How to Draught Proof Doors and Windows
Draught Proofing Your Doors and Windows
Draughts account for quite a large proportion of the heat lost from your home and are also responsible for a good deal of discomfort. It is therefore worth spending a little money and effort to exclude them from your home. Locate draughts by running the flat of your hand along likely gaps. If you dampen your skin, it will enhance its sensitivity to the cold draughts. Otherwise, wait for a very windy day to conduct your search.
- Power drill
- Wood bits
Filling the Gap Beneath the Door
If the gap between the door and floor is very large, it is hound to admit fierce draughts, so it pays to use a threshold excluder to seal the gap. If you fit an excluder to an exterior door, make sure it is suitable; and if you can’t buy an excluder that fits the opening exactly, cut a longer one down to size.
The simplest form of threshold excluder is a flexible strip of plastic or rubber that sweeps against the floorcovering to form a seal. The most basic versions are self-strips that are simply pressed along the bottom of the door, but other types have a rigid-plastic or aluminium extrusion screwed to the door to hold the strip in contact with the floor.
This kind of excluder is rarely suitable for exterior doors and quickly wears out. However, it is inexpensive and easy to fit. Most types work best over smooth flooring.
A long nylon-bristle brush set into either a metal or plastic extrusion can be used to exclude draughts under doors. This kind of excluder is suitable for slightly uneven or textured floorcoverings, and can be fitted to hinged or sliding doors.
The plastic strip and its extruded clip are spring-loaded, so they lift from the floor as the door is opened. When you close the door, the excluder is pressed against the floor by a stop screwed to the doorframe. Suitable for both interior and exterior doors, automatic excluders inflict little wear on floorcoverings.
The aluminium extrusion with its arched vinyl insert presses against the bottom edge of the door. As it has to be nailed or screwed to the floor, it is difficult to use a flexible-arch excluder on a solid-concrete floor. If you plan to fit one on an external door, buy a version that has additional underseals to prevent rain from seeping beneath it. You may have to plane the bottom of the door.
The best solution for an exterior door is a kit combining an aluminium weather trim designed to shed rainwater, which is fitted to the door, and a weather bar with a tubular rubber or plastic draught excluder for screwing to the threshold.
Sealing Around the Door
A well-fitting door requires a gap of 2mm (1/16in) at top and sides so that it can be operated smoothly. However, a gap this large loses a great deal of heat. There are several ways to seal it, some of which are described here. The cheaper excluders have to be renewed regularly.
From Top of Door to Bottom:
Stick-on foam strips
The most straightforward excluder is a self-foamed-plastic strip, which you stick around the rebate: the strip is compressed by the door, forming a seal. The cheapest polyurethane foam will he good for one or two seasons (although it’s useless if painted), but is suitable for interior doors only. The better-quality vinyl-coated polyurethane, rubber or PVC foams are more durable and do not perish on exposure to sunlight, as their cheaper counterparts do. Don’t stretch foam excluders when applying them, as that reduces their efficiency. The door may be difficult to close at first, but the excluder will adjust after a short period of use.
A small vinyl tube held in a plastic or metal extrusion compresses to fill the gap around the door. The cheapest versions have an integrally moulded flange, which can be stapled to the doorframe, but they are not as neat.
Thin metal or plastic strips that have a sprung leaf are either pinned or glued to the doorframe. The top and closing edges of the door brush past the sprung leaf, sealing the gap, while the binged edge compresses a leaf on that side of the door. This type of draught excluder cannot cope with uneven surfaces unless a foam strip is incorporated on the flexible leaf.
A variation on the sprung strip, the leaf is bent right back to form a V-shape. The strip can be mounted to fill the gap around the door or attached to the door stop so that the door closes against it. Most types are cheap and unobtrusive.
You can effectively seal gaps with a bead of flexible sealant squeezed onto the door stop; a low- tack tape is applied to the surface of the door to act as a release agent. As the door is closed, it flattens the head, filling the gap perfectly. When the sealant has set, the parting layer of tape is peeled from the door.
You can also buy flexible tubing for bonding with sealant to compensate for movement.
Draught Proofing Keyholes and Letterboxes
Make sure the external keyhole for a mortise lock is fitted with a pivoting coverplate to seal out draughts during the winter.
You can buy a hinged flap thatonto the inner side of the door to cover a letter box. Some types have a brush seal mounted behind the flap to reduce draughts.
Sealing Up Draughty Windows
Because they can affect every room in the house, draughty windows waste even more heat than a badly fitting door. As part of an energy-saving scheme, it is imperative to seal at least the worst offenders with effective draught excluders.
The top and bottom closing rails of a sash window can be sealed with any form of compressible excluder. The sliding edges usually admit fewer draughts, but they can be sealed with a brush seal fixed to the frame inside for the lower sash, outside for the top one. A springy V-strip or a compressible plastic strip can be used to seal the gap between the sloping faces of the central meeting rails of a traditional sash window. For square rails, use a blade seal.
Sealing a pivot window
When you close a pivot window, the movable frame comes to rest against fixed stops. Fitting excluders to these stops will seal off the worst of the draughts. You can use compressible spring or V-strip draughtproofing,or a good-quality flexible-tube strip, so long as they are weatherproof.
Filling large gaps
Large gaps left around newly fitted window frames (and doorframes) will be a source of draughts. Use an expanding-foamto seal these gaps. When the has set, repoint the masonry on the outside.