Controlled ventilation helps reduce condensation and damp, by letting fresh air in when needed. However, draughts are uncontrolled: they let in too much cold air and waste too much heat.
To draught-proof your home you should block up unwanted gaps that let cold air in and warm air out. Saving warm air means you’ll use less energy to heat your home, so you'll save money as well as making your home snug and pleasant.
Draught-proofing around windows and doors could save you around £25 per year. Draught-free homes are comfortable at lower temperatures – so you may be able to turn down your thermostat saving even more on your energy bills.
Draughts happen where there are unwanted gaps in the construction of your home, and where openings are left uncovered.
You’ll find draughts at any accidental gap in your home that leads outside, such as:
You should block most of these – but be careful in areas that need good ventilation, such as:
If you’re happy carrying out simple DIY tasks, draught-proofing will be no problem. However, some homes, especially older homes with single glazing, will be more difficult to draught-proof. Professional draught-proofing is likely to save more energy because the installer will know exactly the right materials to use and where to use them.
There are plenty of DIY stores that sell draught-proofing materials, but look for draught-proofing with a Kitemark – this shows that the product is made to a good standard. British Standard Institution accredited products have a 20-year life when correctly installed and maintained.
For windows that open, buy draught-proofing strips to stick around the window frame and fill the gap between the window and the frame. There are two types:
Make sure the strip is the right size to fill the gap in your window. If the strip is too big it will get crushed and you may not be able to close the window. If it's too small there will still be a gap.
For sliding sash windows, foam strips do not work well. It’s best to fit brush strips or consult a professional. For windows that don't open, use a silicone sealant.
Draught-proofing outside doors can save a lot of heat and will only cost you a few pounds. There are four main things to consider.
Inside doors need draught-proofing if they lead to a room you don’t normally heat, such as your spare room or kitchen. Keep those doors closed to stop the cold air from moving into the rest of the house. If there is a gap at the bottom of the door, block it with a draught excluder – you can make one stuffed with used plastic bags or bits of spare material.
Inside doors between two heated rooms don’t need draught-proofing, as you don’t lose energy when warm air circulates.
If you don’t use your fireplace, your chimney is probably a source of unnecessary draughts. There are two main ways to draught-proof a chimney:
Remember to remove the draught-proofing if you decide to light a fire!
You can block cracks by squirting filler into the gaps. Floorboards and skirting boards often contract, expand or move slightly with everyday use, so you should use a filler that can tolerate movement – these are usually silicone-based. Look for the following:
Fillers come in different colours, and for indoor and outdoor use. They block gaps permanently so be careful when you apply them – wipe off any excess with a damp cloth before it dries. Fillers may break down over time, but can easily be reapplied.
Check whether you also need to insulate between the skirting board and the floor.
Hot air rises and gets lost into the cold space in your loft or attic, so it’s worth blocking off draughts around your loft hatch. Use strip insulation, as you would on a door.
You can fill small gaps around pipework with silicone fillers, similar to the fillers used for skirting boards and floorboards. Fill larger gaps with expanding polyurethane foam. This is sprayed into the gap, expands as it dries, and sets hard.
Old fan outlets may need to be filled with bricks or concrete blocks and sealed from both the inside and outside.
You can fill in cracks using cements or hard-setting fillers, but if it’s a large crack there may be something wrong with your wall. Consult a surveyor or builder to see what caused the crack in the first place.
Air needs to flow in and out of your house so it stays fresh, dry and healthy. Make sure you don’t block or seal any intentional ventilation, such as the following: