• Gabe Semenza

So, what's with that staining?

A great number of homes that weren't built just yesterday typically include predictable issues. A bit of wood rot outside. At least minor roof hiccups. Electrical-system items that were acceptable when the home was built but which fall short of the standards of today.


One of those common issues is staining. The older a home is, the more likely I'll find staining - unless the home's interior walls and ceilings have been re-textured or painted. Even then, stains are common on attic ceilings, basements and crawlspaces.


So when is a stain a problem rather than just an indication that something, maybe long ago, occurred and left its mark?


First off, I try to determine whether the stain reflects active moisture. Using my hand, a sensitive moisture meter and also an infrared camera, I can learn very quickly if the stain contains moisture (even the almost-undetectable type that feels dry to the touch) or is dry and likely old.


The first tool I use is the Tramex Moisture Encounter Plus, a highly sensitive meter that can detect moisture levels in wood, timber, drywall, roofing, plaster and brick.


The following photo shows a meter reading of a stain in which the moisture level would be considered acceptable. Typically any area that contains moisture of more than 20 percent needs to be evaluated further and corrected if necessary. The tool alerts me to active moisture via the needle, which points to the a chart showing how much moisture the tool detects. It also audibly denotes active moisture (at 20 percent or above) with a loud beep.


One tool I use to measure moisture:

The Tramex Moisture Encounter Plus

The next tool I use to better attain a visual picture of the problem is the Flir infrared camera. I can look at staining and, via the live picture the tool displays, better determine if the staining is wet or dry.


Following are two photos, the first of which shows a ceiling stain. The next photo shows the view displayed via the thermal camera. It showed active moisture was present.

Upon finding the stain, I needed to determine if it was active or old.

Active moisture is indicated via the blue and green, or cooler, colors.

Even after using an infrared camera and determining the staining appeared active, I followed up with the handheld moisture meter (which confirmed the thermal findings) and reached the attic area located above the staining.


It turned out, active moisture was leaking from an attic-based air conditioner. The AC's primary drain line was clogged and spilling onto the attic floor, seeping into the living space. The cool blue and green colors you see in that photo above indicated moisture.


Here's the photo of what I found occurring at the AC drain line in the attic:


Luckily, this sort of problem was easily fixed and the moisture was stopped before it did major damage or caused mold. Had I not found the stain, used modern tools to gauge its relevance and followed up to find its cause, this relatively simple fix could have gone unchecked and caused great damage over time.


Oftentimes, stains do not contain active moisture, at least according to my tools. They can be simply a cosmetic blemish that hints of the home's history.


Unless you check, you might not know.


If your home has dark staining, it's prudent to have it tested for mold. This is a more involved process and beyond the scope of a typical home inspection. Samples need to be collected and sent to a laboratory for testing. My reports recommend further investigation of this sort whenever such staining is present.


If you having staining and want to know if it's active or not, I'm happy to help. If you hire me to do a full inspection, no worries. I perform moisture testing of stains and infrared scans of the home at no extra charge.


For your peace of mind, I am also certified in infrared and moisture intrusion.



Thanks for reading -


Gabe Semenza, InterNACHI certified home inspector and radon tester

406-240-7940

gabe@inspectmissoulamt.com