Draughtproofing is one of the cheapest and easiest ways to save energy in any type of building. It should be fitted to:
- doors (Including letterboxes and keyholes)
- chimneys and fireplaces
- floorboards and skirting boards
- loft hatches
- pipework (leading outside)
- damaged walls
The Energy Saving Trust estimates that draughtproofing can generate fuel bill savings of between £25 and £50 every year.
Windows: For windows, there are 2 main types of material:
- self-adhesive foam strips – the cheapest option, and easy to install, however may not last as long as other methods
- metal or plastic strips with brushes or wipers attached – these are long- lasting, but cost more
Make sure the strip is the right size to fill the gap in the window. If the strip is too big it will get compressed and damaged and it may be difficult to close the window. If it’s too small there will still be a gap.
For sliding sash windows, it’s best to fit brush strips or consult a professional. Foam strips do not work well.
For metal-framed windows or windows that don’t open, a silicone or sealant can be used.
Doors: Gaps under and around external doors, letterboxes and keyholes can all cause draughts:
- fit brushes or hinged flat draught excluders at the bottom of the door
- fit draughtproofing strips (foam or brush) around the door frame
- fit a purpose-made cover for the keyhole
- use a letterbox flap or fit a letterbox brush
Internal doors need draughtproofing if they lead to a room not normally heated, like the spare room or kitchen. Keep doors to unheated rooms closed as much as possible to stop the cold air from moving into the rest of the house.
Internal doors between two heated rooms don’t need draughtproofing – it can be useful to let warm air circulate between different rooms.
Chimneys and fireplaces: If the fireplace is unused, the chimney is probably a big source of unnecessary draughts.
There are 2 main ways to draughtproof a chimney:
- have a cap fitted over the chimney pot
- use a chimney balloon – an inflatable cushion which blocks up the chimney and can remain in place until the fire is next lit
Floorboards and skirting boards: block cracks using filler.
Floorboards and skirting boards often contract, expand or move slightly with everyday use, so a filler that can tolerate movement should be used – these are usually silicone-based.
Fillers block gaps permanently so be careful when applying them and wipe off any excess or mess with a damp cloth before it dries. Fillers may break down over time, but can easily be re-applied.
Loft hatches: Draughtproofing the loft hatch is essential, since hot air rises and is lost into the cold space in the loft.
Cold air can also blow in through the gaps around the loft hatch. Loft hatches can be draughtproofed by using strip insulation, similar to that used on doors.
Which rooms don’t need draughtproofing?
Be careful about draughtproofing rooms that need good ventilation, including:
- areas where there are open fires or open flues – It is essential that areas like this have adequate
- rooms where a lot of moisture is produced, such as the kitchen, bathroom or utility Good ventilation helps reduce condensation and damp.
Other areas that might cause heat loss include:-
- pipework (leading outside) – use expanding polyurethane foam, filler or silicone mastic
- damaged walls – use a hard-setting wall filler or cement (but if cracks reappear it may be best to consult a surveyor)
- unused vents and fans – these can be blocked up
Never block boiler flues, air bricks or trickle vents – adequate ventilation is absolutely essential.
Draughtproofing products and installers
For a list of registered installers see the National Insulation Installers website – http://www.nationalinsulationassociation.org.uk/
For additional information on products, installers and manufacturers, see the NIA website http://www.nia-uk.org