My uncle insisted I needed a $200 moisture meter before tiling my bathroom floor

He's been a contractor for 30 years, so I listened and bought one. I was about to just slap the mortar down, but the meter showed the concrete slab was way too damp, like 85% relative humidity. I would have had a total failure in a few months. I ended up having to seal the floor with a specific primer and wait a whole extra week for it to dry properly. It was annoying at the time, but now the tile is perfect, no cracks or hollow spots. Honestly, I would have skipped it to save cash and time. Has anyone else had a tool they almost didn't buy save their project?

4 comments

4 Comments

lee58223d ago

Okay but 85% humidity on a slab, is that really a guaranteed failure? I've seen plenty of tile go down on damp concrete and it holds up fine for years. Sometimes these tools just make you overthink things and buy more products. Your uncle's advice is solid, but I wonder if the primer was the real fix, not the meter telling you to wait.

blairm7723d ago

Actually, that high humidity can corrode the metal lath under the tile.

nora_webb5123d ago

Sometimes you just get lucky with a damp slab and nothing goes wrong.

schmidt.iris19d ago

My uncle had a bathroom floor that sat on a damp slab for six years before anyone even noticed a problem. The grout crumbled first, then we saw rust stains seeping up through the tile. So yeah, you CAN get lucky with the right conditions and a well-drained slab that airs out over time. I know a guy who did tile in a basement that was at 90% humidity and it held up for a decade until they sold the house. It really is a gamble every single time, and sometimes you win.