6:15 -- Sikaflex has been the go-to sealant for years for this sort of project but I find it to have poor long-term performance. It separates from concrete after only five years in pleasant Southern California weather conditions. Five years of protection for so little effort is fine but it's marketed and priced like it will last much longer than that.
If you install Sika correctly it can last 20+ years. If it is only lasting 5 years it is almost always due to improper installation. 3 things usually cause it to pull free from the sides. 1 not prepping the bonding surface correctly. 2 not using backer rod 3 installing it too thick.
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
Sand is better than nothing but it will shorten the sealants life as opposed to backer rod. Backer rod gives the sealant the proper profile to work. Thicker at the bonding surfaces and thinner in the middle so it can stretch. And you are right most people don’t understand how important the proper backing is.
@@paulsosa1872 just a plain bad idea. Guys like that don’t have clue what backer rod does. It not only provides depth control but also the proper profile for sealant. THE ONLY ACCEPTABLE FILLER UNDER SEALANT IS BACKER ROD. PERIOD I have been a professional caulker for over 45 years.There is a reason for backer rod
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.
Totally ignorant solution. With a slab you are dealing with the water sheeting into the joint BECAUSE of the slab. By your logic what stops the water from getting under the slab every single inch of the length of the slab. It is clear you don’t understand what you are doing. I have been a caulking/ waterproofing professional for over 45 years. Your solution is just plain ignorant
Best "how to" on this subject I've seen so far...and I have watched at least ten this year. First time I actually think I can tackle this repair myself, as a first time home owner and DIYer. Great job!!!
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?
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.
@@thejflores1219 The edges are still clinging hard to the surrounding concrete, not even a sign of letting up. My wife had our driveway pressure washed, and it hasn't affected the sealant at all, either.
@@jong2359 After a few years, it will pull away and loosen up. The backer rod is designed to create a uniformed casing for the sealant to wrap around. It does more than just fill the gap.
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?
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.
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.
Is this a good method in order to prevent grass and weeds from growing in between? And is this method also good to seal control joints in the basement to prevent bugs?
Great videos. My local handyman doesn't recommend the self-leveling chalk as you do, saying they don't last long. Her recommends Loctite PL non-sag poly sealant, having used it before. Thoughts?
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.
Still trying to figure out what the little mouse sized thing was on the left of the screen that shot down the driveway at 100 mph at the :43 second mark of the video
Very helpful. For extra credit might I suggest spraying the crack with weed spray and ant/bug spray in your prep step. I found it made a significant difference in the crack maintenance.
DOWSIL contractors concrete sealant is far too soft to use in traffic situations. And doesn’t hold up well to abrasion or punctures. Plus it’s not self leveling or semi self leveling. Most homeowners have a problem with tooling. Polyurethane can last 20+ years if it is installed correctly. Both Sika and Vulkem are far better for this situation.
@@genecarden780I'd like to use the SIKA, but looking at their site I'm not sure which to buy. Can you respond with the product name? Sikaflex -1c SL is what I think would work.
For sure, I have several videos over the years on similar projects. Just trying to roll up the lessons learned and comments from the last videos into an update one . 👍
If the water flows under the slab it will remove the base then the concrete will not be supported and will crack. This happens most on slopes but just takes a lot longer on flats.
I would not. You need a an excellent bond between the sealant to the edges of the concrete, so the top of the edges have to be thoroughly clean . If even a little of that foam gets on there (and it will ) even if you wipe it down before it cures it will leave a film on the concrete that is almost impossible to clean off (ever get it on your hands?). That film will prevent that bond from happening and your expensive Sika-filled joint will start life with a hairline crack that water will immediately start to penetrate. Also, the main purpose of a backer rod is not to just use less sealant, it provides a critical bond breaker at the bottom of the sealant so the urethane sealant can stretch freely with the lateral movement of the slab sections. The smooth surface of a backer rod accomplishes that.
No the only thing acceptable as filler under sealant is backer rod. Nothing else will give the sealant the proper profile to last long term. The rounded shape of the rod makes the sealant thicker at the bonding surface and thinner in the middle so it can stretch correctly.
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.
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?
Just cut the excess off with a saw, for example an oscillating tool or a flush-cut saw. Then you can use a filler to seal it in. I prefer a polyurethane-based joint filler. A self leveling filler makes a smooth finish.
You have an excellent channel. Just watched a voltage tester video and I REALLY approach your approach and humility. Excellent channel with excellent explanations.
My driveway is a continuous pour. I just had it done as the original driveway was damaged by a propane truck. It was originally poured in sections. My sidewalk was laid down in sections with sand in between each section. Only sand. It doesn't freeze here so I assume that's why. I don't know. It's never been a problem since new in 1986. Is this normal for warm locations that don't freeze?
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.
