The builders of a large condo building had had problems for a while with a bathroom vent connection leaking into a bathroom ceiling, but it wasn't the bathroom vent.
They had opened up the drywall so they could watch and sprayed the vent exhaust point on the outside of the building.
When they did they were unable to duplicate any dripping.
Prior to my arrival there had been many days of heavy rain.
And it had dripped into the bathroom during the rain storm.
However, my thermal camera was able to detect a cooler area on the subsurface of the roof above, coming from an area to the right of the bathroom. It can be seen to the left as the purple area, and clearly it is higher than the bathroom exhaust tubing.
So what gives? The roof is not even a year old, It is covered with TPO, which is a thick, thermal plastic membrane, which wraps continuously over the parapets on the side of the roof. Under it is an insulating Iso-foam layer, and then a wood subsurface. The thermal image is viewing the wood subsurface.
So it was up to the roof!
The parapet can be clearly seen around the edge of the roof.
The seam in the TPO can be seen along the lower edge of the image. The membrane is "soldered" together, glued essentially, with long seams which were all intact.
We were there about 915am on a sunny day. Things had not gotten warm yet, with outdoor temps around 72F. There was no moisture anywhere on the roof. The surface was entirely dry.
But moisture UNDER a TPO membrane will get warmer quicker than the Iso around it. I took two temperature measurements for comparison. It it obvious that the yellow area is warmer than the surrounding roof membrane.
Walking over the unit with the bathroom ceiling leak I didn't even need to measure to get the geography right. Mighty Mo was able to see problem moisture under the surface.
Looking over the parapet the bathroom vent exhaust is just to the left.
So the leaking is coming from somewhere in the parapet. Once the location is established a fix can be planned. And the problem can be solved!
My recommendation: thermal cameras can be used for many things. Sometimes what appears to be the problem turns out to not be it! Hopefully the true source of any leak can be found. They called me before the rainy weekend and I suggested we wait until the first sunny day to make the diagnosis. Today just happened to be a good day to diagnose this issue. And I think we were successful.
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560