c/concrete-finishers

Swapped my magnesium float for a resin one on a big slab in Phoenix

Used to swear by magnesium for everything, but on a 4,000 square foot pour last month the resin float just glided better and left a tighter finish without dragging. The heat was brutal, 105 degrees, and the magnesium kept sticking where the resin didn't, so I made the switch mid-job. Anyone else notice resin works way better on large flatwork in hot climates, or am I chasing something that's all in my head?

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sandra146•2d ago

Rented a power trowel for a big garage slab, ended up selling my old one

Had a 4,000 square foot garage floor in Tulsa last month and my trusty walk-behind just couldn't keep up. Rented a ride-on from the local supplier for the weekend, figured I'd try it once before dropping the cash. That thing floated and burnished like a dream, cut my finishing time by half, and I didn't even need to use the hand trowel for edges because the weight did all the work. Now I'm torn on selling my old unit for scrap or keeping it as a backup, what do you guys run for big pours, ride-on or walk-behind?

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willow_anderson85•3d ago

Warning: that tinted release agent ate my whole driveway pour

Last month I bought a 5 gallon jug of that cheap tinted release agent from a supply house in Tulsa. It looked fine in the bucket, but the color streaked like crazy once I started the broom finish. I had to rip out the whole slab, about 1,800 square feet, and redo it from scratch. The product cost me $80, but the wasted concrete and labor ran past $3,200. Anyone else had tinted release agents do them dirty, or was I just unlucky with that batch?

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avery366•4d ago

Two-pass troweling on I-10 ramp, I was wrong about it for 8 years

Always thought two-pass finishing was a waste of time, just extra labor for no real gain. Then last fall we did a 4,000 square foot ramp section near El Paso and the second pass saved us from a nightmare of bird baths and uneven edges. Foreman Bill swore by it, I finally saw the difference in texture and flatness after the rain test. Anyone else flip on a technique after seeing it on a highway job instead of a pour?

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eric_morgan59•4d ago

Finally admitted the magnesium float wasn't for me after 9 years

I used to think using a magnesium float was the only pro way to finish. Then I helped a crew in Nashville who used a resin float for everything and I couldn't believe how much easier it was to keep a consistent edge. Tried it the next week on a 1,200 square foot garage slab and the surface came out flatter than anything I'd done with mag. Anyone else stuck on a tool just because older guys swore by it?

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eric_morgan59•6d ago

Hand troweling vs power trowel on a 2k sq ft slab

Did a warehouse floor in Fresno last week, did one half with a power trowel and the other by hand to save time. The power trowel side came out way flatter, no washboard marks even with the 3/8 slump. Anyone else stick to hand work on smaller pads, or am I just wasting hours?

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the_taylor•7d ago

Helping a new guy on a slab in Austin, he asked me something I still think about

Last month I was finishing a 400 square foot patio and this kid fresh out of trade school kept hovering, so I let him run the bull float for a bit. He looked at me and asked, "How do you know when it's time to stop troweling without guessing?" I told him it's about watching the bleed water and how the surface acts under your boots, then I asked him what his instructor told him. Anyone else get these questions from rookies that make you rethink your own process?

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rose_murray•9d ago

Rented a helicopter trowel for a garage pour, never going back

Small garage slab in Columbus last Saturday, about 450 square feet. I've always hand floated and finished with a bull float, takes a solid crew of three to keep up. Rented a ride-on helicopter trowel from the local shop for $180 a day. Night and day difference, the surface came out flat enough to use a laser level on. My buddy Mark watched me finish the whole thing solo in under two hours and just shook his head. Has anyone else tried renting one for residential work, or is that overkill for most of you?

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jake_mason30•11d ago

Blew out a 4 inch slab edge last Tuesday in Phoenix

Had a driveway pour go sideways when the form stakes pulled loose on the west side, the mud ran out before we could screed it flat. Took us 2 extra hours to patch and re-pour that section, and the homeowner watched the whole thing from his kitchen window. Anyone else had form failures mid-pour and found a better way to lock stakes into desert soil?

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lilyrodriguez•17d ago

Replacing my bull float with a truss float changed my finish game in Phoenix

After 12 years of using the same bull float, I switched to a truss float on a 2,400 square foot driveway last month, and the flatness difference was night and day. Has anyone else made that switch, and did you have to adjust your troweling timing afterwards?

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amy302•17d ago

20 years of floating slabs and I just caught my magnesium mistake

Been finishing concrete since 2004 and last month on a driveway in Toledo I finally watched another finisher work a wet edge with a mag and it hit me like a brick. I was always pushing the mag in a circular motion when the surface started to close up. That just spreads the cream around and makes it blotchy. The guy showed me to pull it straight back in long passes and it locks the surface down way more even. I felt dumb as hell standing there in my own driveway watching him work. Has anyone else had a basic move they did for years until someone showed them different?

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nathanking•19d ago

Moved from a walk-behind trowel to a ride-on for a big slab, still not sure I made the right call

We had a 12,000 square foot warehouse floor job down in Tulsa last month and I made the call to rent a ride-on power trowel instead of sticking with my old walk-behind like I normally do. The ride-on definitely covers ground faster, I'll give it that, but the learning curve was steeper than I expected. I've been finishing concrete for about 8 years and I thought I could hop on and just go, but honestly I was fighting the machine for the first hour or so. The finish came out okay in the end, the contractor said it looked good, but I kept catching myself overworking the edges because I couldn't feel the slab the same way. I'm wondering if I should just bite the bullet and buy a used ride-on or if I should stick with the walk-behind for smaller jobs and only rent when it's a huge pour. Has anyone else made that switch and actually gone back to the walk-behind?

