Moisture meter question

[Phil Thien]

Last week's Bob Vila show (I know, I know...) had a specialist that "kiln" dries new construction. Essentially, after a house is framed and sheathed, they close any openings and circulate hot, dry air using a truck-mounted furnace and air handler. Idea is to dry things out to the point of preventing mold.

Anyhow, the specialist drove two screws through the face of a 2-by and touched the pins of his high-end meter to the pins. He said this gave a better indication of the internal moisture content. The reading was several percentage points higher than the reading he got touching the meter's pins to the 2-by's surface.

I thought, "clever," but then it occured to me that the makers of the meter may not anticipate such fantastic contact w/ the lumber, and this may throw the readings way off.

Anyone ever seen this done before?

[Mike K Wenzloff]

The problem with just touching the pins to the surface on a pin-type meter is it will give a false reading.

Used properly, pin and pinless are close to commercial deeply driven meters.

The guy was pushing his service. Probably didn't need to go that far to make the point.

Take care, Mike

[Jason Hallowell]

That is just an easy way to get more accurate readings using cheaper pin type moisture meters, or an alternative to drilling small holes and using the probe tip atatchment on intrusive type meters. In that particular case the screw holes did not cause any damage that would be visible, but in many situations, the high accuracy non-intrusive meters are the way to go. When I worked doing water damage restoration and mold remediation, the expensive units were a must, but I don't see much of a need for them otherwise.

[Jason Roehl]

I just saw a resto company do this on a gym floor at a local HS that had some water damage. They drove nails in pairs in various locations for successive checks on their drying process. Where the cupping was the worst, the moisture levels started at ~35%, down to 10% on the undamaged floor. They were doing this in conjuction with pin-type meters (and some surface-scan), not just for more accurate readings, but to find out how much moisture was beneath the floor and how far it had spread underneath.