c/concrete-finishers

I finally figured out why my control joints kept cracking early

Last month I poured a 400 square foot patio slab outside Boise and the control joints started spiderwebbing within two days. I was using the old-school method of cutting them at 8 hours with a wet saw, same as I always have. Turns out the issue was my timing, the temps dropped from 85 to 50 overnight and the slab was still too green when I cut. I switched to waiting 14 hours and using a groover instead, plus I added more saw cuts at half the depth I normally do. The last slab I poured last Tuesday has zero cracks so far, which is a first for me with this weather. Has anyone else had trouble with early joint cutting in cooler fall nights, or do you adjust your timing based on the forecast too?

2 comments

finley_smith•1d ago

The 104 degree pour in Phoenix that made me swear off afternoon finishing

We poured a 40 yard slab for a loading dock at 2pm because the GC insisted, the sun baked the surface crust before we even got the bull float on it, and I spent 6 hours fighting patches that kept sticking to my mag; has anyone else told a GC to move a pour time and actually won that argument?

2 comments

the_nancy•2d ago

The bubble float in Tampa that ruined my driveway finish

I finished a 1,200 square foot driveway last week in Tampa and used a brand new magnesium float from a big box store. By the third pass the leading edge had a bubble in the casting, so it left lines I had to burn out with a steel trowel. Took me an extra 2 hours on a day the sun was already cooking the surface fast. Has anyone else had luck buffing out small bubbles before the final pass, or is it always a rip out and replace?

2 comments

adam186•4d ago

Skeptical about power trowel blades, now I only buy the expensive ones

I used to grab the cheap blades from the big box store for years, thought they were all the same. Last month I bit the bullet on a set of premium triple-tempered blades for my 36 inch trowel, cost me about $90 more. The difference in the finish was night and day, way less washboarding on a 5,000 square foot garage pour in Tacoma. The cheap ones would start chattering after an hour, these held up through the whole day without any issues. I'm curious if anyone else has noticed a big jump in quality with certain blade brands, or if I just got lucky with a good batch?

2 comments

angelamurphy•7d ago

Pro tip: switched from hand troweling to using a power trowel for my garage floors in Austin

Used to spend 3 hours on my knees finishing a 2-car slab with hand floats, then I bought a used 36-inch power trowel for $400 last spring and cut the finishing time in half, has anyone else found a good deal on a used one?

c/concrete-finishers

I finally figured out why my control joints kept cracking early

The 104 degree pour in Phoenix that made me swear off afternoon finishing

The bubble float in Tampa that ruined my driveway finish

Skeptical about power trowel blades, now I only buy the expensive ones

Pro tip: switched from hand troweling to using a power trowel for my garage floors in Austin

Hit 5000 square feet in a single pour last week and my crew still hates me

I finally tried power troweling over hand finishing for a big slab

Tried stamped concrete with a $60 mat vs a $400 professional stamp and the difference was night and day

PSA: I switched from a bull float to a magnesium hand float for small garage slabs

Old timer told me to wet the subgrade before pouring and I thought he was wasting time

Shoutout to the guy who told me to wet cure my driveway for 7 days straight

Just realized spending $60 on a cheap mag float was a total waste

Old timer at the job site taught me a trick I still use

Power trowel vs hand finishing for driveways - which holds up better over time?

My boss's truck backed over the fresh walkway we just poured

Overheard a guy at the supply yard say he ruined 4 yards of mix by not checking his form stakes first

Hit 5000 square feet in a single pour last Tuesday and my back still hurts

Shoutout to the old foreman who told me to quit overworking my concrete

That cheap foam backer rod trick saved me on a driveway pour in Austin

Hit 500 square feet of broom finish in under 4 hours yesterday

Switched from a hand float to a power trowel on my last flatwork pour in Tulsa

Trowel machine threw a blade at my shin yesterday

Hit 1500 square feet of flatwork in one day last summer, floored me

Broke down and tried the sponge finish on a driveway in Houston

Old timer on a bridge pour told me your hand trowel matters more than your $200 mag