Most Home Inspectors walk around with some pretty cool tools in their tool belts or tool bags.  They have assorted flashlights, screwdrivers, cameras, mirrors, electrical testing equipment, moisture meters, and even marbles.  Some will loose their marbles every now and then---but most get the job done.

     Not only do we have to know what these tools will help us do, but we must also be mindful of what they cannot do for us.  For example the moisture meter is an indispensible item in our tool bag and it can be our "seeing-eye-dog" on the inspection. 

     The better moisture meters have the ability to read surface moisture as well as moisture at depth in materials.  These "sounding" or "depth-reading" type moisture meters are great for telling us if there is moisture under floor coverings around toilets and tubs; as well as behind tiles in tub and shower enclosures.  They can find moisture where we can't see it and confirm moisture where we suspect it. 

     They can sometimes tell us there is moisture when there actually isn't any.  These are called "false-positive" readings.  All tools have their abilities and limitations and the inspector needs to be experienced with both aspects so as to be able to best interpret his or her "visual" and "technological" findings.   Otherwise, recommendations to our buyer might not be complete and actually cost someone in the process a lot of aggravation.  For example the inspector claims there is moisture under the floor covering around the toilet---his moisture meter says so----so it must be so.  But, if there are boys in the house, it could be false positive readings from the salts present on the floor.  A simple cleaning of the area and re-testing will give better information.  Having someone rip out a toilet, or worse yet, rip up the floor and find nothing would be at best "embarrassing" and at worst might cost the inspector some money.  Usually there will be a combination of symptoms that support each other in the quest to come to a "meaningful" conclusion.

     It is my routine in finished-basements to test around the perimeter of the walls that are below grade.  I test for moisture every two to three feet to get a sense of any "current" problems related to the covered foundation.  Stains, previous repairs, or swelling of finish materials would obviously rate extra scrutiny.  Any time you install finish walls over foundations, the potential for hidden moisture concerns is high----especially in older homes that didn't have the drainage technologies that we do today.

     On a recent inspection, while testing around the perimeter, I came to an area about 18 inches long that tested as "positive" for moisture and if you looked at the area very closely one could make out a faint outline of area that was a slightly different color----but very subtle.  Can you see the area in this photo?

     Now, after seeing the area outlined in this next picture, can you see it?

     At this time, I had to bring out a very specialized tool to aid in the investigation.  It is an adaptor that attaches to the moisture meter and is able to "smell" the wet area.  In this case it turned out to be pet urine---the distinct smell of cat pee.  Cats will often "mark" their territory around the perimeter of basements and often fool the moisture meter.  Here is a picture

of this highly specialized tool----

every inspector has a similar one----

and hopefully they use it where necessary.

Of course there are those instances when no tools are really necessary.

Charles Buell

     PS, for those of you that are new to my blog (or for some other "unexplained" reason have never noticed)all  pictures and smiley-face inserts (emoticons) (when I use them) have messages that show up when you point at them with your cursor.