How to Fill in Cracks in Concrete 

I had similar cracks in the sidewalk. I filled them in with epoxy mixed with sand and then applied a thin layer of concrete to level out the square of broken and unlevel sidewalk. Looks like a new pour and still looks good with no cracks after 2 years.

I have made these repairs professionally for over 40 years. Well done. I have only a few suggestions/comments. 1. The backer rod provides proper depth control and proper profile to the bottom of the sealant. So technically the backer rod needs to fit snuggly. ( this is only a technicality and many professionals will do what you did it will affect sealant performance but in this instance I doubt it will be significant) I understand you do not have a wide selection of backer rod. 2.Since you took the time to get the correct backer and prepped the cracks correctly I would have not used a consumer product but would have used a professional quality sealant made for just such applications like Vulkem45SSL . And I would have primed the joint bonding surfaces.Also while tooling the joint is not mandatory it forces the sealant into contact with the bonding surface. These are the only differences between what you did and a high quality professional installation. These are all pretty nit picky issues. Very well done. After seeing the results after one year it is kinda what I should expected from a consumer product.

Someone mentioned using play sand instead of backer rod. You can also dump play sand on the final layer of filler, let it dry 12 hours, brush away the excess and the final finish looks more like concrete than the dried filler.

Thank you for the product review and the one year follow up! It’s really great to have the knowledge of different products and be able to make comparisons and decisions of what to use !

That stuff is very good. I sealed a crack 3-4 years ago, maybe longer, and it's still holding very nicely.

Cheers mate. Been wanting to know the best way to repair a large crack in my patio. Very hot summers here in Australia. Keep up the good work.

We do this exact method at work,but we also use a primer from BASF that has sulfur in it that etches into the concrete the sealant will never pull up or pull away from either side of the crack when concrete shifts again after winter it’s an amazing product any brickyard carries it👍👍👍

Great video brother, thanks for sharing hopefully it's still holding up well? Can't wait for the 1 year review

I’ve tried them all. slab concrete filler in a tube worked best for me. Going on three years without any issues 👍

Thank you for the demonstration!

I would recommend sprinkling some of the dust from the concrete over the repaired cracks to blend it in.

You're a good thorough worker. I like that!

thanks for the email regarding filling in the cracks in cement1!! great...very explicit!

Have watched multiple crack repair videos; yours is what I am going to use. I am mediocre handy, can’t squat and have an unusual way of trying to get up once I sit or get down: it will probably be a 5 fbomb I for me: multiple cracks need filling: Thanks for this video!

I really enjoyed this video because doing my drive way I spent about 100$ and now the crack is up higher the cement moved if I would of known about that filler it would of saved me probably busting up the whole slab of the drive way which is a easy grand dang thank you

Interesting stuff! Hopefully this saves me a contractor visit!!

Just what I need.have to try this.thank you.

Thanks very good even could follow your instructions 👍

I have a poured patio 12' along side of a concrete walk, and the gap is around 3/4". There was tar type material concrete guy put in but it desintergrated. I'm thinking to use a gray type flexible goo. Any ideas what I should do first and and then afterwards? Thank you

I used my leaf blower and forced the cement down further and so I would not need to come back the next day to refill the cracks, That cement crack filler works very well. The bottle is too fat for my hands so I used the red plastic ketchen container and kept filling it up. The ketchup bottle has the prefect neck to it Did not need to redo very much the next day. Three years later I needed to fill a few areas. after I blew the debri away with the blower. It took me a few minutes to get the leaf blower the prefect speed I needed to force the crack filler in. But using the blower also gets you standing again just in time. I also used the car roller to ease around and put my stuff on the shelf of car roller. And then you can use the blower if it gets hot. Three ways to use that one tool. Every crack you get on a slab can be traced back to water is causing it. So I find that problem so no more cracks. Maintaince 101 thanks for the video

Yo. Great info. And i appreciate the PPE. Way to go, brother

Great step by step video; best one I’ve seen

great video and ideas I have some large cracks in my concrete that I need fixing - interesting how you fill the larger ones

I'm filling cracks in my basement this morning before the new carpet goes down but the liquid filler that I'm using is coming out thick like clay. It was working just fine prior, coming out as pure liquid for the first 2 minutes of use. I tried warming it up which did help it flow better with less viscosity for a very limited time. I tried googling "Crack filler coming out like clay" and other similar search terms but not a single article came up in relation to that.

Very good product. I've found that Old string, shoe laces and rope is a good backer alternative

I used the same filler that you used and after a year it cracked, I found out that I was supposed to use a flexible filler you can also put some sand or powered concrete on it to hide the filler but you have to put the powered concrete on when the filler is still tacky , it will not completely hide it but it will not look so bad

I like the Sika branded fillers, they have 1 and 2 part systems that go in a caulk gun; they hold up better, are thicker, and install in 1 day. The 2 part system sets within an hour and is similar to epoxy; it is the strongest sealer and stays flexible enough to not crack/split out but is more expensive than 1 part solutions.

