High Rapid RH readings??

[CC Solutions]

Bottom line, you have a wet slab.

RH levels do actually fall rather quickly once the slab starts drying. By rather quickly I mean a 1 - 2 points a week if conditions are right.

As long as you have done the testing according to the instructions in your test kit, you can trust the readings. You should be 2.4" into the slab, brushed and vacuumed holes, drilled straight and true, you don't wet drill right?

If it makes you feel any better, I did a job last fall where they waited 16 months for suspended floors to dry and they were still at 98%. The 4" slab on grade areas were down to the mid 80's to low 90's.