Rising Damp Wrongly Diagnosed
This is a problem I come across often on timber and damp surveys, I was contacted by a potential home buyer concerned about a damp survey she had carried out by her mortgage lenders who recommended a timber and damp specialist to carry out a damp proofing report.
She explained the problems to me over the phone saying the house sale might drop through because of RISING DAMP throughout the ground floor of the property and wants a second opinion.
I asked a few questions about the property like age of property, is the building a semi, terraced, detached, bungalow and what’s the construction of the ground floors like timber suspended floor or solid flooring, her reply was semi-detached 1930s (approx) and timber suspended floor throughout so now I’m thinking “1930s property rising damp on timber suspended floors something is not quite right relating to this problem of rising damp so I arranged a damp proofing survey.
Upon my arrival at the property I noticed a dense rendering on all external walls and thought I have a very good idea of what the problem is, firstly we walked around the outside so we can see if there are any potential problems relating to the internal walls and floors, properties of this age would have a slate damp proof course built into the mortar joint on construction but in this case the rendering was causing a breach over the DPC as seen on images.
This causes low level damp on the internal plastered surfaces, the majority of subfloor air bricks had been covered by the rendering which was giving the sub-floor inadequate ventilation leading to possible timber decay in this instance the floor timbers including joist bearing ends was in satisfactory condition.