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Just checked my humidity meter on a slab I poured Tuesday...
I've been finishing concrete for about 8 years now and always kind of guessed on when to start troweling based on feel. Last week I borrowed a buddy's digital concrete moisture meter and checked a 20x30 patio I poured outside Tulsa. Turns out I was starting about 45 minutes too early on average, which explains why some of my earlier jobs had that slight dusting issue. Has anyone else tried timing trowel starts with one of those meters instead of just going by touch?
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danielmartinez3d ago
Wait, have you noticed if the meter readings changed much between different spots on the same slab? I borrowed my neighbor's moisture meter last fall for a small garage floor I did near Broken Arrow and it showed a 12% difference from one side to the other. That made me wonder if the ground prep or subgrade moisture was throwing off the cure time in certain areas. It really makes you think about how much guessing we do with that old thumb test when the numbers tell a whole different story.
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wrenstone3d ago
Did you check if the slab was poured on a vapor barrier? That 12% swing could be from water wicking up through the ground on the high side.
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