Thermal Imaging Building Envelopes with Moisture Scanning

 Do you plan to do moisture scanning on building envelopes with your thermal imaging camera?

Personally I’ve performed 100’s of thermal imaging inspections looking for signs of moisture in homes. Let me set something straight with you right now. If you expect to walk into a home and see signs of ‘moisture’ (not leaks) behind a wall using only a thermal camera, then you better revise your plan.

Moisture behind a wall and within the building envelope can be seen using infrared, but conditions have to be optimal otherwise you’ll miss it due to the fact it’s usually wide spread… and with a low cost thermal imaging camera with ‘average’ thermal sensitivity, you’ll be sure to miss it.

So how do you detect moisture within a building envelope? Depends what you are looking for… is it simply moisture behind the dry wall? Latent moisture in a flat roof? Me, well I keep it simple. If you aren’t sure what a moisture meter is, then go to eBay and find out. You can get a ‘non-invasive’ meter that doesn’t put holes in the wall, or you can get an invasive meter that does put holes through the wall. This will actually be the primary device to use when doing a home moisture scan (from the internal side).

In Canada, you may have heard about the leaky home problem? Well a quick way to find out if the cladding (usually monolithic polystyrene type) has let moisture penetrate through onto the timber frame, is to insert moisture testing probes (Invasive moisture meter) through the drywall and into the center of the timber frame. This will give you an initial idea if severe moisture problems are taking hold behind the wall. As you know, moisture in timber will usually cause it to rot… gradual moisture damage. 

The most accurate and conclusive way to determine if moisture ingress has caused damage within the building envelope, is by taking a core sample of the timber, but penetrating through the cladding (outside of the building), not through the inside walls of the home. The reason for this, is that if there is moisture ingress taking place, then the first area of timber to suffer is going to be closest to the cladding.

This type of moisture testing mentioned above is just one way to test.  Here are some infrared photos of moisture testing using thermal imaging here