c/concrete-finishers

18

reesea49•2d ago

Warning: That blade oil hack ruined my finish

I saw a bunch of guys online saying to spray wd-40 on your trowel blades to keep the concrete from sticking during hot weather. Tried it on a driveway pour in Phoenix last August, about 95 degrees. The concrete was setting fast so I figured it would help. Nope. The oil left weird dark splotches all over the surface that didn't fade even after curing. Owner had us grind it down and reseal, cost me $400 in time and materials. Learned my lesson: stick to plain water on the blades if you need anti-stick. Has anyone else had a bad result with oil-based stuff on fresh concrete?

3

anderson.david•3d ago

Drove by a new subdivision in Phoenix and noticed all the driveways had control joints cut way too deep

I was passing through a new build neighborhood near Surprise, Arizona last Tuesday, and every single driveway had control joints that looked like they were cut nearly half the slab depth. A couple of them already had small cracks running from the joint corners after just 3 months of curing. Has anyone else seen this issue with contractors going overboard on joint depth lately?

20

joseph_torres•4d ago

Debate: Wet cure vs. seal and forget for driveways

I had a debate with a guy in Denver last week who swears by soaking burlap for 7 days straight, says it prevents all surface cracking. But my crew in Phoenix just sprays on a curing compound and walks away - no issues in 3 years. Which method holds up better in your experience - long wet cure or just sealing it?

8

hannahk19•6d ago

Vent: That broom finish I did last August looked terrible after the first freeze

I used a cheap magnesium float and the surface came out way too rough, then water got into the pores and spalled off 3 months later in Denver. What trowel or float are you guys using for a smooth broom finish that actually holds up?

28

the_thomas•7d ago

Tried a power trowel on a small slab last week and it was a disaster

Figured I'd save time on a 4x6 patio in Austin but ended up spending 3 hours fixing the gouges it left behind - has anyone else had better luck with those electric edgers for tight spots?

5

williams.kim•11d ago

Tried wetting my forms the night before a big pour and it actually helped

Had a 20 yard driveway pour last month here in Phoenix where the sun was beating down and I kept getting edges drying out way too fast on me. An old finisher I know told me to hit the forms with a garden hose the night before so the wood would soak up moisture and not pull water out of the concrete. I was skeptical but figured what the heck and tried it on half the forms as a test. The wetted side stayed workable way longer during finishing while the dry side was already crusting up around the edges. Did any of you guys grow up learning this trick or did I just miss out on some basic knowledge?

15

brown.gavin•11d ago

Warning: Picked rebar over fiber mesh for my last driveway pour

I had to choose between fiber mesh and traditional rebar for a 40-yard residential job last month. Went with the rebar even though the fiber was cheaper and easier, and now I'm glad I did because a corner of the slab is already showing hairline cracks a week later. Anyone else had fiber mesh fail on them in high traffic spots?

5

nancy_ross•13d ago

Old foreman Jerry told me to wet cure for 7 days no exceptions

Back when I started finishing 15 years ago in Phoenix, my foreman Jerry was adamant about wet curing every slab for a full week. He said skipping it would cost me down the road. I thought he was being old school and over cautious. Last summer I poured a small patio for a client and got lazy, only misted it for 3 days before moving on. Within 6 months there were hairline cracks all over the surface from the heat and dry air here. Jerry was right all along. Now I soak burlap and keep it covered for the full 7 days no matter what the schedule says. Has anyone else learned this lesson the hard way in a dry climate?

2

finley729•13d ago

Am I the only one who thinks wet curing is overrated for small residential jobs?

I swear everyone in here swears by wet curing for everything. But I did a 4x6 patio slab in Spokane last summer and just used a decent curing compound spray. After 8 months, no cracks, no dusting, and the customer was happy. Wet curing is a hassle on small pours. Has anyone else had good luck without it?

17

jesse994•15d ago

Took the gamble on a cheap power trowel instead of renting a name brand for my 3,000 sq ft garage slab job in Tulsa. The blades wobbled by the 4th pass and I spent a whole afternoon with a hand float fixing it.

I figured I'd save $150 on the rental fee by buying a sub-$400 model from a big box store. The first 15 minutes were fine but then the vibration got bad and I could see the finish going uneven. Ended up having to hand finish almost the whole thing. The cured slab looks fine now but I lost 4 hours I didn't plan for. Anyone else talked themselves into buying cheap gear and then regretted it mid-pour?

30

allen.ivan•17d ago

Appreciation post: That old broom handle trick for avoiding knee grooves

I was on a job out in Snohomish last week and an older finisher showed me how he uses a broom handle laid across the wet concrete to kneel on without leaving divots. It sounds so simple (and probably obvious to some of you), but I've been using boards and they always slip or leave marks. He just sets the handle down, kneels on it, and moves it along as he works. Has anyone else got a weird little trick like that you picked up from a random guy on a jobsite?

1

blakem37•19d ago

Tried a new concrete sealer on my driveway last month and it turned into a mess

I picked up a bottle of that acrylic sealer from Home Depot for about $40, figured it was the same as what I used back in the 90s. Put it on a 400 square foot driveway in Cincinnati, and the stuff turned cloudy after one rain. Turns out they changed the formula and now you have to apply it in perfect weather or it traps moisture. Anyone else had trouble with the newer sealers?

