c/concrete-finishers

Old parking garage in Columbus still has the best broom finish I've seen

Went to pick up parts downtown last week and that 1970s garage on 3rd Street has a broom finish that puts most of today's work to shame. No sealer, just straight concrete, and you can still see the pattern clear as day after 50 winters of salt. Anybody else got a spot they drive by and can't help but study the flatwork?

Powder vs liquid hardener, changed my mind after 12 years

I've always used liquid hardener because that's what my first boss taught me back in Fort Worth. Last month a supplier gave me a free bucket of powder to try, and I figured it was just marketing fluff. But after running it on a 2,400 square foot warehouse slab, the finish came out denser and the dusting was almost zero compared to my usual mix. Still torn on whether it's worth the extra time to broadcast it by hand, or if I'm just lucky with the weather that day. Anyone else switch and stick with it, or go back to liquid?

Saw a parking garage pour in Phoenix that made me question my bull float technique

I was in Phoenix last week for a cousin's thing and walked past this deck pour they were finishing. The crew was using a ridged bull float and doing these long, slow sweeps that just looked different than how I usually run mine. I watched for maybe 20 minutes, and the cream they were pulling up had almost no drag lines, even in the afternoon heat. I asked one of the finishers about it, and he said they switched from a magnesium float to a resin one on sunny days because it doesnt grab as much when the surface starts to set. I tried the same idea on a small patio slab back home yesterday, and I'll be honest, it gave me a flatter finish with less effort. Has anyone else messed with float material depending on the weather, or is that just a desert thing?

My power trowel died mid-pour on a 40-yard slab in Phoenix last Tuesday

Ran across a stat that the average concrete crew wastes about 4% of every yard they pour

Saw it in a trade magazine in a truck stop in Wyoming last week and it got me thinking about all the mud I've left on the ground over the years. Anyone else ever track how much they actually lose per job?

Old foreman told me to wet the subgrade before pouring...

He said it'd keep the slab from cracking, but I tried it on a 30 yard pour down in Tucson and the whole thing turned into a muddy mess... any other finishers ever run into this?

Hit 500,000 square feet of flatwork last month and nobody cared

I keep track of every slab I pour. Last month I crossed half a million square feet since I started keeping records back in 2012. Told my foreman about it and he just said cool, can you finish that sidewalk by noon. Got me thinking about how we measure our own progress. Anyone else keep a running tally of their work or am I the only weirdo with a spreadsheet?

Saw a crew at a county job in Ohio skip the expansion joints and I'm torn on whether it's a time saver or a future crack guarantee

They poured a 40-foot driveway last Tuesday with no relief cuts and the foreman swore it was fine on compacted gravel base, but my gut says they'll be back for saw cuts within 6 months, so what do you all do when the weather's cool and the ground's stable - do you still cut every 10 feet or trust the mix?

I used to swear by rapid set cement for small patch jobs, but now I think it's overrated

Gave it another shot last week fixing a curb in Denver and the stuff cracked within 48 hours. Standard portland mix with some fiber reinforcement has held up way better on my past three repairs. Anyone else ditch the fast stuff for regular mix on small jobs?

Made the switch from hand troweling to power trowels on flatwork and I'm never going back

I fought it for like 5 years because I thought power trowels were just for big crews and lazy finishers. Finally rented a 36 inch ride-on for a 4000 square foot warehouse slab in Akron last month. The difference in density and flatness was insane - we did in 3 hours what would have taken 12 with hand floats. My knees and back are thanking me too. Only downside is you gotta watch the corners still, you'll always need a hand float for those tight spots. Anyone else make the switch later in their career and feel stupid for waiting so long?

Tried a magnesium floor hardener on a garage slab last week

Had a guy pour a 30x40 garage and wanted it super dense. Mixed in a gallon of lithium hardener additive. Brought my burnisher back after 4 days and that floor rang like a bell. Any of you guys use additives to boost surface density on residential jobs?

I still think about that pour we did in 2007 in Cleveland

Back in 2007 me and my old crew did a big warehouse floor over in Cleveland. The concrete we used back then was different, it felt heavier and took longer to set up. We had to hand trowel the whole thing over two days because the mix was so stiff. Now I see these super fluid mixes that go down in a few hours with power trowels. The finish we got back then had a slightly rougher texture though, almost like it had more character. You could see every pass of the trowel if you looked close. These days everything comes out so flat and shiny it almost looks fake to me. Has anyone else noticed the old concrete seemed to hold up better against salt and weather over time?