GREAT VIDEOS. VERY COOL. THANK YOU!

Are you kidding? I had a guy give me an estimate which included ripping out the existing driveway and lay out a new cement. Thanks so much 👏🏾👏🏾. I’m taking your method and I’ll repaint the driveway a dark gray with glitter sand on top.

Found ur video interesting n informative . Will try ur techniques to fill the cracks on my driveway. New subscriber because of this video. Kudos for vid. Anticipating ur next one.

Thank you very much for sharing ❤

Great video. Very very helpful

Just what I needed to know. It's another summer project this year. Downloaded. Thanks.

Easy enough. Thank you!

I've always used a runny mortar mix to fix cracks. If there's lots of expansion, it keeps cracking out. I have used a diamond saw and cut 1" wide slots where cracks are. The bond is much better than a thin spot. If it looks ugly, I use a resurfacing vinyl added topping mix. The city refuses to repair walks where I live. It actually has to be a hole before they'll do anything.

Thanks again!!

good to see you wearing knee pads, alot of concrete people dont bother but after i used them once i havent looked back, ACC would like it too,thats new zealands, accident compenstion corporation

Great thanks for the tip.

Thanks Flip!

I believe the sand method is still probably the best method for filling in some of the cracks up to a point. But Home Depot and Lowe's call it caulk Saver in the weatherstripping section. Only commercial companies call it backer rod and can be purchased up to 1 in in diameter for large openings. Great for when you are doing window and door replacements and have large openings to fill instead of that gooey foam stuff!

Ran to Amazon...being delivered next week...thanks

Well done

Put a layer of fine sand under the backer first, in areas where the rod wont quite fill, and smaller sections where it wont fit.

Great video Thank you so much

Good job well done

Thanks for the lesson I'm going to try this around my swimming pool which has a few cracks.

If you fill in the bottom with sand it will seal better than backer rod. Then sprinkle silica sand on top while sealant is wet will produce a better match to concrete.

I've used sand that I pound into the cracks so that it leaves about a quarter inch for the filler. I like it better because it provides a flatter slot for the filler which IMO makes it easier to fill to the level of the concrete. I've had better long term results with the sand as well. The filler is amazingly long lasting but uneven filling can lead to premature failure if it gets too thin.

I have used this very same product from Lowe's. Instead of the backer rod I used play sand, it's much cheaper. pour it into the crack up to about 3/16 of an inch below the surface. Use a chip brush or cheap paint brush to sweep away any excess. The sand fills the crack better, reducing reapplication. Also I have found no need to 'chase' the cracks.

Use a moist sponge to level it out. It looks so much better.

For backer rod to do its job it needs to be wider than the crack it is going in. To stop the liquid crack filler from just flowing past the backer rod it needs to fit tightly in the crack. For a .50 inch wide crack you need to use .75 inch wide backer rod. Most crack repair jobs require several sizes of backer rod. Backer rod is cheap so have several sizes on hand. For a project idea, how about resurfacing that area.

REMEMBER U MUST HAVE A CLEAN CRACK....LOL i was cracking up bro :-)

very nice thank you

Can I use this method to fix leaks bubbling up in many spots in seams in what is now a concrete floor where there used to be only dirt - looks not important, just dryness - in a utility room during heavy rains or when ground is saturated. I had about 5' of additional height space dug out where only 4' already existed. Space was dug out beneath an annex room which was attached to the the main house. Annex room sat on footers with just dirt underneath while main house foundation sunk the additional 5' below the annex room foundation on one side of annex room. After floor was dug out, contractor put in concrete floor which connected with roughly bordered block and concrete foundation of main house; plus, the new concrete walls placed under old footers that already existed on three sides of annex room. There are no large visible cracks anywhere in floor. There is a thin "joint"/seam - maybe more aptly described as overlay where new concrete floor meets concrete of old foundation which I remember as being uneven/not straight. There are many spots when it rains hard/ground saturated, that I can see water rising up through this very small seam. Where the concrete floor meets the newly poured concrete of the new foundation, there appears to be no leakage. The seam I am talking about is tiny (and straight) compared to what you show in this video Also, any suggestions for the brick/mortar work in same room. In what is the old brick and mortar on three sides of annex room - below ground level - but on top of original block forming crawl space before dug out to form new room, I can see "streams" of water coming through what must be holes in old mortar during heavy rains. Any suggestions as to how to repair this Excellent video. Thanks for help.

Always keep a clean crack...🤣🤣🤣...I'm here all week, Thank You

You could use an angle grinder with diamond disc. A disc costs about ten bucks. It saves a lot of time and produces consistent results. The more perpendicular the cut is to the surface the less likely it is that the repair will fail.

