c/concrete-finishers

Blew out a 4 inch slab in Phoenix last Tuesday

Got a call to fix someone's driveway that had a big crack right through the middle. Chipped it out with a jackhammer and found the base was pure caliche clay. Anyone had luck using gravel base instead of sand in dry climates?

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brian_rivera59•18d ago

Tried a cheap expansion joint trick and it saved my back on a big pour

I was dreading a 40-foot driveway in Austin last Tuesday because cutting those joints by hand always kills my knees. An old-timer told me to try using a 2x4 with a beveled edge pressed into the wet concrete instead of sawing later. It actually gave me clean lines and took half the time, no power tools needed. Has anyone else had luck with this method or is there a better approach for long runs?

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aaron884•18d ago

Took me 5 years to realize I was overworking my concrete with too much troweling

I was out on a driveway pour last Thursday in Austin and my foreman just stood there watching me hit it with the power trowel for the third pass. He finally walked over and said 'you're burning the cream off the top, kid, look at that crust forming.' I had no idea that extra passes were actually drying out the surface and making it weaker. I always thought more finishing meant a smoother look but turns out I was creating dusting issues on my last three jobs and never connected the dots. Now I do two passes max and let the bleed water do its thing. Anyone else get told this late in their career?

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hunt.quinn•19d ago

Spent 4 hours fixing a slab edge that I messed up in 10 seconds with a bad edging tool angle

Took me three tries and a whole bucket of patch mix to realize the curve was fine, I just wasn't wetting the concrete enough before running the tool over it, anyone else get stuck on something this dumb for way too long?

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troy832•22d ago

Wasted $800 on wrong release agent for stamped concrete

Last month I bought a big drum of generic release agent from a supply house I'd never used before. Figured it was all the same stuff, right? Well it turned my color hardener into a muddy mess and the stamps kept sticking even after I doubled the coat. Had to rip out a 400 square foot patio in Peoria and start over. Any of you guys had a bad batch of release agent ruin a job like this?

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dakotawood•25d ago

Learned the hard way why you shouldn't wet cure in direct sun

For about 2 years I always wet cured my garage slabs in July heat here in Phoenix. Last summer I had a 40x30 pour crack all the way across on day three. A older finisher walked by my site and pointed out my curing blankets were bone dry by noon because the sun was cooking the water right off. Now I switch to a liquid membrane curing compound for outdoor work in the summer, saves me the headache.

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alicecooper•26d ago

Talked to an old timer at the supply yard last Thursday

He said he never uses a bull float on colored concrete because it pulls the pigment uneven. Made me think about all the blotchy jobs I fixed that could have been avoided. Any of you guys skip the bull float on colored pours?

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claire_ramirez•26d ago

That $80 Amazon trowel that warped after 3 pours

I bought this fancy magnesium trowel online for 80 bucks last month, figured it was a steal compared to the supply house. After three slabs the blade bowed in the middle and left ripples I couldn't fix. Anybody else get burned by cheap tools or do you stick with a certain brand?

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lane.cameron•1mo ago

Discovered a cheap foam roller trick for fresh slab edges

Ngl I used to fight with hand tools forever trying to get a nice radius on edges after the float. Then a guy on a job in Portland showed me using a 4 inch foam insulation roller dipped in water instead of a regular edger. It leaves a perfect bullnose every time and cuts my finishing time by like 15 minutes per pour. Anyone else try something weird like that for edges?

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cooper.phoenix•1mo ago

Burned through a batch last Tuesday with a bad water ratio

I was pouring a small walkway near Austin last week and got distracted talking to the homeowner. Mixed the water a bit too heavy and the surface turned to dust by the time I floated it. Had to rip it out and start fresh the next day, cost me about 4 hours and a whole yard of mix. Anyone else had a slump get away from them like that?

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diana20•1mo ago

Old timer told me to wet the ground before pouring and I thought he was crazy

Guy named Rick who's been doing concrete since the 80s told me to spray down the subgrade before my last residential slab in Phoenix. I figured it was a waste of time since it was 105 out. But he insisted so I did it and the mud held moisture way longer than any of my other pours. Has anyone else had better results with wetting the dirt first or is this just a desert thing?

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kim819•1mo ago

That $60 power trowel attachment changed my mind on hand finishing

I used to swear by hand finishing everything because I thought machines left too many swirl marks. Then I borrowed a buddy's power trowel attachment for a 400 square foot garage floor last month. It cost me about $60 for the attachment and it cut my finishing time in half. The surface actually came out smoother than my hand work and I haven't gone back since. Has anyone else been surprised by a tool they were skeptical about?

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anna_ross19•1mo ago

Week from hell on a driveway pour near Denver

Last Tuesday we did a 40 yard driveway pour and the concrete started going off in the truck before we even got it in the forms. Had to rush the finish so bad the homeowner called and said it looked like crap. Anyone else had a batch go hot on them that fast?

