c/concrete-finishers

9

the_nancy•4d ago

Stamped overlays vs. staining old slabs: Which held up better for you?

I just finished a patio job in Austin where the homeowner wanted me to pick between a stamped overlay and acid staining the existing 20 year old slab. I went with the overlay since the base had some cracks, but now I'm seeing a bit of peeling near the edges after 6 months. Has anyone else had trouble with overlays on older concrete, or is staining the safer bet long term?

23

ivanb41•5d ago

Just compared hand troweling vs power troweling on a 40 yard slab last month

I had a 40 yard garage floor pour over in Baytown and decided to let the new guy run the power trowel while I did a section by hand. The power trowel section looked flat at first but after it cured there were these shallow low spots you could feel with your foot. My hand troweled section came out dead flat and took a denser finish. Has anyone else seen this on bigger residential pads?

33

hayden720•7d ago

Tried a power trowel after years of hand finishing... big difference

I finally rented a power trowel for a slab job in Denver last month, a 36 inch Whiteman. Usually I hand finish everything cause I like the control, but this 5000 square foot warehouse floor was just too much. The power trowel got a way tighter, smoother surface in half the time, and my knees didn't hurt for a week after. Has anyone else switched over for big jobs and not looked back?

14

benbrown•8d ago

Hot take: Broom finish with a push broom beats a textured roller every time

Did a driveway last month over in Salem and forgot my roller at the shop. Grabbed a standard push broom from the truck just to finish it up. The broom gave way more consistent lines and didn't leave those little dots that always bug me. I've been using rollers for 15 years and never thought to try the push broom again. Anyone else ditched the roller and stuck with a regular broom?

20

robin658•9d ago

Why does nobody talk about how air pockets form in stamped concrete?

I was working a driveway job in Medford last Tuesday, everything going smooth with the stamping, then I lifted the mat and saw these dime-sized bubbles all over the surface. Turned out I was vibrating the mix too much and trapping air against the release agent. Anybody else run into this and found a fix that doesn't wreck the finish?

3

luna_sanchez•13d ago

Had to pick between a mag float and a Fresno for my first flatwork job

I was finishing a garage slab in Des Moines last month and kept switching back and forth. Started with the mag float to bring up the cream but then tried the Fresno and it left less chatter marks. Ended up sticking with the Fresno for the final passes because it gave a smoother finish. Anyone else find one easier to use than the other for bigger pours?

25

the_river•13d ago

Remember when we used to finish concrete by hand with wooden floats?

I've been doing concrete work since 1998 and I swear back then we did everything with wooden floats and hand trowels. Now days every young guy on site wants to use those magnesium bull floats and power trowels for everything. Last week I was on a job in Frederick and watched a kid try to use a power trowel on a small patio. He ended up burning the surface and we had to grind it down the next morning. I get that power tools save time on big slabs, but for anything under 500 square feet I still grab my old wooden float. The finish just comes out smoother and I can feel the surface changing under my hand. Anyone else stick with the old ways on smaller residential jobs?

7

chen.phoenix•13d ago

Got chewed out by an inspector on a slab pour last month and it changed my whole approach

I always thought I was fine with my control joint spacing until this county inspector in Austin told me I was asking for random cracking on a 30x40 slab. He said my 12 foot spacing was too wide for that mix design in the Texas heat. Now I keep every joint at 8 feet max and I haven't had a single call back about cracks since. Anybody else run into inspectors who actually saved them from a headache?

17

nancyd85•14d ago

An inspector's comment on a slab last year made me change my approach to curing

I was finishing a driveway in Austin last spring, nothing too fancy, just a standard broom finish. The city inspector came by and pointed out I wasn't wet curing long enough, only doing it for three days instead of the full seven. I always thought it was overkill, but he showed me some test cores from a job that failed from surface cracking. Now I take the extra time to keep the burlap wet for a full week, even on smaller residential jobs. Has anyone else had a strict inspector teach them something useful?

13

hall.quinn•14d ago

TIL a wet burlap drag can save a broom finish from rain damage

After 12 years of panicking and tarping every time a shower hit my fresh broom work, I finally tried a wet burlap drag like an old-timer in Phoenix told me to, and it smoothed out the raindrop pitting in under 10 minutes. Has anyone else used this trick on a big slab, or do you just wait it out?

22

reese_fox•15d ago

Been floating concrete wrong for 5 years until a guy in Fresno called me out

I was using a bull float with the flat side down like a dummy, didn't realize you're supposed to lift the front edge. A finisher with 30 years experience saw me on a job and asked if I was trying to make mud pies.

3

zara_perez62•16d ago

Hot take: Hand troweling a slab in 95 degree heat like my old man taught me is dumb

I tried it last August on a driveway in Phoenix. Mix was setting up before I could even get a good finish on it. The old way he showed me with the long strokes and waiting for the bleed water just turned into a mess. Ended up with a rough surface that took twice as long to grind down. My neighbor who runs a crew out of Mesa told me I should have used a power trowel with a spray bar and some evaporation retardant. I learned the hard way that the old methods don't always work when the concrete is cooking in the sun. Has anyone else had this happen when they tried to follow old timers advice on a hot day?

6

leo603•16d ago

I used to wet cure every single slab for 7 days. Now I barely wet cure at all.

