Preparation

If you have bought or are thinking of buying an older house, take time to find out about the building. Read the information provided by the Society for the Preservation of Ancient Buildings and, if necessary, engage a surveyor who is experienced with older buildings.

Very often the biggest task facing the new owner of an old house is undoing past work. Many old buildings have undergone several decades' worth of inappropriate repairs and 'renovation' which have often made matters worse. It not only looks wrong, but it jeopardises the integrity of the building.

First Steps

The first step should be to make sure the shell of the building is sound. Check that the roof and the walls keep the elements out and that structural timberwork is safe and free from decay. Sometimes decay and damage in timber elements may be covered by modern render and plaster, so be prepared to investigate beneath the building's 'skin' if necessary.

Structural issues should be tackled as a matter of priority. A leaking roof will eventually affect everything underneath it, while rotten and decayed structural timbers are potentially dangerous.

Damp

Damp is the biggest single cause of concern for would-be buyers of old houses. Whole industries have grown up to provide impervious renders, chemical damp-proofing and magical compounds to prevent damp. Most of them are a waste of money, and the most effective treatments are often the simplest.

The 'rising damp' beloved of surveyors is actually surprisingly rare, although it is more common in houses which have been 'renovated' with cement renders, concrete floors and modern plaster.

Far more common is penetrative damp from either rainwater or poor drainage. Both of these are usually straightforward to solve. In short, on a stone or other solid-walled property without an existing damp-proof course, the best way to counter damp is to remove the cause as far as is possible (by attending to ground levels, guttering and drainage) and to use breathable plasters, pointing and renders.

Materials

it's rare to find a house that has not been repaired at some stage with cement-based materials. These are fine for modern buildings, where the whole structure is designed to be impervious to moisture, but an old building is designed to 'breathe. Thus on an older building such materials can cause or accelerate serious decay,trapping moisture in the fabric of the building and directing it inside rather than outside.

If brick or stonework is repointed with cement-based mortar the decay of the building material is accelerated, as the mortar is harder and less permeable than the stuff it is binding.

In both cases the most sympathetic and sound approach is to replace cement-based materials with breathable lime-based renders, plasters and mortars.

These also have a greater flexibility, enabling render, plaster and pointing to accommodate the structural movement that is inevitable in an older building. All too often, modern materials simply crack, creating pockets which can trap moisture.

Timber elements of the building - doors, windows, soffits and fascias - are as much a part of the character as bricks and stone, and should be retained wherever possible. It is usually cheaper, aesthetically more pleasing and better for the environment to repair timber elements than to replace them with modern uPVC equivalents.

Advice on these and many other issues affecting older houses can be found in the forums and technical papers at the Period Property website and in the Q&As at SPAB.