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finleybutler•20d ago

That GC's comment about rebar made me question everything I do

Had a site super in Omaha last Thursday tell me my rebar chairs were fine for the spec, but he wouldn't be walking on it with his crew. Said he watched a slab peel apart at a school job up in Council Bluffs because nobody tied the laps right and the trucks came too slow. Hit different because I've been doing pads for 12 years and never really sweat the tying pattern, just the spacing. Anyone else ever get a pass from an inspector and still worry you're leaving a weak spot for the next guy?

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evan51•22d ago

Used to hand float everything, now I run a power trowel for flatwork only

For about 8 years I did all my residential slabs with a hand float and a magnesium trowel. Took forever, especially in July heat around Phoenix. Last spring I borrowed a buddy's 36 inch power trowel for a 1,200 square foot garage pour and never went back for big flat areas. Now I still hand finish edges, steps, and anything under 200 square feet, but anything bigger gets the machine. Anyone else split it that way, or are some of you guys still doing it all by hand on purpose?

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jordangibson•24d ago

A roof inspector in Phoenix made me see slump tests different

Last week we were pouring a driveway and this old roof inspector just stood there watching us. After we pulled some cylinders he walked over and said he always checks slump before trusting any pour because he once saw a slab fail in Tucson from overwatering the mix. That hit different because I used to treat slump as just a formality to get through. Now I actually pay attention to when the load arrives versus when we start pulling, the clock matters more than I thought. Anyone else change how they handle testing after someone outside the trade said something simple?

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thomas_johnson35•26d ago

Overheard a homeowner say our work was 'just pouring dirt'

I was grabbing rebar at the yard in Tulsa last Tuesday and this older guy in line tells his buddy that concrete work is just pouring dirt and waiting. I didn't say anything, but it got me thinking about how much finishing skill goes into a flat slab. Leveling, timing the cream, knowing when to hit it with the bull float, that's the difference between a driveway that cracks in 2 years and one that lasts 20. Anyone else run into folks who think this trade is all labor and zero craft?

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bailey.sandra•27d ago

Watched a crew pour a slab in Tucson and it changed how I finish

I was killing time near a strip mall off Oracle Rd last week and saw a 4 man crew pour about 2,000 square feet. They were using a laser screed, which I never tried, but the thing that got me was how they kept a wet burlap line near the edges the whole time. I always wait until the bleed water dries, but they started troweling the perimeter at like 45 minutes while the middle sat. Has anyone else tried that staggered edge method or am I just old school?

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the_ben•27d ago

My 6x6 pad cracked right down the middle after 2 weeks in Phoenix

Poured a 6x6 patio slab outside Scottsdale, 4 inches thick with fiber mesh and 3/8 rebar on 12 inch centers. Cured it with a misting hose every morning for 5 days. Day 12 a hairline showed up, by day 14 it was a full crack from one edge to the other. Looks like the ground underneath wasn't compacted enough, we had a big rain last month that washed out some fill. My question is, can I epoxy inject this and call it good, or should I bust it out and redo it? Has anyone saved a slab that cracked this fast?

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reeseanderson•1mo ago

Caught a county inspector whispering about a 4 inch slope on a driveway in Phoenix

He said they've been letting 2 inch passes slide for years but someone new is cracking down now, has anyone else run into that issue on residential jobs lately?

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wendy_clark•1mo ago

Question about fixing a 20 year old walkway that just kept cracking

I spent all day Tuesday trying to patch a residential walkway from the 90s and every time I thought I had it sealed the old concrete just spiderwebbed on me again. Turns out the base was never compacted right and I had to rip out a 12 foot section just to get to the root of it. Has anyone else dealt with a pour that just refuses to stop moving after all these years?

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josephb35•1mo ago

Old parking garage in Charlotte had some wild concrete work

I was down in Charlotte last month checking out a job bid and walked through a parking garage built back in '78. The joints were spaced way further apart than I'd ever use, and there were cracks running all over the place but no major failures. Anybody else run into old slabs that somehow held up fine despite going against what we'd do now?

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lilyt90•1mo ago

Showerthought: That concrete curing blanket I used last week might not be doing much

I was reading a study from the Iowa DOT website that said some cheap curing blankets only keep the slab within 10 degrees of ambient, not the 50-70 F you need for proper hydration in cold weather. My last pour in February had a 4-inch slab that barely hit 45 F under the blanket according to my temp gun. Anyone else ever actually monitor their slab temp during cold weather pours, or am I overthinking this?

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fiona_murray•1mo ago

Pro tip: Keep a hose handy when the sun hits your fresh slab wrong

I was finishing a driveway in Phoenix last July and the mix started setting way faster than I planned. The sun was baking one end while the other was still wet, so I grabbed the hose and misted the high spots to slow it down. Worked like a charm but I had to babysit it every 10 minutes for the next hour. Has anyone else had to fight rapid set like this on a hot day?

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the_viola•1mo ago

Switched to a heavy broom finish on my last driveway job and it made a huge difference

I always used a light broom before, but on a 400 square foot driveway in Austin last month I went with a stiff bristle push broom instead. The texture grabbed better in the heat and the customer actually called to say the slip resistance felt way safer. Has anyone else noticed a difference with heavier brooms?

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amy_reed79•1mo ago

Spent 2 hours trying to fix a trowel mark on a wet slab in Denver

I was finishing a small patio job near downtown Denver last Thursday and got this ugly trowel mark right in the middle of the slab. Tried feathering it out with a magnesium float for what felt like forever, but the concrete was already setting up too fast. Finally broke down and used a steel trowel with a bit of water mist, and it smoothed out in like 5 minutes. Anyone else fight with marks this long before giving up?

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