16

evan_burns95•20d ago

Burned $200 on a cheap power trowel from a big box store

Picked up one of those off-brand power trowels from Lowe's back in March for like $180 because I figured it'd save me some elbow grease on small garage slabs. First job went okay but by the second pour the clutch started slipping real bad and the handle vibrated so much my hands went numb. Took it back and they wouldn't refund it because I didn't keep the receipt and it was past 30 days. Ended up having to buy a used MBW from a buddy for $350 and that thing runs like a dream. Any of you guys ever get burned by those cheap rental-grade tools?

8

emery_young13•20d ago

The painter who told me to slow down on a driveway in Ohio

I was finishing a big residential driveway just outside Cincinnati last fall, running about 30 yards of gray mix. This old painter who was working on the house next door walks over, watches me for a minute, and says 'you're fighting the cream, not working it.' I had no idea what he meant at first, but he showed me how I was dragging my float too hard and bringing up too much fines. Has anyone else had a total stranger give them a tip that actually stuck with you?

2

riley_taylor•20d ago

Appreciation post: that one Tuesday where everything clicked on a 40-yard pour

Last spring I had a Tuesday that was just unreal. We were doing a 40-yard driveway pour off Baseline Road and the mix was perfect, the weather was 72 and overcast, and my crew hit every joint clean. Normally I fight with bull float lines or have to redo a edge, but that day the concrete just behaved itself. Finished up by 2 PM with zero patches needed. Has anyone else had a day where the concrete gods just smiled on you?

20

sam_murphy39•22d ago

Old timer told me to wet the subgrade before pouring. I ignored him.

Last summer on a job in Phoenix I skipped wetting the base. Thought it would save time. Ground was bone dry. By day two the slab had cracks near the edges. Took me three patches and a pissed off homeowner to learn my lesson. Anyone else get burned ignoring the basics?

11

troy832•22d ago

My old bull float vs the magnesium one I finally bought

I ran a float with a wood handle for probably 15 years. Swore by it. Then I grabbed a magnesium float from a supply house outside of Nashville three summers ago. That first pass on a slab felt completely different. The metal just glides and I was getting a way smoother surface with way less arm work. Took me way too long to switch. Has anybody else made a similar switch and felt the same?

20

adamgreen•22d ago

Just read that concrete curing can increase strength by 50% - is that right or hype?

I was flipping through an ACI guidebook at our supply yard yesterday (while waiting for a load) and saw a stat that said proper moist curing can boost compressive strength by up to 50% compared to letting it dry out fast. That blew my mind because I've always just wet the slab down and covered it with plastic, nothing fancy. But then I got to wondering - is that 50% number real for everyday flatwork like driveways and patios, or is it more for lab mixes with strict controls? Has anyone here actually tested pours where they did a full 7-day wet cure versus just letting it be?

19

jessica_hall49•26d ago

Was prepping a slab last week and an old timer walked up and said 'you're drowning it'

I was pouring a 12x16 patio in Austin last Tuesday and this guy in his 60s just comes over and watches me run the bull float. He goes 'son you're drowning it, let the water come to you not the other way around.' Stuck with me because I was literally fighting the bleed water instead of letting it do its thing. Anyone else had a random stranger drop some wisdom on a job that actually made you change how you work?

8

blakem37•27d ago

That two-day pour in Phoenix last July nearly broke me

We had a 120 yard driveway going in, and the temp hit 115 both days with the sun just baking everything before we could finish. The mix started setting up in the truck before we even got it down, and we had to work like crazy to keep edges from curling. Has anyone else dealt with rapid set issues in extreme heat and found a mix additive that actually buys you time?

7

hernandez.finley•28d ago

Poured a driveway last spring and it looks completely different now

Laid a 30 foot driveway in April with fresh concrete and a broom finish, and by August it started getting these weird dark patches near the edges. Turned out I didn't wet cure it long enough because the weather got hot fast, so the surface dried unevenly. Anybody run into this and fixed it with a sealer or did I mess up the mix itself?

18

the_nina•1mo ago

Saw a crew in Austin skip mud curing on a hot day and learned my lesson

I was on a job site in Austin last August watching a crew pour a driveway in 95 degree heat. They sprayed cure compound but skipped the wet burlap and poly, and within 3 hours the surface was checking like crazy. Has anyone else seen guys skip proper curing and end up with a mess?

15

nancygrant•1mo ago

I noticed a big difference in slab finishes after switching from a magnesium float to a resin one

After 6 months of using a resin float on my commercial jobs around Springfield, the surface density and lack of bug holes is way better than the years I spent with magnesium, but I hear some guys say resin leaves too slick a finish for outdoor work, so what's your take after trying both?

5

lane.eric•1mo ago

That quikrete mix at the Memphis jobsite almost cost me a pour

Last Tuesday we were pouring a 30x40 slab at a warehouse off Lamar Ave in Memphis. The batch yard sent out 7 yards of quikrete 4000 that just looked wrong when it came off the truck, too dry and crumbly. My finisher buddy Tim said 'that mix ain't right' and we sent it back before we even touched it down. Turned out their water meter was off and we would have had a brittle slab that cracks within a year. Anyone else run into bad loads from a yard you usually trust?

14

dakotawood•1mo ago

I finally saw how bad our sealer job was after a year of weather

We did this big stamped patio in Phoenix about 14 months ago and used that solvent-based acrylic sealer the boss always pushes. Drove by the other day and the color was completely faded in spots and it's peeling up near the edges. Is there a way to strip this stuff off without damaging the color underneath?