by Charlie »
Mon Jun 11, 2007 3:23 pm
Orlandowren-
a couple of points.
1. The damp test is open to scrutiny depending on how the test was carried out. If the areas tested were done so with a calcium carbide meter or hygrometer than the findings should be reasonably accurate but if (most likely) they were done using an electrical resistance meter than treat the results with caution as those meters are calibrated for timber and only give indicative readings. The presence of salts or foil backed plasterboard are examples of when these meters may give misleading results.
2. There are thousands of houses in the UK without dpcs that do not have rising damp problems. Rising damp (true rising damp- groundwater) is a lot less common than people think. The problem is usually condensation, water penetration, defective underground drainage (which can appear to be rising damp) or the likes of a defective downpipe. Older houses were not built with dpcs and were constructed so that the structure could absorb water and release it through evaporation- sometimes the incorrect specification of materials leads to damp problems- such as replacing a lime based mortar with a cementicious mortar which will not allow the building to breathe as it should.
Get a good building surveyor to assess the problem- it will probably save you money in the long term.