Heard a homeowner say concrete is just gray dirt that gets hard

I was grabbing coffee last Tuesday before a 7am pour and this guy in line tells his buddy concrete is just gray dirt they let dry out. I wanted to turn around and explain curing, mix designs, and why his patio cracked in 6 months. Any of you ever had to bite your tongue when someone completely misses what we actually do?

Hot take: that 10 year old concrete driveway I resurfaced last month

I had this old driveway in Phoenix that was cracked and pitted from years of sun. Ground it down, patched the deep spots with a high-bond mix, then put down a thin overlay. The owner had me match the original broom finish and it came out looking like new. Has anyone else tried resurfacing older slabs instead of tearing them out - how long did yours hold up?

Spent 2 years using too wet of a mix on my slabs and wondered why I kept getting cracking near the edges

A old timer at the ready mix plant finally told me to back off the water by about 2 gallons per yard and my last driveway pour didn't have a single hairline crack along the forms has anyone else been running wetter than they should and only realized it after someone called them out?

Why does nobody talk about hand troweling vs power troweling for small slabs

I did a 300 sq ft patio last month near Austin and used a power trowel like usual. Came back two weeks later and the edges were cupping bad. Redid it with a hand trowel and magnesium float and the finish came out way flatter. Has anyone else seen power trowels mess up smaller pours like that?

The old trick for fixing honeycomb that I stopped using

I used to patch honeycomb spots on walls with a dry mix and a rubbing stone. It worked okay but took forever and looked rough half the time. About 2 years ago I switched to using a slurry of cement and water brushed into the voids before the final set. It bonds way better and the finish matches the surrounding concrete almost perfect. Now I only patch dry if it's a tiny nick smaller than a dime. Anyone else find a better way to deal with honeycomb on vertical pours?

Hit 1,000 square feet of broom finish in a single pour last Tuesday

That's a personal record for me on a residential driveway. I usually top out around 700 with hand tools before my back gives out. But I had a helper who actually knew how to handle the hose and we just kept moving. Some guys I know push for machine finishing on anything over 500 feet and say I'm wasting time. They might be right for speed, but I think broom finish looks better on driveways. What's your cutoff for calling in a power trowel crew versus just doing it by hand?

Tried a power trowel on a small patio pour and it went way better than I thought

I usually hand finish small residential jobs but this 12x16 patio in Austin needed to be done quick before the heat set in. Rented a 36 inch power trowel from Sunbelt and ran it after the bull float and it flattened like butter. Cured up real smooth with no chatter marks. Anyone else use power trowels on tiny pads or is that overkill?

Found a trick for bull floating big slabs at the Johnson job site

We were pouring a 60x40 pad for a warehouse last Thursday and I was fighting with the bull float like crazy. Old timer named Mike came over and told me to wet the float first and keep a spray bottle handy. It made the whole finish so much smoother, no sticking at all. Anyone else do something simple like that that just clicked one day?

Vent: Discovered the hard way that poly fiber in mix causes cold joints

I tried adding polypropylene fibers to a driveway pour last month to cut down on cracking, but it actually made the concrete set way faster than I expected. Ended up with a cold joint right down the middle because I couldn't finish the second batch in time. Has anyone else run into this issue with fibers messing up your timing?

I finally stopped listening to that old-timer about curing time

Met a guy named Ray on a job in Tulsa back in 2017. He told me to wet cure for 14 days minimum or the slab would dust forever. I followed his advice for years. But then I did a 3000 square foot warehouse floor with a curing compound instead. Three years later, zero dust issues. Ray was wrong. Has anyone else dumped old rules that turned out to be nonsense?

Finally figured out why my concrete kept cracking near the expansion joints

Watched a guy on a job in Phoenix 2 weeks ago spray the joints with water right before the pour and I realized I was letting them dry out too fast. Anyone else ever miss something this basic after years in the trade?

I finally hit 10,000 square feet in one pour without a single cold joint

Been finishing concrete for about 8 years now and last Tuesday I did a 10,000 square foot warehouse slab with my crew. We had 4 guys and a power trowel running nonstop for 14 hours. The mix had a retarder in it which bought us some time but I was still nervous about the edges setting up before we could get to them. Everything came out smooth though, no lines or weak spots anywhere. The owner even walked it with a straight edge and said it was flatter than his kitchen floor. Has anyone else tried a longer set time mix on a big pour like this?

Why does nobody talk about using a rubbing stone on fresh concrete?

I always thought it was just an old timer's myth until I tried it on a tricky driveway pour in Phoenix last summer where the finish was looking rough. The difference was night and day, has anyone else had good results with this method?