbar or door brush strip which act as a seal at the bottom of the closed door.
- Fitting a draught excluder to the bottom of the door or letterbox.
- Letterbox plates can prevent cold air entering.
- Keyhole covers can prevent cold air entering and slide out of the way of keys.
Draughts that are found in wall cracks can be prevented by filling the cracks with cement or hard-setting fillers. If cracks persistently appear in the same area they may require a professional to address the underlying problem.
Draughts from redundant extractor fans can be prevented by filling the fan outlet with bricks and/or concrete and then sealing it. Similarly, draughts from chimneys and fireplaces can be stopped by fitting a cap over the chimney pot or fitting a chimney draught excluder. Care must be taken not to completely seal chimneys, ad they need some ventilation to prevent moisture build up.
 Find out more
 Related articles on Designing Buildings Wiki
Featured articles and news
What U-values are, why they matter and how they are calculated.
The need to ensure that we plan for all aspects of our bio-economy
BSRIA calls on government to reach deeper into the causes of pollution.
George Demetri brings a whole new level of technical knowledge to Designing Buildings Wiki.
Quality professionals need to take an active role in driving the completion process forwards.
The innovations needed to move from rhetoric to realisation.
Creating a sense of place, with radically-low running costs and the highest comfort levels.
A conversation between David Mitchell and Caitlin DeSilvey.
A quick guide to brick sizes.
The Union Street development in Southwark was a passion, as well as a business endeavour.
Do our water quality standards demonstrate to the public that their supply is clean?
A third of practitioners do not have easy access to the knowledge they need.
Sustainable approaches to relief, recovery and reconstruction after a natural disaster.