Heat insulation will be largely wasted if your house is draughty. It is no good warming the air in a house if the wind just blows in and replaces it with cold air. Curing draughts is cheap, quick, and easy. It is not only old houses that are draughty. Modern ones, too, have cracks and gaps through which air can pass. Even if you cannot feel a draught, heat may be pouring out wastefully and being replaced by cold air-a process that loses you money as well as comfort. Even a well-fitting door lets in an amazing amount of cold air unless it is properly sealed around the edges.
Wooden window-frames, especially in old houses, are no better. In particularly draughty houses, more heat may be lost in this way than any other. Many types of door seal are sold. The cheap kinds work just as well as the expensive ones, but do not look so good. One of the cheapest is a simple felt strip that is hung from the bottom of the door by a strip of adhesive backed plastic. This type is particularly good for irregular floors, because it does not get caught as the door moves. More expensive draught excluders are often attached to the threshold itself and not to the door.
They are generally made of metal, and are screwed or pinned to the threshold so that they line up with the bottom of the door. The great advantage of this type of excluder is that it keeps rainwater from seeping under outside doors. The sides and top of a door may be nearly as leaky as the bottom, but need a different type of sealing. One highly effective type that can be used around doors and windows consists of thin metal strips that are nailed to the frame where the door or window touches it.
After nailing down, they are bent outwards so that they press hard against the door or window to provide a tight seal. Some types of strip come with instructions and a special bending tool. They are quite easy to install. Others must be put in professionally. A cheaper alternative for doors and windows is self-adhesive plastic strip. This is bought in rolls and simply stuck to the door or window frame. Be sure to clean dirt and grease from the place where it is to be stuck.
A chimney takes a lot of heat from a room if there is no fire in the fireplace. Closing off the chimney opening is an advantage, but it should never be blocked completely, or it may cause condensation and damp patches on the walls. The fireplace can be closed off with hardboard or some similar material, leaving a tiny gap at the bottom to ventilate the room without too much heat loss. Or, better still, it can be bricked in for a neater appearance, so long as ventilation bricks are provided. In draught-proofing, ventilators such as air-bricks should never be blocked up. Even the best-insulated buildings need a small flow of air, without it, condensation or dry rot may result.