How to Detect and Test Moisture Behind Wall

Do You Suspect Moisture Behind Your Wall?

Do you wonder how the moisture is getting into you walls in the first place?

There are multiple reasons why moisture and leaks will find there way into your house walls, but for the purpose of this webpage we will just discuss water entry through cracks in the exterior cladding.

During a home inspection using thermal imaging, one of our thermographers detected signs of moisture and a leaks on the interior side of a north facing wall next to a window. You can see in the righthand photo below there is also a crack in the cladding in the exact same area.  (Keep reading underneath the photo)

crack in cladding

After detecting the moisture behind the wall on the inside, the thermographer then went outside with the thermal imaging camera to see if the water was also running down between the paint and plaster finish. You can see in the lefthand infrared image above the dark red colour indicating a ‘thermal anomaly’.

This dark read area is moisture behind the paintwork that has heated up in the sun at a different rate to the paint around it, as seen through the infrared camera.

How to you test the moisture content behind the wall?

Well you need to know the leak is there first. In this photo above, the leak may have gone undetected if it wasn’t for the infrared camera, because you couldn’t even see it with the human eye. In addition, the leak may have originated from above the window! 

Calling your nearest thermographer to do an infrared scan on your house could be the smartest starting point for your leak detection work… it’s non destructive, and could save you taking off plasterboard in places you don’t need to! They may uncover other leaks in the area also… and the extent the leak has reached in the wall.

Most thermographers who do leak inspections should have a non-invasive moisture meter to test the levels of wall moisture.