Back when I started in 2005, my old boss would lose his mind if we didn't keep those burlap sacks soaked for a full week. Tarps, sprinklers, the whole setup. Then about 3 years ago I did a big warehouse floor outside of Richmond and the customer wanted it done in 4 days. I said forget it, just used a cure and seal instead. Floor is still fine, no cracks, no dusting. Now I only wet cure if the weather is hot and dry or if the spec calls for it. What do you guys do? Stick with the old way or switch to cure and seal?

5

the_jake•16d ago

Spent 6 months troweling my garage slab wrong before a neighbor called me out

I was out there every weekend for half a year doing my own garage floor, thinking I had the finish down perfect. My neighbor Tom, who did concrete for 30 years in Houston, walked over and asked why I was dragging my trowel like a broom. Turns out I was using way too much pressure and not letting the cream come up natural-like. Has anyone else had that moment where a simple tip from an old-timer made you feel like a complete rookie?

4

kevin_adams•17d ago

Hand troweling vs power trowel on garage floors... no contest

Did a 30x40 garage slab last Tuesday in Columbus and let my helper use the power trowel for the first pass. Walked off for 5 minutes and came back to swirl marks everywhere. Had to hand trowel the whole thing again with my magnesium to fix it. Power trowels are great for big warehouse floors but for residential garages I stick with hand work every time. Anybody else find power trowels cause more problems than they solve on smaller slabs?

2

oliviabennett•20d ago

Just realized that using a hand float on a large warehouse floor in Phoenix was a huge mistake

I spent 8 hours troweling a 10,000 square foot slab in June when the temps hit 110 and the concrete set so fast I had 3 cold joints that took a grinder and 2 days to fix, so has anyone else learned the hard way that a power trowel is worth the rental fee?

9

thompson.finley•21d ago

Had a 4-yard slab crack through the middle after 2 days

Poured a patio last Tuesday and the whole thing split right down the center because I didn't put enough expansion joints in a 40-degree stretch, has anyone else had a control joint fail that fast?

13

holly63•21d ago

Spent three days fighting a slab that just would not cure right

I had a patio pour out in Denver last month that took forever to set up. I thought it was the mix, but turns out I forgot to account for the ground temp dropping at night. Ended up having to tent it with heaters for two extra days. Anyone else ever misjudge weather like that?

12

evah40•21d ago

The day a wet slab nearly cost me $2,000 in Denver

I was finishing a 400 square foot patio in Denver last August and the weather forecast said clear skies. Around 3 PM a surprise thunderstorm rolled in and dumped rain on my fresh pour before I got the tarp down. I had to grind off the top inch and redo the whole surface layer the next day, costing me an extra 12 hours and $200 in materials. Has anyone else dealt with a surprise rain that ruined a finish? What do you do to protect the slab when you can't get a tarp on fast enough?

15

lisa671•22d ago

Just realized most concrete jobs fail because of water, not mix ratio

I was reading through ACI documents last night and found out that over 80% of concrete cracking issues come from too much water on site. Not bad aggregate or weak cement, just guys adding water to make it easier to work. Now I'm wondering, do we really need that high slump or are we just making more work for ourselves down the line? My foreman always says wet concrete is easy concrete, but those repair bills tell a different story. Who here has seen a slab fail years later because someone dumped a hose in the truck? That stat really changed how I look at my water reducer usage.

2

green.jessica•23d ago

Tried Metallic Epoxy vs Regular Stain on a garage floor job

Finally used a water-based metallic epoxy on a 2-car garage last week after years of just acid staining. The depth of color was INSANE compared to what I'm used to. Has anyone else found the prep work way more forgiving with the metallic stuff?

17

richard_ramirez•23d ago

Caught a sneaky concrete cure failure on a 30-yard pour last month

I was double checking some slab specs from a job in Phoenix and stumbled across a stat that said over 60% of concrete cracks show up because of bad curing in the first 48 hours. Never realized how fast those tiny surface checks turn into real problems. Any of you guys ever run a moisture meter on day 3 to catch it early?

4

rowanjenkins•25d ago

Showerthought: learning the 'jitterbug' trick for wet concrete saved my back after 12 years

I was fighting with a sticky mix on a driveway in Portland last summer and an old-timer showed me to tap the float edge lightly instead of dragging it. Cuts my finishing time by almost half on those tricky batches. Anybody else swear by a weird little move like that?

10

beth_mitchell•25d ago

Noticed a huge difference in a slab we did last spring after waiting 3 hours versus pouring right away

We poured a 40x60 slab for a barn near hagerstown and waited for the water to dry up before finishing, and that slab came out smoother than any we've done right after pouring. Has anyone else tried waiting longer before starting the finish work?

28

nelson.gavin•26d ago

Nearly lost a slab when the sun hit a half-finished pour last June

I was working a driveway in Phoenix, about 400 square feet, and the temp shot up to 105 by 10 AM. I had my crew going but we got behind because the rebar was tied wrong from the day before. Right as I started the final pass with the bull float, I noticed the surface was already skinning over and cracking at the edges. I grabbed a spray bottle with evaporation retarder and hit the whole thing fast while yelling at my guys to get the tarp rigged. We got it covered and misted it for two hours straight, but that panic reminded me how fast you can lose control. Has anyone else had a close call with a hot day pour and a slow crew?