How to Repair an Uneven Slab [Best Method] | Concrete Repair DIY

Uneven concrete isn't just unsightly - it can be a dangerous tripping hazard. Let's repair an uneven slab with concrete Expert Dirk Tharpe. He'll walk you through the fastest, most economical way to address uneven slabs using Sakrete's Fast Setting Cement Patcher.
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0:00 - Welcome to Sakrete Pro Tips
0:25 - Repair Options
2:10 - Planning Your Repair
2:47 - Surface Prep
3:09 - Mixing
3:30 - Filling the Crack
4:28 - Building the Slope
5:53 - Broom Finish

[@shane250]

I did exactly that (with the painter's tape and brush) to creat a small ramp between my walkway and driveway. The height difference was about 3\4". It has gone through 3 Canadians winters now. The feathered edge (and the rest of the ramp) still look like the day I finished it. I LOVE this stuff! I just wish there was asphalt repair that would hold as well as this one.

[@SakreteOfficial]

Gotta love a good success story! Asphalt is a tricky one, that's for sure. You looking at a pothole or something more complicated?

[@shane250]

@@SakreteOfficial Naaa, even less complicated. I can't seem to find a crack filler that last more than 1 winter here in Canada. I prep like crazy, and follow the directions to a T (I do it when there's no rain in the forecast for 3 days, and apply it in the very early morning when it's about 65⁰f).

[@SakreteOfficial]

Tough conditions up there for sure. Maybe groove the joint out a little wider and try a cementitious fix? Our friends over at RapidSet introduced an Asphalt Repair Mix somewhat recently - basically a tinted, polymer-modified concrete mix - that might be worth a try.

[@jonoswellii9708]

I haven't used Sakrete in quite a while. Great products and a good couple of videos. I hope to see you all at World of Concrete this year.

[@SakreteOfficial]

Appreciated! Can't wait for WOC - we'll see you there!

[@user-by8yq3vn5j]

I followed you here (thanks!) and this is what I've been looking for since March '23. Sidewalk isn't cracked, a root pushes the slap from about 2" high down to an even point. I'll use Top N Bond but I'm confused about the "SSD". Painters' tape is pretty common to see around here, so I'm convinced it'll work. But then do I need to use another product? I get that the cement needs to adhere to the sidewalk. I can handle hydraulic cement but this is new for me.

[@SakreteOfficial]

Right on! This should work perfectly for you. "SSD" is simple - just getting the surface wet before you apply the patch. The simplest form of surface conditioning, as opposed to using a primer. The acronym is "saturated surface dry" and basically means that the concrete is at a neutral moisture content that neither adds moisture to the mix nor pulls moisture out of the mix. You know you're at SSD when the concrete LOOKS wet, but is dry to the touch.

[@claudettetooley]

I wish the camera was positioned over the work area so we could actually see what’s being done.

[@SakreteOfficial]

Good note - we'll consider that for the next one!

[@msbrownbeast]

Should you allow some time for the filled-in crack to harden and dry before putting on the top coat? Also according to the Top'n Bond instructions, it's not supposed to be more than 1/2" in thickness on each application, and it seems it is more like 1" thick at the high end in your demo. In that case, should there be 2 separate applications?

[@SakreteOfficial]

Give that first layer a couple of minutes to reach an initial set, but you don't need to wait for long. The application depth is probably a LITTLE high in this example, but Top 'N Bond still did a nice job. By the book, it would probably be best to do this pour in two lifts.

[@Bamaoutdoors]

Thanks for sharing! Can I drill this after it sets up? I have to fix some spots on the edge of my barn slab that will be just like you did here but I have to put anchors through it to hold down the wall that will sit on top of it.

[@SakreteOfficial]

Absolutely - just give it the full 28-day cure time before you go drilling into it. Thanks for watching!

[@sandywjo5]

I can't find any videos that show what color this top bond dries, any followup videos on the finished product?

[@SakreteOfficial]

Top 'N Bond is a pretty natural concrete gray. Probably a touch darker than the concrete you're repairing, but not glaringly obvious like some other repair materials. Good note though - we'll look into updating this project guide!

[@JP-pf1nj]

What's recommended for resurfacing a 13x12 patio with a bunch of cracks and pitched the wrong way.... thinking of skim coat 1-2 inches

[@SakreteOfficial]

Sounds like you're looking at a cap - we've got a video on that one! Check this out: kzbin.info/www/bejne/q6Cxd2ODlsyFqac

[@cameliaodeyemi]

I have a uneven surface and a crack would I repair the crack first and then cap the slab or what would you recommend?

[@SakreteOfficial]

If you're going to cap the slab, you can certainly take care of that crack repair at the same time!

[@beauwitka3926]

I just bought some Top N Bond to use to skim coat my basement walls to fill surface imperfections left by an incompetent contractor. There are two things that the bag of Top N Bond instructs me to do but I don't see on this video: 1.) priming the surface with a slurry of Top N Bond. 2.) keeping the surface moist while it cures for 24 hours. I would prefer to not have to include these steps. Are they necessary?

