Traditional building techniques differ greatly from those practiced today in new builds.  Perhaps the most startling aspect of buying an older property is there is usually no damp proof course- a fact that often perplexes many buyers not used to living in an old house!

Because they don't have a damp proof course or cavity, traditional buildings, usually made of earth, brick or stone, will draw moisture up the walls. In order for this to evaporate to the outside, the structure needs to breathe and this is where lime mortar comes in.

Lime mortar has a greater porosity than cement and so lets the surface breathe.  It also allows a certain amount of movement within the structure, unlike its modern day counterpart, which will crack, let water into the wall and result in deterioration of the cob that has been rendered.  Lime mortar is in fact self healing and reduces cracking problems.

Cement masonry on the other hand has a tendency to separate from the wall, retain moisture and so increase dampness inside. The damp problem is also compounded by the use of modern day acrylic and vinyl paints which trap water in the wall.

The worst case scenario of a cob wall covered with cement will result in it falling out once water gets in!  But don't despair. Cob walls can be repaired and brought back to life and that's where we come in. Visit our 'Building with Cob' page and find out more.

             Damaged cob underneath the cement render

 Same wall rendered in lime to allow cob to breathe underneath