Older vs Newer Buildings
Older and newer buildings have been built very differently.
Older buildings have been designed and built to be water permeable. They get wet, they dry out. Being built from breathable materials, they naturally dry out.
Newer houses on the other hand are built watertight using modern materials (including many plastics) designed to keep moisture out.
As a result, they should be treated differently. They should be renovated with similar, traditional materials with as little destruction to the building fabric as possible. Newer, modern materials which are very different from traditional ones, should be avoided.
Mixing old and new technologies has a detrimental effect on old buildings, usually leading to their rapid decay. Here are some of the reasons why:
- Hardness: new, modern building materials are harder. A new modern brick for example is expected to be be stronger than a 400 year old aged hand-made brick. Thus when old and new materials are mixed together, the older and softer materials will give way and suffer, leading to the gradual loss of the original building fabric.
- Breathability: newer materials being less breathable, they do not allow for the evaporation of moisture. The accumulated moisture will again damage the weaker and older materials resulting in the decay of the historic building fabric.
Now, this does't mean that you shouldn't use any modern building material in an old building. Life is an evolution. Buildings are also constantly adapted to new uses to suit a purpose, and this often involves significant changes. However, without extensive knowledge of materials and/or building physics one can seriously damage old buildings - most of the time, unwillingly.
Who Do You Take Advice From?
If you own or are about to renovate an old building, please do your homework and take advice from professionals (builders, architects, surveyors etc..) who are knowledgeable about old buildings and building materials - not just your average builder.
When looking for a builder for your project, one of the first questions you should ask is this: "Are you working with lime?" and if the answer is no, then look for someone else. There are tradesmen specializing on old buildings and lime; you can find them online or through word of mouth. The Listed Property Owners Club (LPOC) also has an online suppliers directory where you can search for reputable tradesman for your area.
On the next pages we are going to cover some of the practical fundamentals on how to renovate old buildings especially from the viewpoint of structural dampness, or dealing with rising damp or rising damp related renovation matters. We are going to cover in detail the effect of ground salts, the types of plasters recommended for such work, the most common mistakes and more.
Hope you find this information useful.