Do you think I could get a way with just using all purpose Bondo on the cracks? I am just looking to fill some cracks in my drive way for the purpose of skateboarding during the quarantine. I know it wont look pretty, but I don't really have the resources to chase the smaller cracks.

Are you able to paint over without noticing the filler? :) wanting to fix some cracks around my pool and paint with a cool sealer.

Nice video with good content and comments. Appreciate the one year follow up. I do have a question … you mention winter … where are you generally … how severe is your winter? Are you UP of Michigan, WV or northern Mississippi. That will help tell the tale on the product, Thank you!

I did the same thing using the same Quickcreate product and while it may fill the crack, it makes it look as ugly if not uglier than when there was just a crack. Next time around I'll fill it with a pool adhesive to help hold from the slabs pulling apart further, plate sanding the top of the concrete so it's nice and flat and putting a top layer of new concrete. Note that I'm not a concrete guy and don't know if this will work or how long it'll last but something has to be better than the quikrete product that doesn't hide the cracks at all.

Thanks

I have used this crack seal and I hate that stuff. I hate the look of it. It is messy, looks awful, then gets very flaky. But I have to ask, why you filled in your expansion joints?

Found your year later video and will watch now 👍

I don’t have concrete in my yard but great video! Thanks!!

it looks just like mine it looks like crap, I tried using a darker dry concrete just sprinkle it on while the patch is still fluid, and kind of pat it to get it mixed in a little but be careful you just want to coat it so it will not be as light

Could you take some of the dust particles left after cleaning and top the crackfiller with it ?

Can this treatment be stained or painted? I have foundation cracks inside the home and am considering painting the concrete. Thank you.

What do you do if the sides of the cracks are uneven? If one side is higher than the other? Do you need some kind of mold around the crack before you apply the filler?

Than you

Real professional 👌 thx

Can u explain how to fix cracked bricks at base of the house where it meets floor

I used to chase cracks when I was younger.

Can I repatch this with same patch material. Mine cracked again.

I reckon the job should have been a concrete lift and replacement. Fix the under laying issue before the new concrete layup. Judging by the cracks there was soil expansion under the the center of the slab. Possibly a broken pipe or tree root. Good vid though on cheap sealing technique.

Bruh we need an update! Does this work better than the two part components that are really expensive? I have a big gazebo that has similar cracks to yours

This is a very helpful video - thank you.

I have doubts about using a vacuum cleaner to get dust out of the cracks. The very fine dust could get through the filters and damage the mechanism of the machine. My technique was always to blast dust and dirt out of the cracks with water.

Interesting demonstration. A simple and cheap way of filling cracks in concrete is to clean them out and then fill them with a cement rich mortar. I use 1:1 cement and building sand. You can get mortar into finer cracks by making part of the mix more watery so it absorbs in better.

What do you suggest to use to fill in black top cracks in driveways ? Thank you in advance

Now I am at DOHS, Mohakhali, Dhaka-1206. How can I achieve this chemical & instrument. Whats will be its price. Please inform me. Thanks

This will work for sidewalk but not a driveway. A 2,000 lb car will just keep cracking it. Use Flex Seal rubber paint after cleaning out the cracks. Moves with the concrete.

I had great results with epoxy resin but I never see anyone else do it

How do you cosmetically fix the concrete AFTER it has been repaired? I have a white line of filler and it still looks awful. Help!

Would it not make sense to pulverize the concrete you chiseled out and then sprinkled that powdered concrete onto the last application of sealant so that the repair appeared more like the concrete?

Hi, I understand what you are doing. Please could you explain what backer rod actually is? I’m in Europe. thank you

My mom use a butter knife and put some cement sealer in the cracks and then a couple of days she painted it

Nice work!! 🩷

When it’s dried, is the material somewhat flexible and rubbery so it can expand and contract?

What would happen if you didn't use use the chisel on the small small cracks and filled them with sealant anyway?

Can you use an angle grinder with a concrete wheel? Thanks!

Bondo works fine. Just do the same prep work no cord needed

Can you use a pressure washer to clean out the cracks? Thank you

Wouldn’t it be a good idea to save the dust from removing concrete so you could sprinkle it on the still wet liquid sealant? That would make the cracks look more like the surrounding cement.

You applied the stuff times two, I didn’t see the name, please forward information.. I could really use that.. THANKS!.. the application you used last.. you stated you had to redo in the morning..

can anyone share the links of '"one year later review" ?? thank you!!

Thanks! Now I can use it to fill my cracked CEMENT LEAF FOUNTAIN!

You can use fine sand to fill cracks first. Much cheaper.

You get a like just for the clean crack statement. Haha.

Does it have to be dry or can this be applied after rain?

I bought some of that product and it was a lot ticker and didn't flow nearly as easy as yours did. Plus it had large blobs in it that wouldn't even come out of the nozzle. Very frustrating.