The Right Way To Seal Expansion and Control Joints

This looks like WAY too much work. Have you tried Trim-A-Slab for expansion joints? It takes about as long to put in as the backer rod, doesn't need the cleaning step, it can make a ramp between the slabs, and you would be done in a fraction of the time. This is a well-made video, great presentation, but this method is kinda last-century.

Thank you for all the info!

I used spray foam for the filler and backer rod. Worked like a charm. Just came back later and cut the excess down before applying the sealant.

If you have the proper sub base of rock allowing proper drainage, this isn't an issue.

Cool 😎 !

Contraction joints should only be filled during colder months just above freezing. In doing so the sealant applied will be under compression during most of the year.

Awesome video. Questions:

1) any reason to use polymeric sand, which allegedly hardens when wet?

2) would Sika 1A on the sides help to seal micro cracks before applying the self leveling sealant?

3) any reason to use acrylic concrete sealer on top of the final layer of sand to water proof it?

Thanks for the fantastic content!

What if the joint is running with the slope? Perpendicular to your example. Go with semi self-leveling?

Why would they be skeptical of using a pool noodle? They're more or less the same thing.

Great video. For those of us that have wood slats between the expansion joints, would you recommend a different approach where the wood somehow stays, or just fully replace the wood with a wider strip of sealant?

Looks good but I would have added more sealant to left the backer higher so that the sealant more closely matched the driveway level.

Why?? STOP…just stop. Your solution does NOT MAKE SENSE. You NEVER address ALL THE GAPS below the surface (backer rod??) You are just creating/filling a surface solution. What if water goes underneath the backer rod (it will). Your duct tape on the side perfectly illustrates that issue.
Here is what worked for me.
Clean/vacuum the crack. Use a screwdriver, pressure washer, vacuum with crevice tool. Remove as much dirt/sand as possible.
Buy the Window foam sealant Great Stuff with the Foam Dispensing Gun ($50). The gun plus the smaller black tip works great when shoved deep in the crevice. The foam goes in every nook and open void. It will adhere to the sand/soil/tarmac/cement and create a monolithic structure. There will be zero spots water, ants or critters to go.
Any overage…just trim with a utility knife.
Have a great day.
You cannot have frost heaves or critters if water is not available/present.

Thank you Scott!

Your video was generally good. The problem with your product recommendations of the Sika or Vulkem products will work is longevity.They will usually work for 5-10 years depending on heat and sunlight the joint is exposed to. If you want to do this project only once, use Dow Corning's Dow 890 (self leveling) or Dow 860 (vertical grade) silicone sealant. These products will last 20-30 years and are the only sealants specified for highways in Califorinia's Department of Transportaition. I was a waterproofing and sealant distributor in California for over 30 years. We sold all the products your mentioned in addition to the Dow sealants. Yes you will pay 20 to 30 percent more for the silicone sealant but in the long run it is well worth it.

Our neighbor had bamboo. The bamboo is gone now (my husband talked him into letting us cut it all down), but of course the rhizomes still sprout. My concern was that bamboo would get under our driveway and try to come up through the cracks. We put in a rhizome shield but still I am wondering if we should replace our backer rods to discourage rhizomes.

Its fine, there's no reason to seal it. 80+ year old pads like this with zero issues.

I've watched several of your earlier videos on the expansion joint repair and recently replaced the joints in my front walk. The results were great! The prep was the hardest part but not too bad except I had to get a better pair of knee pads. My only mistake or room for improvement was to make sure the play sand I used was completely dry. For my first joint, it was still damp and went down in clumps and made the finished surface irregular. However it still looks great. Thanks for the instructions and tips.

May I ask why you did not bring the product up higher on the expansion joint. Thanks.

I welcome our a Finnish brothers,?it’s a big step to join us…. I pray we be worthy.

Consider using a silicone product instead such as DOWSIL Contractors Concrete Sealant for something that lasts.

The Fire ants are crying after this video. They love making nests in those cracks

NICE JOB!

We have to grind the raised edges on driveways and sidewalks in my Condo community since ADA only allows a 1/4" maximum edge difference . We've had some of our older residents trip on 1/8" because they shuffle their feet. Potential lawsuits waiting to happen.

You have an excellent channel. Just watched a voltage tester video and I REALLY approach your approach and humility. Excellent channel with excellent explanations.

