c/concrete-finishers

A guy at the hardware store said I was crazy for using a magnesium float on a driveway pour

He insisted a wood float was the only way to get a proper finish. This was last Tuesday at the contractor desk in Louisville. What's your go-to tool for a standard residential driveway?

2 comments

joseph448•2d ago

PSA: My new magnesium float cracked clean in half on a driveway job in Spokane last Thursday.

The handle snapped right off at the neck when I put some pressure on it, and I had to finish the last 400 square feet with a backup steel trowel, so has anyone else had this happen with a magnesium float from a certain big box store brand?

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maxm50•3d ago

PSA: I added a cup of sugar to a 3-yard driveway mix on a hot day and it set up way too fast.

It was 95 degrees last Thursday in Phoenix, and an old guy at the yard said a bit of sugar would slow the cure. I figured a cup for a small job was safe. Wrong. The stuff went from wet to stiff in maybe 20 minutes. We barely got it edged and floated before it locked up. I learned that 'a bit' is more like a quarter cup, max, and only in a real pinch. Has anyone else had a sugar experiment go sideways like that, or is there a better trick for extreme heat?

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robin_foster1•5d ago

Saw a crew in Boise using a power trowel on a slab that looked way too wet

They were leaving deep ruts and I'm pretty sure that surface is going to craze badly. When do you all think is the right time to bring the machine on?

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wesley_grant33•6d ago

Remember when everyone used those cheap plastic trowels for edging?

I used to think they were fine until I bought a proper magnesium one for a job in Phoenix. The difference in how it glides and holds its edge is crazy, especially on hot pours. That plastic junk would warp and leave marks after a few uses. Anyone still using the old plastic ones or did you all switch over too?

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karenw23•6d ago

Unpopular opinion: I see way too many crews rush the bull float on a hot day just to get to the edging.

Letting that bleed water come up fully before you touch it, even if it means waiting an extra 20 minutes on a 90-degree pour, is the difference between a surface that dusts in a year and one that holds up.

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jade271•7d ago

Question about those new fiberglass trowels everyone was hyping up last year

I bought a 14 inch one from a trade show in Louisville, cost me about $85. For months I kept it in the truck thinking it was just a gimmick. Used my regular steel trowel on a big patio pour instead. Finally tried the fiberglass one on a small shed slab last month because my arm was sore. Honestly, it felt way too light and I thought it would chatter. But the finish came out glassy smooth with half the effort. I'm still not convinced it's better for every job, but I was wrong to write it off completely. Anyone have a take on when fiberglass actually makes sense versus just sticking with steel?

2 comments

barnes.brian•7d ago

I finally got a smooth finish on that crazy sloped driveway in Phoenix

The slope was so steep the concrete kept sliding down, and I had to keep reworking it with my magnesium float for almost four hours before it set right. We ended up using a rapid set mix and a spray-on retarder just to buy enough time. What's the longest you've ever fought with a pour that just wouldn't behave?

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the_river•7d ago

Tried a new spray-on curing compound versus the old plastic sheet method on a garage slab last week.

The spray gave a much more even cure with no wet spots or weak lines, and the finish stayed a perfect gray. What's your go-to method for a small job like that?

3 comments

jade271•8d ago

Just realized I've poured over 500,000 square feet of flatwork in my career.

I was cleaning out my truck and found a stack of old job tickets from the last eight years, so I sat down and added it all up. That number hit me hard because I remember being a green helper and thinking a 2,000 sq ft garage slab was huge. How do you guys even begin to track your totals, or do you just keep your head down and work?

2 comments

grantthomas•9d ago

Pro tip: Always check the forecast before you start a pour, even if the sky looks clear.

I was finishing a patio in Denver and a surprise thunderstorm rolled in halfway through the pour. We had to scramble to cover the slab with plastic and it still got a little pitted. What's your go-to move when the weather turns bad on a job?

3 comments

elliotl24•10d ago

A guy on a site in Boise said my broom finish looked like a 'nervous chicken' and told me to slow my sweep speed by half.

Honestly, I cut my speed and focused on keeping the broom handle at the same angle for the whole pass, and the next 20 square feet came out way more even, so has anyone else had a simple tip that fixed a finish you thought was fine?

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the_jennifer•15d ago

Got caught in a sudden downpour during a pour for a patio in Portland...

We were about halfway through a 20 yard pour for a backyard patio when the sky just opened up. The rain was coming down so hard it started washing the cream off the surface before we could even start floating. I yelled for the crew to grab every tarp and sheet of plastic we had in the truck, and we basically threw a giant cover over the whole slab. We waited under the eaves for about 45 minutes until it slowed to a drizzle, then pulled the covers and hit it hard with the bull floats to work the surface back together. Anyone have a good trick for dealing with rain when you're already committed to a pour?