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oliviagrant•1mo ago

Bought a cheap magnesium float years ago and it's still my favorite tool

I was skeptical when a guy at a supply house in Columbus told me to grab this $12 float over the $40 one. But after smoothing out 500 yards of steps with it last week, I've never had a finish look that clean. Anybody else find a cheap tool that just works better than the expensive stuff?

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adamgreen•1mo ago

Hit exactly 1000 square feet of broom finish in one pour and barely made it

Had a driveway pour last Thursday where we placed 8 yards of mix and I ended up with exactly 1000 square feet of broom finish when I measured it out. That's the most I've ever done solo in one continuous pour without a break. I use a 4 foot mag and a 36 inch broom with stiff poly bristles, and I had to really pace myself on the timing. Anyone else run into a point where their body just gives out after a certain square footage? How do you push past that wall?

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nguyen.tara•1mo ago

Walked past a driveway I did 8 years ago in Phoenix yesterday

The homeowner was out watering and I almost didn't recognize it - the color stayed deep and no spider cracks anywhere. I remember I used a densifier on that one instead of just sealant, guess that made the difference. Anyone else see big differences years later from one product choice?

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lindaowens•1mo ago

I keep seeing guys skip the broom finish on sidewalks and it's a problem

Last week in Tacoma, I watched a crew pour a new walkway and just trowel it smooth. No broom at all. That surface is going to be slick as ice with the first rain. I've seen three slips on a job like that before. Why do people think a slick finish is okay for a public walk? Has anyone else had to go back and fix this for another crew?

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derekjenkins•1mo ago

I used to think a power trowel was overkill for a 10x12 patio

My buddy in Phoenix kept telling me to just rent a 36-inch walk-behind for anything over 100 square feet, but I insisted on doing it by hand for 'better control'. After my arms felt like jelly on the third one last summer, I finally caved and tried his way. The finish was way more consistent and I saved about 90 minutes of work. Anyone else have a specific size where you finally switch to the machine?

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kelly_west74•1mo ago

Just realized I was wrong about magnesium floats vs aluminum for finish work

For years I used an aluminum float on everything, thinking the extra weight gave a better press. Last month on a 40 yard slab for a garage in Spokane, I switched to a magnesium float halfway through just to try it. The difference was huge, the magnesium didn't drag or tear the surface like the aluminum did, especially as the concrete started to set. It left a much tighter, smoother finish with way less effort. I finished that side about 20 minutes faster and the client specifically said it looked better. Anyone else make this switch and notice a real difference on bigger pours?

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hunt.quinn•1mo ago

Remember when we all made fun of those laser screeds?

I thought they were just for big jobs and a waste of money. Then we got a contract for a 10,000 sq ft warehouse floor in Kansas City and rented one for a week. The crew finished the pour and initial screed in half the time, and the floor was dead flat. Now I look at my old straightedges differently. Anyone still using manual screeds for slabs that size, or has everyone switched?

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holly_walker76•1mo ago

I was adding way too much water to the mix for a solid year.

I kept getting hairline cracks in my flatwork, especially on driveways. A guy I worked with in Phoenix last summer watched me pour and said, 'You're making soup, man.' He showed me his slump test on the same truck load, and his mix was way stiffer. I cut my water by about 15% from my old habit, and the next three pours had zero cracks. How do you judge the right workability without going overboard on water?

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josephbutler•1mo ago

Serious question, how do you deal with a bad slump in a driveway pour?

Had a job last week in the old part of town where the ground was way softer than we thought. The concrete truck showed up and we started the pour, but one corner just kept sinking. We had to stop, bring in more gravel, and compact it three separate times. What should have been a 4 hour pour turned into an 8 hour day, easy. Anyone got a good trick for spotting a soft spot before you start?

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riley_schmidt•1mo ago

Just found out from a county inspector that the Roman Pantheon's concrete dome is still the world's largest unreinforced concrete dome, which blew my mind considering it's almost 2,000 years old.

It makes you think about the quality of the mix and placement they achieved back then, so what's the oldest concrete structure you guys have worked on or seen that's still holding up solid?

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thompson.nathan•1mo ago

Rant: I tried a new fast set concrete mix on a small patio job and it was a disaster

Last week I had a 10x12 patio pour in Springfield and decided to try that 'Quick-Crete Pro' mix to save time. I usually use the standard stuff from the local yard. The fast set started to kick in about 20 minutes after we finished the pour, way faster than the 45 minutes we were used to. We barely got the bull float across it before it started to set up hard, and the finish was terrible, full of lines and rough spots. I had to grind down the whole surface the next day, which added 4 hours of work and cost me an extra $200 in rental fees. The time I thought I saved on the front end was totally lost on the back end fixing my mistakes. I'm sticking with the regular mix from now on unless it's a tiny repair. Has anyone else had a bad time with these fast setting mixes on a bigger flatwork job?

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the_tara•1mo ago

I finally listened to the old guy about my bull float technique

He watched me on a garage slab in Tacoma and said 'you're fighting the concrete, not floating it.' I realized I was pushing down way too hard, trying to force it flat instead of letting the tool do the work. Anyone else have a simple tip that fixed a bad habit?

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