Just got back from a job in a new subdivision and noticed something weird with the subfloors

I was doing a big master bedroom in a new build out near the edge of town. The concrete slab had this funky texture like they poured it too dry. My glue down was not sticking right at all and I had to stop and call the builder. He said they switched to a cheaper concrete mix to save money. I guess the humidity was way off too because my moisture reading hit like 8.5%. Has anyone else run into shoddy subfloor prep in new construction? I wasted half a day on that spot and the builder didn't even warn me.

3 comments

3 Comments

the_hayden17d ago

That dry mix probably threw your glue's open time off too.

jamesfox17d ago

@the_hayden you're probably right about the dry mix causing issues, but I think the glue type matters too. Some PVA formulations handle drier conditions better than others in my experience. Just something to consider if you run into the same problem again.

derek99417d ago

Hold up, James, I gotta push back on that PVA thing a little bit. PVA glue is water based, so if the concrete is dry and thirsty it's actually going to suck the water right out of the glue even faster, not help with open time. The issue isn't the glue brand, it's that the slab wasn't cured or sealed properly before anyone started troweling. A dry mix that porous is basically a sponge. You could use the most expensive glue on the market and it'd still let go if the slab is drinking up all the moisture out of the bond.