I was asked to carry out a survey of a 1970’s bungalow which is of cavity construction in Trowbridge Wiltshire. I was told that the property when surveyed for pre-purchase had a condensation problem but now after re-plastering it seems to be a rising damp or a cavity wall insulation problem?!?! And could I investigate further.
As a surveyor you always have an idea of problems and defects associated with certain types of houses in your local areas, this property was literally a 2 minute drive. I knew this property wouldn’t have a genuine case of rising damp from a failed damp proof course as such, which I explained to my client.
The problem was in the rear bedroom and right hand side bedroom all sharing the same external wall though, I will say this wall isn’t taking the weather either. This is what I could see on the internal walls.
So all we can see is what looks like the walls haven’t dried down from re-plastering really, but all the other walls in the house have dried down and it was re-plastered 4 weeks ago. So I would say something isn’t quite right!
Externally the ground was saturated and I was told a drainage system has recently been installed to combat this.
I got the hygrometer out and checked the relative humidity, air temperature and dew point, this allows me to check for condensation related problems internally….This is a quick check and only offers a snap shot in time, being May you wouldn’t think that you would have a condensation problem but this property has been completely re-plastered which has introduced gallons of water and also there has been no form of heating. At that present time there was no condensation related problem.
Any decent surveyor that is interested in trying to find the real cause of damp or rising dampness within a cavity wall construction will have a boroscope/endoscope. Any damp problem on a cavity wall will need the cavity inspected because this is where the problem normally is. I selected the area that looked visibly dampest internally and I drilled the cavity wall externally in this area with a 12mm bit and inspected the cavity, I could see small amounts of debris, but nothing serious. I could see the physical damp proof course just about level with the internal brick (no overhang).
I removed a stone externally as in the picture above to have a closer look, this shows the physical damp proof course.
Looking at this I didn’t see an issue with this so I asked my client if it was ok to look at the floor and wall junction internally. On opening up it is clear that physical damp proof course was not completely over the brick, it was about 15mm short! The internal render was also going down past the physical damp proof course and touching the floor which is drawing the damp up the wall-rising damp.
This is what I could see.
So did this bungalow In Trowbridge Wiltshire need damp proofing?
No it didn’t, a remedial damp proof course wouldn’t have fixed this problem. My client was advised it needed a new damp proof course and one company even said it needs tanking. These are both trading as damp proofing specialists, they are not qualified and are not members of the Property Care Association. They offer no diagnosis of the real reason for the dampness, and the reports are one page. They offer a guarantee, but it’s not a true Insurance backed guarantee by the GPI.
The moral of the story is, if you need damp proofing or need a damp proofing survey, it is always best to look for a qualified damp proofing surveyor who is a member of the Property Care Association.
If you need a survey contact Complete Preservation on 01225 769215