Ill-fitting doors and windows are the main sources of draughts, but other points of entry are via chimney flues and floors. Warning Beware of total draughtproofing if the room contains a fuel-burning appliance, unless it is a balanced flue type in which case it automatically draws its air from outside. For other appliances, particularly paraffin and bottled gas heaters, an air supply is needed. Either ignore the
draughts or, ideally, fit ventilator plates or air ducts close to the appliance so it can draw its air from outside, either straight through an outside wall, or indirectly from under the floor via the airbricks and an opening cut in the floorcovering.
With timber floors in ground floor rooms it is common to get draughts coming up between the boards and through the gaps between the floorboards and the skirtings. Do not be tempted to cure the problem by blocking air bricks — an underfloor air supply is vital to keep floor timbers in good condition.
First decide whether you want to insulate the floor, otherwise proceed as follows.
Obviously, fitted carpets are ideal for eliminating floor draughts, and if the carpet is taken a short distance up the skirting it will also effectively seal skirting draughts, as well as minimising accidental paint chips on the skirtings. Use an L-shape hardwood moulding to seal the exposed carpet edge.
Alternatively, seal floor-to-skirting cracks with a bead of non-setting mastic, which is available in white and brown. The mastic is sold in injector packs for application using a screw-down plunger or trigger-operated applicator gun.
If preferred, the gaps can be sealed by tacking scotia or quadrant timber moulding around the perimeter of the room. It is usually best to press the moulding against the floor and then glue and tack it to the skirting so that any movement between the floor and the skirting will not open up the easily seen moulding to skirting joint.
Where the floorboards will not be covered by a floorcovering, use papier mache to seal the gaps between the boards, or use timber laths if the gaps are more than about 4mm thick.
To prevent draughts coming down disused chimneys, make a cover for the fireplace opening. This can be a plywood, hardboard or composition board sheet tacked to a timber framework wedged in the fireplace opening. Cut a hole at least 100 x 50mm in the panel and fit a neat ventilator plate to provide gentle ventilation, which is essential to keep the flue dry.
Because doors are opened and closed frequently, hard-wearing draught excluders are required. For the sides and top of the door frame there are a variety of suitable types.
Sprung hard-plastic or metal strip is widely used. The strip is cut to length and nailed to the door frame with the raised edge facing towards the rebate (step) in the frame. As the door is closed it slides past the sprung strip which then rests against
the edge of the door forming a good seal. Remember to leave the lock plate clear.
Where there is room, an easier draught excluder to fit is self-adhesive soft rubber tape which simply presses into the rebate along the top and lock side of the frame, and on to the inside edge of the frame on the hinge side. To ensure good results, make sure the frame is thoroughly clean before fixing the tape.
For difficult-to-seal door frame gaps, a long-lasting solution is to use the slightly more costly rigid plastic or aluminium strips fitted with brush strips, or soft plastic or rubber beads of various designs. The strips are cut to length and simply nailed around the sides of the door frame with the sealing edge lightly pressed against the face of the door so that draughts are stopped, but the operation of the door is not impaired.
A commonly used draught excluder for under-door draughts is the stripbrush with a plastic or aluminium holder that screws along the bottom edge of the door. Others may have a flexible plastic or rubber blade, and some are sprung so that the flap lifts automatically when the door is opened to clear carpets and mats.
Where there is a tendency for rainwater as well as draughts to get under an external door, fit a two-part threshold draught excluder kit which fixes both to the sill and the bottom of the door for a perfect seal.
Brush type seals can be screwed behind letterbox openings to cure draughts here when newspapers are pushed through.
Hinged and pivoted windows are easy to
draughtproof using self-adhesive foam tape
to seal the surfaces that close together. Many draught excluders are suitable for doors and hinged windows.
The action of sliding sash windows tends to push off ordinary draught excluders, so use nylon pile self-adhesive tape, or ideally nylon stripbrush in a PVC or aluminium holder. Tack it around the frame with the stripbrush pressing against the sash.
The irregular gaps often found on metal casement windows can be sealed with silicone rubber sealant which is injected into the gaps after the window face has been protected with release tape which can be clear sticky tape. The sealant sets, but sticks only to the frame.