Make a cheap wood or plywood backer rod insertion tool. One bigger disc and two smaller discs, cut from scrap with hole saws. the width of the bigger disc will depend somewhat on the joint width. The difference in diameter between the smaller discs and the larger disc will depend on how deep you want the backer rod set. Use a bolt or whatever as an axle. Figure out a handle. Albion makes a nice one and it's adjustable, but if you don't want to spend $50 plus, just make one out of scrap for free in 10 minutes or so.
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.
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?
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!
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.
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.
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?
The arched surface of the backer rod creates a thinner section in the centre of the caulk bead, allowing it to flex there instead of pulling away from the crack edge.
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?
On my driveway control joints, the crack is about an eight of an inch throughout the joint. Can i just apply a sealer and wait for the crack to get bigger? My house is about 4 years old
I would still put backer rod in the crack prior to the sealant to ensure I can a consistent level for the sealant. Make sure you leave the sealant a bit lower than the concrete so you don't get tire tracks on the sealant when it warms up on a hot day.
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.
From what I can tell there is very little difference between the Self-Leveling and the Crack Flex. If you want the larger 29 oz tube it only comes in Self-Leveling and maybe the Crack Flex blends a bit more without the sand on top 🤷♂️ retail.usa.sika.com/en/products/sealants/non-sag/sikaflexr-construction-sealant
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?
If you have a blacktop driveway yes...concrete driveway I don't think I'd care to put tar on it LOL. I've seen that product you are talking about though, and it does work, but like the concrete crack issue, you gotta do the prep work. The cracks in concrete are much worse in areas where there are temperature fluctuations compounded with freezing and thawing, and water intrusion.
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.
I have been a professional caulker in California for over 45 years and have dozens of examples of polyurethane lasting 25+ years. The fact is VERY few professionals use silicone for flat work.( not arguing the top quality of those products or their validity.) Being used for highways ( vehicular traffic only)and mixed foot and vehicular traffic are two entirely different things. You will find VERY FEW municipal parking structures use silicone due to mixed vehicular and pedestrian traffic. For every parking structure that uses silicone ( if there are any) 100 use polyurethane. At least in California. If Sika or Vulkem lasts only 5-10 years it is due to poor installation.
I spoke with more than one technical rep at trempco regarding the vulkem ssl45. They unhesitantly said to not Sprinkle any sand regardless of playground sand or finishing sand or any kind sand) over the polyurethane ssl45 product because the product was not meant to have any aggregate (like sand) in it or on it. Sika company says the same thing - not to Sprinkle sand over polyurethane. Both companies say any kind of sand can cause premature or earlier degradation in terms of some possible surface blotches when the elastomeric polyurethane expands in hot weather and contracts in cold weather and interacts with the sand even though just a light dusting. It takes the product about a week to cure starting from the outside of what was applied and finally the inside - it cures 1/16 of an inch per day so if you applied 3/8 inch in the crack...3/8 divided by 1/16 = about 6 days at least or so.... about a week/7 days. It cures faster in hotter weather. Also don't apply if rain is expected in next 24 to 48 hours to have best result. And to have best results dont have any cars over it for couple days. Yes things might be fine if not waiting that long... but that's what they advised. I realize and they realize many trade people have sprinkled sand over ssl45 or sikaflex type polyurethane elastomer crack caulk products and even over silicone non sag crack products. They still say it's not good/advisable regardless what people do. I decided id rather not sprinkle any sand and possibly not have the color match as well - but have the product to have best chance to last longer. Also the playground sand i saw at home depot and lowes and mulch/stone specialty store was an ugly tan color that definitely did not match my gray concrete driveway anyway. There is also limestone dust that is concrete color (limestone is a common ingredient in portland cement) sold at mulch and stone stores. But definitely dont use that to sprinkle over the crack polyurethane caulk. I called a sales rep who sells limestone dust for a mulch/ stone company and he said when it rains or gets wet, the limestone dust would get sludgy .... and that wouldn't be good in interaction with the ssl45 type product. Limestone dust also hardens more than sand so another aggregate not meant to combine with. The vulkem tech rep said theoretically it can be painted over but only if the paint (whether acrylic or enamel or whatever) is made to go over polyurethane elastomer. But in reality there aren't paints at any companulies i could find made to go over/adhere to polyurethane elastomeric crack fillers. Gor example I called Benjamin Moore and they said they dont have any paint made to go over and stick to polyurethane elastomeric like vulkem ssl45 or any other polyurethane brand such as sika products. .... because it won't adhere and perform properly when the polyurethane expands/contracts. If there were such a paint, i was thinking to find a grey color to blend over the crack filled polyurethane ssl45 but no longer thinking of that. Trempco also said when you tape both ends of the crack to keep the material from running out, to not remove it right away and to be safe leave it on forv the 6-7 days it takes for ssl45 to fully cure. If the tape stuck it wouldn't be a big deal because likely wouldn't be seen or lawn edging could block view or because the tape would only be over the tiny crack width.
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!! :)
