How to totally draught-proof your doors
Save on your energy bills by banishing the wind whistling through your doors - learn how to install weatherstripping, fit a draught excluder, draught-proof your letterbox and more!
With fuel bills on the rise, we're all keen to save energy by keeping much heat as possible in your home, so it’s essential to ensure your doors and windows are properly draught-proofed to prevent warmth from escaping and chilly air from entering your rooms.
Draught-proofing is one of the cheapest and most effective ways to save energy and money in a home. The best thing to optimise your draught and weatherproofing is to ensure your door is fitted correctly by using recognised installers. High-quality and expertly fitted doors won’t suffer from gaps which cause draughts.
The worst culprits for letting in draughts are the front door, especially if it has a letterbox fitted, and the back door. However, remedying the problem is usually quite straightforward and inexpensive. Read on to find out how to draught-proof a home using simple solutions that even a novice DIYer can manage. And complete your draught insulation with our tips on draught-proofing windows.
How to fit self-adhesive weatherstripping
Gaps between the door and the door frame can cause draughts to whistle into your home, but self-adhesive weatherstripping is an affordable way to fill the gap and block the draughts. It has the added bonus of cushioning the closing mechanism to soften slamming.
Weatherstrips come in a variety of materials, including felt, foam, rubber and vinyl. These vary in longevity and price, but your choice will be mostly based on your preferred look and budget. Some types of weatherstrip edging also double up as an acoustic seal. This type is a great option if you live on a noisy street and you want to turn the volume down on external sounds as well as cut draughts.
You will need:
- Self-adhesive weatherstripping
- Soapy water
- Lint-free cloth
- Measuring tape
- Step 1: The strip should be fitted on the inside of the door frame and needs to be tightly compressed when the door is closed. The strips come in a variety of thicknesses - choose the thickest option that doesn’t prevent your door from fully closing.
- Step 2: If you’re re-installing weatherstripping, remove the old strips and any leftover adhesive with oil or a specific adhesive remover. Clean around the door frame with mild soap and water to remove any grease that might prevent the new weatherstrip from sticking. Thoroughly dry any surface you’ve cleaned before applying the new strip.
- Step 3: Measure the length of one side of the door frame and cut the weatherstrip to size, preferably in one length. It’s better to cut it a little too long and trim down afterwards, because you want to get it right into the corners. Peel away the backing and press the weatherstrip into place. Repeat around all sides of the door frame.
TOP TIP: You can also apply the strips around the outer edge of the frame where it meets the recess or wall, and any other cracks or corners that could be letting cold air through. If you're not sure exactly where the draught is coming from, pass a lit incense stick or candle around the window. Anywhere the smoke or flame is blown is a problem area.
To check if you have a draught coming through your door, run your hand around the edge of the door frame. If you can feel cold air coming through, adjust the latch or hinges to get a better fit of the door in the frame.
How to fit a door brush strip draught excluder
The space at the bottom of a door, where it glides over the floor, is the main culprit for draughts on both internal and external doors. If there’s a gap under the door then you can fit a brush seal or hinged flap at the bottom of the door.
You will need:
- Tape measure
- Brush strip draught excluder
- Sharp utility knife
- Step 1: Before you buy your brush strip draught excluder, measure the width of the door to make sure you’re getting the right minimum size.
- Step 2: Before fitting, cut the strip to the exact length of the door with a sharp utility knife to ensure there are no gaps.
- Step 3: Position the brush so that it lightly sweeps the floor when the door is opened. If it’s positioned too low down then the door won’t open easily. If you leave too big a gap then you’ll still get draughts.
- Step 4: Some brush strips come with an adhesive backing, but you should still screw or nail it into place to make sure it won’t detach over time.
As an alternative to a brush strip draught excluder, you could choose to fit a hinged flap design (sometimes known as weather bar) to eliminate draughts at the bottom of your door. This works in a similar way to a brush strip. Instead of bristles, it has a solid rubber panel which hinges and moves as the door opens and closes. Bear in mind that the way your door opens will make a difference to which draught excluder is best. For instance, hinged flap designs are only suitable for doors that open inwards as they won’t be able to travel over the door frame.
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We recommend starting with the space at the bottom of your doors. Try fitting a hinged flap or brush seal. Mohair seals are usually the best option, as mohair is excellent at stopping air currents in their tracks. If your door swings inwards, fit the seal or flap on the inside bottom edge. If it swings outwards, fit it to the outside bottom edge.
How to fit a draught-proof letterbox flap
Letterboxes can often be the culprits for letting draughts into your home. An energy-efficient letterbox will have brushes and a flap that work together to stop air from blowing through into your home and prevent heat from escaping. Many letterboxes are missing one of these elements, but energy-efficient ones are affordable and easy to fit.
