If I am called out to look at damp patches on walls and ceilings I grab my little two pin moisture meter and stick it in a few different places.
It works well enough but it can only tell you if there is enough moisture in the wall to conduct a small electrical current.
It can’t tell the difference between rising damp, penetrating damp and condensation.
That is largely down to experience but increasingly these days I am dealing with rented properties where people are inclined to blame the landlord rather than their own life style.
Understandably they are trying to conserve heat by keeping the windows closed but they may also be drying washing on the radiator.
You can tell them that the likelihood is that the problem is condensation but in my experience they are not necessarily going to believe you and you end up as piggy in the middle.
What you need is scientific evidence and this Flir thermal imaging moisture meter MR 176 can give it to you. It measures the relative humidity and temperature in the room and gives you a dew point.
You can then home in on the area highlighted by the thermal image cold spot and either go for a non-intrusive moisture reading or you can stick the built in probe in and get the same kind of reading you would get with that £15 moisture meter from Maplin.
The difference is that you have data and snap shots of the thermal image that can link the highest levels of moisture with the coldest spots as you would experience with thermal bridging. You can download it into a report and, more importantly, charge for it.
This is a different approach to the days when you called in a damp proofing company whose surveryor (salesman) would give you a ‘free survey’ and recommend the same remedy for all damp regardless of the cause.
In my time I have seen countless houses stripped of their plaster up to a height of 1 metre and given a stiff coat of waterproof render and an injection of silicone, neither of which were needed and if anything often made matters worse.
In fact some years ago I did a special report on the damp proofing racket for BBC’s Watchdog and made many enemies in the world of damp-proofing.
Probably the worst example of mis-selling was a company that hacked off all the plaster even on the internal walls and injected fluid and water-proofed render in a flat.
The flat was on the third floor of a modern block. There was no way it was rising damp. In fact it turned out to be a plumbing leak.
Back then thermal imaging was only used by the military and rescue services. The Flir MR176 isn’t cheap but it is now well within reach of the smaller builder or property maintenance company.
Let’s face it nobody wants the disruption of having their plaster hacked off if it isn’t essential and if it does turn out to be condensation there are now plenty of heat recovery ventilation units that can be installed in houses and flats.
A more scientific approach to damp problems is long over-due and this device makes it possible.
For more information visit www.flir.com
