Vacant house, for some time. Walk through and offer a week or so before our inspection. Lingering smell in the house then. Lingering smell as we walked in the door. Standing in the entry everyone turned to me to ask, "What's that smell?" Well, the smell was moisture, and it was established!
"Let's look around the outside first." Usually I am at a house earlier than the buyers and have walked around the house a couple of times. In this instance, they were very early and I hadn't had my usual shot at that! I love it when the buyers are early, by the way.
What did we see? Tall trees and fallen limbs.
TREE LIMBS DON'T LOOK HEAVY. THEY ARE. WHEN THEY FALL ON HOUSES THEY CAN DO DAMAGE.
These limbs weren't huge. One larger one was beside the corner of the house, and there was evident damage above to the gutter and lower end of the roof. There were shingles damaged at the peak of the roof, clearly visible, but no limbs residing. One must have hit and fallen off or was blown off by wind.
This is how the thermal camera saw the peak of the cathedral ceiling at the top of the roof.
NO STAINS WERE VISIBLE ON THE DRYWALL. So this problem would have been invisible without the camera.
Interestingly, the left image is the front of the house, in the sun. The right image is the rear, more oblique to the sun, but also shaded. White, yellow and orange indicate warmer colors in this palette.
You can clearly see how warm the ceiling and wall are in the left image, at least by comparison to the right image!
And the cooler colors, as demonstrated by the dark purple and blues, are more pronounced in the left as they show a starker contrast. This is very instructive. Shade on the outside of a house can throw you off if you don't pay attention!
Those cooler colors clearly indicate moisture. There is no other reason for cooler colors on a day in the 90s. Why would that moisture smell? Think carefully!
And what of the lower end of the roof near the damaged gutter?
This is what the corner of the bedroom looks like behind that damaged gutter. Flat ceiling, 90 degree wall, and again, moisture evident. This is also a shaded area, on the other end of the house. Notice how the first stud in the wall has diverted the moisture lower down, where it has migrated a bit across the wall via insulation.
So, remember the formula: broken limbs + damaged shingles = moisture. But all the time? Maybe not. IT WORKS IN THIS CASE THOUGH!
Why the smell? While not visible on the interior of the drywall yet, there is probable fungal growth in there as this problem has had time to develop and given "conducive conditions" (i.e. moisture) fungi and molds can take root rapidly!
This is an easy thing to refer to a roofer for repairs and a mold remediation company for assessment and eradication. My job is done!
My recommendation: thermal imaging is useful, instructive and the images are definitive. Extremely sensitive to temperature differences, these cameras can demonstrate exactly where such differences are. Moisture presence, falling insulation, electrical anomalies, leaking duct work, animals inside the wall - anything that can produce temperature changes can be detected by the camera. It is fabulous technology.
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560