c/concrete-finishers

17

butler.brian•2d ago

Old timer at the job site showed me a trick with a broom

I was finishing a driveway in Akron last summer and a guy who's been pouring since the 70s walked up and told me to wet my broom before dragging it. He said dry bristles leave chatter marks that show up after curing, and sure enough my last job had those lines I couldn't figure out. Anyone else ever get advice from a random stranger that actually fixed a problem you were having?

14

the_sean•4d ago

Spent $150 on a fancy power trowel and it paid for itself in 3 days

Tbh I was on the fence about dropping that cash on a new power trowel for months. I finally caved after a big driveway job in Austin last week and man, it cut my finishing time in half. The old one was beat up and leaving swirls everywhere. Anyone else find that spending money on a decent tool made a huge difference on a tough pour?

17

christopher385•5d ago

Figured out why my broom finish was always uneven

For years I used to do my broom finish in one long continuous drag from one side to the other. Then about 6 months ago I watched a guy on a job in Dallas pull the broom in short overlapping strokes instead. He told me it keeps the lines straighter and stops that wavy look you get when the broom slows down halfway across. Next day I tried his method on a 40 yard driveway and the finish came out way more consistent. Has anyone else found that the length of your broom stroke matters more than speed or angle?

7

olivia478•5d ago

Saw a cold joint form right before my eyes on a slab in Denver last Tuesday...

We were pouring a 30x40 garage slab and the truck got delayed by 45 minutes. I figured we had enough time but the heat was beating down hard. The old concrete started setting up faster than I thought. When the fresh mud went down next to it, you could see the line forming where it wouldn't bond right. Had to run a grinder over it later to try and blend it in but it's still gonna be a weak spot. Anybody got tricks for avoiding this when you know a truck is gonna be late?

4

paul_webb45•5d ago

Shoutout to the guy who troweled a wet slab in 95 degree heat

Last summer on a job in Phoenix, this kid tried to finish a slab when the concrete was still sweating. Foreman told him to wait but he went ahead anyway and ended up with a crusty mess we had to grind down the next day. Cost the crew like 4 extra hours and a bag of patch mix to fix his mistake. Anyone else ever seen a hot pour go bad this fast?

19

mason_jackson•6d ago

Saw a video that changed my mind about wet curing

I always thought wet curing was overkill for flatwork. Been doing this 12 years and never bothered unless the spec called for it. Then I watched a guy on YouTube from the American Concrete Institute break down the numbers. He showed that concrete left to dry out loses about 50% of its potential strength in the first week. I ran some tests on a driveway I poured last month in Phoenix where it hits 105. I covered half with wet burlap and kept it moist for 5 days, left the other half to air dry. After 28 days the wet cured side tested almost 1,500 psi higher. That blew my mind. Has anyone else seen big strength differences from curing methods on their jobs?

3

derek_dixon78•7d ago

Appreciation post: Finally figured out why my bull floats were chattering

Been fighting this problem for about six months where my bull float would skip and chatter on wet concrete, leaving these ugly little ridges. I tried everything, different angles, different pressure, even switched to a magnesium float. Turns out I was just putting the float down too fast and at too steep of an angle. Once I slowed down and laid it flat it smoothed right out. Anybody else deal with something stupid simple that took way too long to figure out?

6

mark_hernandez12•8d ago

Took me 4 hours to get a broom finish on a driveway because the mix was too wet from the truck driver adding water on site

By the time I figured out that extra water was the issue, the concrete was already starting to set and I had to work like crazy just to get it passable, has anyone else dealt with a batch plant pushing wet loads late in the day?

22

bell.taylor•8d ago

Changed my mind about wet-curing after talking to an old-timer from Iowa

I bumped into a retired finisher at the supply yard last week who said he never uses curing compound and just soaks his slabs for 7 days straight with burlap and sprinklers. He showed me photos of driveways he did in the 80s with zero cracks, and I gotta admit it hit different seeing that kind of track record. Has anyone else here switched from chemicals back to old-school wet-curing and seen better results?

14

matthewp52•9d ago

Saw a crew using wet burlap on a big slab in Phoenix last week

I was driving past a job site near the 101 and spotted about 6 guys laying burlap and misting it every hour on a 200 yard slab. Stuck around to ask the foreman and he said they do it to keep the cure consistent in the dry heat. Never tried that myself on anything bigger than a sidewalk. How long do you let the burlap sit before pulling it off?

25

matthewp52•11d ago

Heard a foreman say we should stop using burlap for curing slabs

I was on a job site over in Springfield last Tuesday and this old timer foreman was telling the crew that burlap is basically just asking for uneven curing and moisture problems. He said he switched to those poly blankets a few years back and hasn't looked once. I mean, I've always used burlap because that's what I learned on. Anyone else's crew making that switch or is this guy just being picky?

2

bettymurphy•12d ago

Hot take: a magnesium float is not always the right call for a broom finish

I was working a driveway in Tampa last Tuesday, maybe 80 degrees and humid as hell. Wanted a nice broom finish so I figured I'd use my magnesium float to open it up smooth before the broom. Big mistake. That float sealed the surface just enough that when I hit it with the broom, it left these weird drag marks and the aggregate wouldn't push through evenly. Looked like a cat walked across it. Ended up having to run a light rub with a sponge float to blend it all back together before it set too far. Customer was watching from the window the whole time too. Has anyone else run into this issue trying to broom after a mag float?