2 comments

maxm63•15d ago

A guy in Denver showed me his trick for cold joints

I was working a big pour for a driveway last fall and saw this older finisher, maybe in his 60s, prepping the edge of the old slab. He told me, 'Kid, forget the glue. A slurry of pure cement and water, brushed on right before the new mix hits, bonds like family.' I tried it on the next section and the joint was invisible after floating. Anyone else use this method instead of commercial bonding agents?

2 comments

the_hugo•16d ago

Got told my broom finish was too rough for a patio, now I use a different method

I was finishing a patio in Eugene last fall and the homeowner said it felt like sandpaper underfoot. I always used a standard push broom and thought that was just how a broom finish was. He was really polite but firm about it. So I switched to a finer horsehair broom and started pulling it instead of pushing, with a lighter touch. The texture is way smoother now, almost like a light stucco. Has anyone else had to adjust their broom technique after getting feedback?

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kai_west•16d ago

Had to finish a patio in a real tight spot, tried something dumb with a pizza box

Was doing a small backyard job in Tacoma, the homeowner wanted a slab right up against their fence. Could not get a power trowel or even a hand float into the last 6 inch gap. My helper joked we needed a tiny trowel, so I grabbed the empty pizza box from lunch, cut a stiff piece of the cardboard, and used it like a mini darby. It actually worked to smooth that strip without messing up the edge. What's the weirdest tool you've had to use in a pinch?

3 comments

harper_singh•23d ago

PSA: The new city hall plaza in Springfield has the worst expansion joint work I've ever seen.

I was walking through there last week and the cuts are all over the place, some are way too deep and others barely scratch the surface. It looks like they let an apprentice go wild with a saw for the first time. How does a job that big get signed off with such sloppy control joints? Anyone else seen a public project this bad lately?

2 comments

maxm63•24d ago

Pro tip: I finally figured out why everyone's broom finish on sidewalks looks so weak after a winter.

I was convinced a light pass was fine until my foreman in Minneapolis showed me how pressing the broom down for a full 3 seconds per pull creates deeper grooves that actually hold up against salt and freeze-thaw cycles.

2 comments

dylanwilliams•24d ago

A retired finisher in Spokane told me he always adds a cup of sugar to his wash water for cold weather pours.

He said it keeps the surface from freezing before the set, and I tried it on a garage floor last November. Has anyone else tested this old trick?

3 comments

finley_lopez98•24d ago

Pro tip: I stopped using a power trowel on every single pour and it saved a job in Memphis.

We were finishing a 40 yard driveway slab last spring, and the mix was coming in really wet. My partner fired up the power trowel right away like we always do. I saw it start to pull up water and leave a rough, open surface. I told him to shut it off and we hand-floated the whole thing first to push the cream up. It added an hour, but the finish was perfect. When do you guys decide to skip the machine and go straight to hand tools?

2 comments

andrew_kelly•24d ago

Rant: I was overworking my bull float for years on garage slabs

A foreman in Omaha pointed out my passes were too slow, trapping air instead of pushing it out. When did you guys figure out the right float speed?

2 comments

elizabethg53•25d ago

PSA: An old timer told me to use a garden sprayer for curing and I should have listened

I was doing a 20x30 patio in July and my boss said to just hose it down twice a day. This old guy named Ray, who used to run his own crew, saw me and said to get a pump sprayer and mist it every few hours for the first two days. I ignored him, thinking it was overkill. Sure enough, we got some fine surface cracks from it drying too fast in the heat. Ray was right, the constant light misting keeps the surface temp down and the cure even. Anyone else have a simple trick they learned the hard way?

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derek_dixon78•25d ago

Just realized adding a splash of dish soap to the curing water on a stamped patio in Tucson made the colors pop way more than the sealer we usually use.

Honestly, the homeowner's wife suggested it as an old trick, and now I'm wondering if we've been overcomplicating the finish for years or if this is a fast track to efflorescence problems down the road.

2 comments

kelly.felix•26d ago

Tried a magnesium float versus a steel one on a 30-yard pour last Thursday.

The magnesium gave me a much smoother finish on that warm morning, but does anyone have a trick for when the concrete starts setting up too fast?

2 comments

the_amy•26d ago

I used to think power trowels were just for big crews until I tried one on a 400 sq ft garage floor

For years, I stuck with a hand trowel for everything under 1000 square feet, thinking a power trowel was overkill and a hassle for small jobs. My buddy in Phoenix kept telling me I was wasting time and energy. Last month, I had a single-car garage pour, about 400 square feet, and decided to rent a Whiteman walk-behind just to shut him up. I was sure it would be too aggressive and mess up the finish. Man, was I wrong. It cut my finishing time in half and gave me a way smoother, more even surface than I could get by hand, even on my knees. The control was fine enough to handle the edges without issue. Now I'm rethinking my whole approach to small slabs. For those of you who do a mix of big and small jobs, do you use a power trowel every time, or do you still draw a line somewhere?

3 comments