Draught Proofing Chimneys, Flues and Service Penetrations

Warm air rises, so an unused chimney provides a simple mechanism for drawing warm air out of your home. The most effective way to prevent this is to board up the fireplace altogether. This was common practice in the eighteenth century in the summer months, when the fire was not being used, in order to reduce unwanted draughts and prevent soot entering the room. Chimney boards were designed to fit the fireplace and were often painted to mimic a view of the open fireplace, typically with a vase of flowers standing in the hearth. This method can still be used today for unused fireplaces (and artists can still be found who specialise in painting them). To be effective the board must sit tightly within the fireplace.

If you do not want to board your fireplace, either close the metal damper that seals the flue or install a chimney balloon. Chimney balloons are a proprietary product designed to be inflated within the chimney. When fully inflated they still let a small amount of air pass which prevents damp building up in the chimney. If necessary, they can be removed in summer to increase natural ventilation for cooling.

The cables and pipes that penetrate the walls of your home can cause major draughts if the junctions are not properly sealed. This is often the case in traditional homes where pipes and cables have been fitted in the twentieth century without due care. A mastic sealant is usually all that is needed to seal these gaps, though this may not be an easy job if the services are hidden or difficult to access.