21

the_rose•13d ago

Hit 500 yards of concrete placed last month and it got me thinking

I checked my logbook and realized I poured my 500th yard on a small driveway job outside Grand Rapids. That number surprised me because I remember when 20 yards felt like a huge project. It made me think about how much I've learned since I started out mixing bags by hand in 2012. How many yards have you guys placed since you got into this trade?

27

tylerr29•13d ago

Old timer on a job in Boise told me to wet the subgrade before pouring and I thought he was crazy

He just said 'son, dry ground sucks the moisture right out your mix and you'll be fighting cracks all week' and I brushed him off until I had to demo a section three days later that looked like a spiderweb, has anyone else had a random old school tip that ended up being completely right?

8

lee.lucas•16d ago

Vent: My driveway apron cracked after 3 winters, neighbor's looked perfect the whole time

I poured my own driveway apron 3 years ago. Same mix I always use, 4 bag mix with fibermesh. By the third winter there were cracks all over the place. My neighbor across the street hired a crew and his looked brand new. I finally walked over and asked what they did different. Turns out they cut control joints at 4 foot intervals, not the 8 foot spacing I did. One simple change and his is still smooth as glass. Has anyone else learned a cleanup trick or finishing tip the hard way like this?

20

oscarcooper•16d ago

Tried a cheap wet saw blade for a driveway job and it was a total waste

Picked up a $25 blade off Amazon for a 600 sq ft driveway in Phoenix and it was dull after 30 feet. Has anyone else found a decent budget blade that actually lasts for thicker pours?

26

noah917•19d ago

Rant: The difference between a broom finish before and after the sun hits it is ridiculous

I saw a neighbor's driveway go from a perfect consistent texture to patchy crap in about 45 minutes because he waited to start finishing until 10 AM and the hot sun flash-dried half of it before he could get his broom on it, has anyone else dealt with timing a broom finish against direct sunlight?

21

rosew37•20d ago

Vent: Used to just eyeball my mix ratios until a slab cracked in half last summer

Now I measure every batch with a bucket and scale after that 6x8 patio split clean down the middle three days after I poured it - anyone else have a failure that made you change your whole process?

10

hugoj86•25d ago

Had a talk with a retired guy at the lumber yard that changed how I mix my mud

This old timer named Earl saw me loading bags of Portland and told me I was wasting money on the expensive stuff when a 50/50 mix with lime and sand gets the same result for half the cost. He pulled out a worn out notebook with numbers from 1987 showing his mix ratios and how they held up for 30 years. I tried it on a small driveway apron last Tuesday and the finish came out smoother than anything I've done with the premix bags. Any of you guys ever mess around with custom blends like that?

27

pat_hall87•26d ago

Just found out my crew has been using the wrong curing compound all year

Checked the spec sheet from a job we did 6 months ago down in Austin and realized our supplier swapped us to a cheaper resin that doesn't meet ASTM C309 standards. Has anyone else's supplier pulled something like this without telling you?

20

uma306•27d ago

Hand troweled a slab in July heat and paid for it

I was finishing a 12x16 patio in Phoenix last summer and the sun hit it just right around 2 PM, turning the surface into a crusty mess before I could get my final passes done. Ended up having to wet it down and rework a 4 foot section that looked like a cracked desert floor. How do you guys keep a slab from setting up too fast when you can't shade it?

5

sethanderson•28d ago

TIL the hard way that hot weather screed timing is no joke

I was pouring a 30x40 slab outside Phoenix in July and thought I knew what I was doing. Got distracted helping the guy with the hose and by the time I got back to the screed, the mud was already setting up on me. Had to bust out the trowel and work like crazy just to get it flat, left a rough finish I'm not proud of. How do you guys time your hot pours when the sun's cooking everything in 20 minutes?

21

faithbaker•28d ago

TIL that a wet spot on a garage floor can ruin a whole day's work if you don't catch it early

I was doing a garage floor in Phoenix last June, about a 500 square foot pour, and everything looked perfect. But about halfway through the finish, I noticed a dark patch near the edge where the slab was still wet. Turns out the ground underneath had a low spot that held water from the night before, and it wicked up through the concrete. I had to stop, wait for it to dry out, and then patch that section after it cured. It left a visible color difference in the final slab, and the homeowner noticed right away. Has anyone else dealt with moisture coming up from below like that?

6

simon_wood72•29d ago

Showerthought: That scorching July week nearly ruined me...

Back in July of 2022 we had a five day stretch where temps hit 102 every afternoon here in Phoenix. I was finishing a driveway for a guy off 32nd Street and the concrete was setting up so fast I couldn't keep a decent edge on it. By the third day I started mixing in a retarder just to buy myself an extra 10 minutes of work time. The worst part was the wind kept picking up around 2 PM and dust kept sticking to the surface before I could get a broom finish down. I had to resoak the whole slab and re-broom it three times on Thursday alone. My foreman actually said "if you don't slow down you're gonna burn yourself out" but I was just trying to get it done. Anyone else ever deal with concrete setting up too fast in extreme heat like that?

18

shah.olivia•1mo ago

3 year old driveway pour still has me defending my approach

Poured a 30-yard driveway near Eugene back in June 2021. Did a light broom finish instead of the heavy swirl the HOA wanted. Foreman called it "too plain" and told me to redo it. Three winters later and that plain finish still has zero cracks or spalling. Their fancy swirl jobs are already flaking. Why is everyone so scared of simple broom finishes?