Loadingā¦
25
Hot take: saw cutting control joints too early on a 90 degree day in Phoenix ruined a whole slab for me
I cut joints 4 hours after the pour last Tuesday and got raveling so bad along the edges it looked like a beaver chewed the lines. Now I wait 6 to 12 hours no matter what the GC says, because fixing that mess cost me a whole Saturday and a $75 tube of epoxy. Anybody got a temp and humidity rule they actually trust for timing cuts?
1 comments
Log in to join the discussion
Log In1 Comment
the_spencer3d ago
The "wait 6 to 12 hours no matter what" part is what I'd push back on. Concrete doesn't care about the clock, it cares about how set the mix is. On a 90 degree day in Phoenix with a hot mix, that slab might already be too hard at 4 hours, but on a cool overcast morning the same 6 hour wait can still be too soon and you get the same raveling. What I actually trust is pressing a thumb or dragging a nail across the surface near where the cut goes. If the edge crumbles or pulls, it's still too green. If the blade throws gritty dust and the line stays clean with no tearing, you're good. So the time window moves with mix design, wind, and sun, not just temp and humidity.
8