A lot of DIYer’s don’t understand what sand and backer rod actually do when trying to fill a void with flexible sealants. Sand decreases the depth, backer rod stops the flow of sealant and provides a surface that the sealant won’t adhere to. Flexible sealants perform best and last longer when they only adhere to two apposing surfaces. Imagine stretching a rubber band between 2 fingers, it’s stretchy with minimal tension. (Sealant adhered to both sides of a crack applied on top of backer rod) Now fold the rubber band over a couple of times and try to stretch it. It becomes rigid and stiff. The latter would demonstrate filling a void without using sand and backer rod. In this case, as the 2 pads of concrete expand and contract, the sealant wouldn’t have enough flexibility to stay attached. Hope this helps

how many ants were killed or maimed during this?

Need your advice: one corner of one concrete slab in my driveway raised above the next one from 1/4 to 1/2 inch and a crack opened (1/8 to 1/2 inch wide) extending 6 to 8 feet along two sides of the slab. Last year I did a cursory sealing with caulk but the settling continued and the seal is broken all along the crack.

My question is: what’s the best way to remove the failed caulking so I can redo the fix correctly?

Hey bro, there is a tar product out now made for blacktop driveways that you use a torch to melt it, and a putty knife to press it in. I'm thinking that might work here too, since adhesion is the biggest obstacle to overcome. Adhesion would be heat based, and might withstand the rigors of winter better. Any thoughts?

Well done 👍

BTW, I can attest to your pool noodle solution, that it does work and work beautifully. I used it in a large crack that was too wide for backer rod, and I filled it with Sika. Still holding up after a year so far of very harsh weather and temps.

Great video

I don't understand the difference between Sikaflex Horizontal Joint Selant and Sikaflex Crack Flex Sealant. Home Depot sells both. The prices are $8.92 vs. $9.92 for 10.1 oz. tubes.

Ive never seen self leveling last very long. All i know is when i go fix a homeowners "diy" with self leveling its a horrible mess. I dont recommend doing this yourself. It just makes my job harder and costs the customer alot more money.

It’s not a bad idea to seal these joints, but it’s not going to make the concrete last “2X-3X” unless it was prepped incorrectly to begin with.

This one was easier than some past ones, but I'm surprised that you didn't fill it higher. Maybe a second layer of backer rod, then fill. That depth will fill with debris and grow weeds and grass more than a thinner depth. Would filling almost level for less of a debris trap be a bad idea? What's your stopping point in general?

Thanks for the pragmatic tips, very helpful. Not everyone has the money to just redo a driveway. I'd rather get 5 years out of a pool noodle in a gnarly crack and spend the big money on something better.

I’ve got some type of plastic/composite strips (approx. 1 in w) in my concrete joints. Guessing they’re also 3-4 in tall/deep into the joint as well. The ends have lifted in a couple of spots and I’ve no luck getting them to stay back down flush. In the winter my snowblower gets stopped dead on these spots. What are they actually and how do I repair or replace them?

Great timing, my project for this week! You've removed a lot of stress for me. :)

I Sika'd my driveway last week, and it worked great. Real solid hold on the concrete. I gave up on the backer rods because my gaps were wild, so I just compressed damp play sand to fill up to about 3/4" from the top of the crack after power washing the day before (instead of nylon brushing the day of). I didn't have any issues, aside from your observation of using a lot more than advertised. One huge tip I have for Sika explicitly is that the product is INSANELY forgiving - do not worry about making everything perfect, as you have plenty of time to backfill after you finish an entire run.

Thank you for this video; I just finished doing this to my sidewalks but I used sand to fill the cracks then the self-leveling caulk; no backer rods. Will I have issues in the future?

Very interesting. Thanks 👍

Thank you for the great instructions and the products you have used successfully! For larger gaps could you use foam pipe insulation if pool noodles aren’t available?

Hmm. This is a common topic on this and other channels. And I think you yourself have a similar video--filling, not sealing--on this very channel.

But let me say, Scott, this was THE BEST "ground-laying" intro I've seen.

Keep it up; you're crushing it!! :)

Instead of backer rods, could you use a can of Great Stuff?

Interesting

i use sika adhesives all the time, as i work in a glass/autoglass shop. tried piles of other types, but sika products are reliably good.

I did this on my driveway already and I'm pretty sure I followed a video that you already made...?