[@SakreteOfficial]

Let's break it down: 1. The priming is helpful for increasing bond strength. New concrete doesn't like to bond to old concrete, believe it or not...so by giving the new skim coat some "fresh" concrete to grab on to, you're going to guarantee that it locks in place. 2. Curing is the most critical piece of any concrete job - lose moisture too fast and you can see shrinkage cracks. Wet curing is the easiest way to ensure the cement has all of the water it needs to complete its chemical reaction at the right speed, so you get a picture-perfect finish. To be fair, not MANDATORY, but definitely highly recommended!

[@jonoswellii9708]

Update Folks me and the Wifey have our tickets/hotel/flight. We will be seeing you there ready to glean some more information!!!!

[@SakreteOfficial]

Right on! We're right in the middle of South Hall - S10826!

[@truthalonetriumphs6572]

The music! Lol ... did we invade a country or something? It's a concrete patch for God's sake.

[@SakreteOfficial]

Are we the only ones who get THIS excited about concrete? 🔥🔥🔥 🤘🤘🤘

[@brendonjohnson6595]

I was thinking the same thing!

[@krissylong6992]

This is no laughing matter. It’s a trip hazard for gods sake!

[@robinlee7485]

Can I grind down a 4'x8' section of concrete that rises to an 1.5" at its high point?

[@SakreteOfficial]

Meaning the height difference is 1.5" from the low end to the high end? Suppose so...but that's going to be a LOT of grinding, and potentially leave you with some really thin areas. Probably better to patch / overlay. You might have a heaving situation down there!

[@golfshoe9321]

@@SakreteOfficial My drop is about 2", should I put down one layer, dry, and then apply another layer the next day?

[@SakreteOfficial]

@@golfshoe9321 Bingo - that's the exact process! You could also look at using a mix like Pro-Mix All-Purpose Cement that would allow you to do that entire pour in a single lift. If your local Lowe's carries Sakrete, they'll have it!

[@joannemahoney6846]

​@@golfshoe9321I'm curious if you did it? And how it turned out? I have a 2inch drop and my slabs are about 10ft long. Concrete leveling companies want 5,000$ to lift it. I might try this

[@IncognitoLounge2009]

I wish there was a link to buy

[@SakreteOfficial]

Head on over to Sakrete.com/Where-To-Buy - as close to "click to buy" as you can get!

[@xingchang99]

For the cheap method, how long does it last?

[@SakreteOfficial]

That's the issue - almost impossible to say in advance! It all has to do with how "active" the movement is. Like Dirk said in the video, this patch might last years (if there's not much movement) or just a few months (if it's still very active). The only guarantee for longevity is tearing it up and re-pouring...but a good repair is definitely the place to start!

[@anthonynotarino1996]

Can you use the Re-Cap over this so it blends with the rest of the area ?

[@SakreteOfficial]

You definitely can, though we'd suggest Flo-Coat...Re-Cap is made by the other guy.

[@desmetde]

when you pull the painters tape away , you will leave a huge lip.....dont use the tape!!

[@SakreteOfficial]

Not a bad piece of advice! It's a good marker to help you eyeball the finish line, but killing the tape can't hurt!

[@MikeSmith-em7tc]

To fix the lip can you lightly sponge the lip down to feather it?

[@SakreteOfficial]

Good recommendation there.

[@mrbigcat9]

What do you mean by prime coat?

[@SakreteOfficial]

Good question! We're just referring to using a separate liquid bonding agent (or primer) to ensure bond strength. Because Top 'N Bond is a polymerized mix, you actually will ONLY want to prime using water to bring the slab to SSD. Other mixes (like Fast Setting Cement Patcher) would benefit from using a liquid primer like Bonder & Fortifier.

[@marian7440]

If our 1978 concrete patio has cracks and random (up to 2” wide / 1/2” deep) rough chipped divets, would you recommend having the patio sand-blasted or commercial rotary sander to remove 12 years of heavily weathered (Seattle rain) concrete paint, then repair surface chips and cracks with this Sakrete primer? Once surface is repaired what decorative restorative treatment would you recommend in our moist Pacific NW climate? Thank you!

[@sparkh.9345]

Yeah but what's it look like when its dry? All sakrete videos never show that!

[@SakreteOfficial]

Looks like concrete, baby! Seriously though, patches are generally slightly darker than existing concrete, but will lighten as they age. Also a good point - we'll make a note to show the final cured product in the future!

[@yourandrewjohnson]

What's a form? (5:08)

[@SakreteOfficial]

A form is essentially a frame or "mold" that you would build around the repair area to hold material in place. Dirk is demonstrating how to "freehand" this repair, which is pretty advanced stuff - using a form would make it a heck of a lot simpler for non-experts.

[@ms.yuppio5380]

To add a scenario, if you get your foundation repaired and go to replace your flooring you pay find situations like this....

[@SakreteOfficial]

All sorts of stuff hiding underneath flooring...good to have some tools to combat those little (or big!) imperfections that always seem to pop up!

[@jeremygordon4483]

You have to raise the lower portion from underneath. Next video.

[@SakreteOfficial]

Yep, correcting the underlying issue is definitely the RIGHT way to do it, but sometimes the repair is all you've got time (or budget) for. Options!

[@dus10dnd]

You forgot lifting the slab. It relatively easy.

[@SakreteOfficial]

Via foam injection?

[@dus10dnd]

@@SakreteOfficial perhaps, or other means.

[@SakreteOfficial]

Tried the other method. Hurt our back.