While invasive testing methods may sometimes be necessary to determine the source and extent of damp problems in buildings, there is a variety of frontline tools to assist in the initial diagnosis. Electronic moisture meters, surface thermometers, hygrometers and data loggers all have their part to play. For experts like Brick Tie Preservation in Yorkshire (UK), these are indeed standard tools-of-thetrade. The company also has its own salts analysis and gravimetric testing lab for masonry samples. With all these available options available, it still chose to add thermal imaging to its arsenal.
Thermal imaging has the ability to see the ‘big picture’ in an instant and to factor in hidden features and defects that have a bearing on the damp problem; these can easily be seen on a thermal image through differences in heat transfer and heat retention. Brick Tie Preservation’s MD, Bryan Hindle, compares his thermal imaging camera to a time-machine that can help him see the building’s history.
“ Al though building thermography isn’t rocket science, it does require sound understanding of how it works and what influences equipment and results,” Hindle explained. “I think a Level 1 thermography qualification is perfect for anyone starting out in thermography and I refused to contemplate using an IR camera in my work without it.”
Next step was to decide on the most suitable thermal imaging camera and as a result of his training, Bryan realised that an entry-level model would be false economy for his business. Whilst they are a good choice for basic troubleshooting, they do not have the performance and functionality needed to see complex problems evidenced by subtle temperature differences.
With expert guidance from Stuart Holland of TCL, himself a Level III thermographer, Hindle chose the FLIR T420bx with an additional wide angle lens as much of the company’s work is performed indoors.
According to Hindle, the FLIR T420bx provided the ideal combination of functionality, sensitivity and resolution. “Having tried cheaper ‘pistol grip’ type units I find the ergonomics of the swivel lens and hand grip much better in use.”
He added: “Good sensitivity is a particularly important criterion as I can’t count on high temperature differentials and I need to deal with conditions as I find them. Preparation counts for little if, for example, the doors and windows of a building are open when I arrive making the measurement conditions far less than ideal.”