t
G.R.Coleman. 2000
To compound this problem houses were often externally
decorated with non-breathable paint or rendered
with hard dense cement rich finishes. These
applications reduce evaporation significantly
from the outside surface which then cause damp
to rise further up within the wall with the
resultant internal damp staining.
When renders crack they allow water to penetrate through, either by capillary action into fine cracks, or directly into larger cracks and debonded areas. The water is then trapped behind the render and can penetrate to the inside face of the wall structure.
Consequently, by the 21st century a great many old traditionally built houses now have damp problems often caused over the last 100 years, by changes in heating, ventilation and wall finishes.
Due to a lack of knowledge and understanding of older buildings, traditional materials and the way they work together, these damp problems have not been addressed correctly.
People buying houses do, for the most part, expect them to be weather proof with a dry interior.
Conservation of houses means that they have to be owned and lived in to be cared for. They have to be fit for this purpose.
How to conserve these properties and make them fit for purpose is driven by two opposed camps.
Some conservationists want the very least intervention into the property, so that the historic fabric and features of the property can be preserved for future generations, which is laudable. However, many firmly believe that when a property is damp the application of lime plasters and lime wash can reverse the problem, by allowing the walls to ”breathe”, even when the way the whole building functions (i.e. modern heating and ventilation) has changed since it’s original construction.
At the other end of the scale some Preservation companies consider any visual damp, or damp recorded on a meter around ground floor walls, to be indicative of a rising damp problem. This, they will recommend can be cured by insertion of a chemical damp proof course, followed by hard moisture resistant sand cement render. This is often detrimental to the older traditionally built buildings. Given that there are probably 3000 trading preservation “specialist companies” (and many more builders who will have a go at it) and that there are only a few hundred with any qualifications (and far less who genuinely understand older buildings) this leads to unnecessary and often damaging work to historic buildings.
Then there is the middle ground: Experienced building professionals in both the conservation and preservation industries who understand the importance of keeping older properties in good condition so they can be preserved and who can also identify historically important elements and features, which must be conserved. However they also
realise the practical issues of carrying out effective long term repairs and treatments, so that the occupants can enjoy living/working in these buildings and therefore continue to look after them.
There are a number of basic environmental health requirements for occupying a property, or bringing up children and housing the elderly, the most basic is that it must be dry and warm.
Some people not in these groups may decide to tolerate some damp in a house because they consider the well being of the house to be more important than their own creature comforts. However these people are few and far between. There is a far larger group of people who would impose damp conditions on people living in old properties due to a lack of understanding of the problems.
the house at the best price.
The Royal Institute of Chartered Surveyors, Trading Standards, and even The Estate Agents professional bodies, all state that surveys should be carried out by a qualified CSRT surveyor, and any work should be carried out by a BWPDA member company. This is often in the terms of the mortgage company instruction. However, many Estate Agents will try and use a cheaper unqualified company for a free survey. It is these companies who, through a lack of training and understanding, will usually in an effort to provide the cheapest quickest fix, recommend an injected chemical damp proof course and associated cementitious re-plastering.
Given that the survey is free there is some pressure to find some work. It costs on average £70 to attend a property write a report and send it. These costs have to be recovered somewhere.
In the ideal world, surveys would be commissioned by Building Surveyors or Architects who would undoubtedly use a surveyor or company that they knew to have the relevant experience , knowledge and qualifications. If Solicitors had a better understanding of guarantees they would insist that work was carried out by qualified companies, guarantees issued were meaningful, enforceable, and underwritten by insurance (and not by chemical companies) for the protection of their clients. This would ensure that companies do not use chemicals unnecessarily, just to comply with the terms of the guarantee.
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