If you’re going to upgrade your letterbox then you’re most likely going to replace the whole internal faceplate. Always take accurate measurements of your door so that the new letterbox fits correctly. Bear in mind you may need to trim the letterbox hole.
Letterboxes come in a host of different finishes and colours, including brass, aluminium and plastic. Some materials have better thermal efficiency credentials than others, for example a basic metal flap with no brushes will always feel cold.
You could also remove your letterbox altogether and install a standalone letterbox outside your house. If you have a timber door, consider filling the gap where the letterbox would be with an appropriately-sized piece of wood. Plane or sand the timber down to fit, treat any blemishes with wood filler, then paint or stain it to match the rest of the door finish.
How to cover your door's keyhole
Although a keyhole is a small gap in your door, it could still be letting in unwanted cold air. There are several remedies for this. A simple metal disc, known as a covered escutcheon, can be screwed to the outside of the door and pushed to the side when you’re using the key.
You can also get keyhole lock cover guards, which are designed for modern cylinder locks. These flaps fit snugly over the face of the cylinder (where you put your key in) and can just be lifted up to use the lock.
Similarly to letterboxes, you can also get brush draught excluders for keyholes, where the key can be pushed through the brushes to operate the lock.
Finally, if your door has an old lock that you no longer use, fill the obsolete keyhole with wood filler to stop draughts from entering.
Add a soft pillow draught excluder
One of the easiest and most affordable ways to block out draughts is to lay a long soft cushion or bolster on the floor, directly in front of the door. There are plenty of attractive designs available in a range of patterns to match your existing décor.
Some designs feature buttons or fixings to attach them to the door, however most soft cushion excluders are simply placed up against the door once it’s closed. But bear in mind that the draught excluder won’t be in position when you’re out of the house, so the gap at the bottom of your front door can still allow heat to leak out and cold air to come in. For this reason, a soft pillow draught excluder is really best used for internal doors rather than your front door. See our favourite stylish draught excluders here.
A more effective way to improve insulation and to prevent draught from whistling into your hallway is to install heavy curtains with a thermal lining onto the interior of the door. Alternatively, you can add a hook-on thermal lining to an existing door curtain. These are an affordable solution and readily available from high street stores such as Dunelm. Check out our guide to thermal blinds for more on how thermal technology reduces heat loss.
How to draught-proof patio doors
Doors and windows are the thermal weak-points of any home, and this is especially so in the case of patio doors. Whether it’s of the bi-fold, French or sliding variety, a patio door presents the elements with plenty of gaps to creep through, and the warmth inside your home with plenty of glass through which to escape.
However, there are steps you can take to limit this:
Double-glazed glass tends to be less thermally conductive than the frame into which it’s built. Therefore, doors which incorporate lots of double-glazing tend to be more thermally efficient than you might expect. If it’s triple-glazed glass, then this is especially so. But remember, double-glazing does have a finite lifespan. If you can see condensation forming between the panels, it indicates that the seal has failed and that all of the inert, insulating gas has rushed out. If that’s the case, you might need to replace the glass insert or even the entire door. You also need to make sure that moisture and wind can’t rush through the cracks around the edges.
If the door is a sliding or bi-fold door, then it might have become unseated from its rail, which will cause the gaps around the edges to grow. Check the track for small stones and other obstructions, and run a vacuum cleaner along the bottom of the track to pick up all of those stray dust particles. For best results, spray the track with WD40 and slide the door back and forth a few times to ensure that the lubricant is evenly distributed. If necessary, re-seat the door.
Outward-opening French doors will benefit from having their weatherstripping replaced. Over time, thousands of compressions will take their toll on the elasticity of the weatherstripping. This means that it won’t expand to the same size, and thus it won’t form a tight seal around the edge of the door. By replacing the weatherstripping, you’ll vastly improve the door’s draught-excluding abilities
Sliding patio doors can’t use compressible weatherstrip seals, as they need to be able to move back and forth. Instead, brush-style seals are the best solution for sliding doors. These, too, will benefit from being replaced from time to time.
How to draught-proof bifold doors
Insufficient weatherstripping around bi-fold doors leads to draughts and poor insulation. Check to see if any of the strips have come loose or fallen off completely. You might also want help from someone else to hold up each panel as you tighten down the screws again. Make sure your bi-fold doors aren’t sagging as this can also be a reason for draughts to be filtering through.
Now your doors are sorted, do you still need to draught-proof your windows? Find out how to draught-proof windows here. And explore all our energy-efficiency content to save on your usage and your bills.
Anna-Lisa De’Ath is a freelance magazine editor and journalist specialising in homes & interiors, gardening and crafts