Moisture in decks

[mercedes]

How Tos on the internet have one drilling in holes and applying dry rot, epoxy.
Had step to mast redone this summer at great expense. Originally their moisture mete showed some moisture about a foot away from mast step which was repaired. I bought a moisture meter but not a good one and does not show the moisture. Called a fiberglass guy 3 times and he does not call back. What to do?

[psk125]

Moisture meters are notoriously finicky. Try from both above and below. A boat we were looking to buy had moisture meter readings from the outside of the hull below the waterline that screamed "run away!!!", and readings from inside showed no moisture whatsoever. We surmised that the moisture was in the ablative antifouling paint, because there was no delamination. We've had the boat more than 20 years now.