The debate on when to start the power trowel on a hot pour

I keep seeing guys start the power trowel way too early on a hot day pour. They hit it as soon as it can take the weight, maybe 2 hours after placement. In my experience, that just seals in bleed water and leads to a weak, dusty surface later. I wait until I can press my thumb into it and leave only a slight mark, which is often closer to 3.5 hours in 85-degree sun. The other side says waiting that long means you're fighting the set and working too hard. Who's right here? What's your rule of thumb for timing on a fast-setting mix?

2 comments

2 Comments

mia_fox981mo ago

My crew in Phoenix starts around the 2.5 hour mark on those brutal days. Honestly I've seen both ways work fine, it's not like the slab explodes if you're 30 minutes off.

juliam401mo ago

Phoenix at 2.5 hours? That's just asking for trouble.