Sikaflex Self Leveling Sealant, Gray, Polyurethane with an Accelerated Curing Capacity for Sealing Horizontal Expansion Joints in Concrete, 10.1 fl. oz Cartridge (Pack of 4)

This stuff is the best. I decided to fix a bunch of cracks on my 20+ year old driveway and to clean and fill expansion joints. This product levels very well and seals up completely within 24 hours. It is significantly better than all of the other crack fillers that I have tried. Highly recommended!

Works great, self leveling, fills the cracks. Great for amateurs!

If you’re looking for a sealant that combines ease of use with long-lasting performance, look no further than Sika Sikaflex Self-Leveling Sealant. This product has transformed my concrete surfaces, providing a clean, durable, and professional finish with minimal effort.Why I Love It:• Self-Leveling Magic: The true beauty of this sealant lies in its self-leveling properties. Once applied, it flows smoothly into joints, creating a flat, even surface without the need for tooling. This feature is particularly beneficial for those new to sealant applications, as it reduces the chances of uneven lines or missed spots.• Durability That Lasts: After curing, the sealant remains permanently elastic, effectively bridging gaps up to 1.5 inches wide. It’s designed to withstand the rigors of daily traffic, weather fluctuations, and the wear and tear typical of high-traffic areas like driveways and garage floors.• Quick and Easy Application: The product is a one-component polyurethane sealant, meaning no mixing is required. It’s available in both 10.1 fl. oz. and 29 fl. oz. cartridges, catering to various project sizes. The application process is straightforward—just clean the joint, apply the sealant, and let it level itself.• Paintable and Weather-Resistant: Once cured, the sealant is paintable with water-based, oil-based, or rubber-based paints, allowing it to blend seamlessly with your existing surfaces. It’s also waterproof and resistant to aging and weathering, ensuring long-term performance.Tips for Best Results:• Surface Preparation: Ensure that the joint surfaces are clean, dry, and free from oil, grease, or any other contaminants. This will promote optimal adhesion and longevity of the sealant.• Use Backer Rods: For deep joints, consider using a backer rod to control the depth of the sealant and prevent excessive use.• Curing Time: Allow the sealant to cure for 3 to 5 days for full strength. During this period, avoid any traffic or disturbance to ensure the best results.

I bought this to seal up the expansion cuts in the garage concrete. I noticed a while ago that the expansion cuts had done their job and there were cracks in the bottom of each cut, probably going down through the whole slab. I've got some radon issues here so i wanted to get something I could apply that would drip down and flow well enough to get a reasonably air tight seal in the cracks.I had to use quite a lot of the sealant but it did flow from the top of the cuts down to the bottom (the cut was too narrow to get even the smallest part of the tip inside it). The cracks are narrow enough that it didn't flow down the crack itself. I would not bet on that always working because this stuff is very runny and can easily flow down a crack. Fortunately the cracks at the bottom of my expansion joints are very small.It cleans up well off the sealed concrete in my garage. I'd hate to think about cleaning this off rough outside concrete. It's definitely not cheap but it's the kind of thing I want to only have to do once so a quality polyurethane seems like a good choice given that I may eventually paint the garage floor. For outdoor applications, where there's no chance I'll paint it, I may opt for silicone based because it resists UV better.

I really like this stuff. It flows and self-levels very well but that quality means some advance planning makes things go much smoother.My advice is to keep the box it came in and when you go to apply it cut off the box flaps from the side you opened and put a grocery store plastic bag in the bottom of the empty box. Also, have paper towels handy. The reason for this? Unlike caulk, when you stop pumping this stuff out and it quits flowing it still drips for a long time, even from an "empty" tube. When the tube is empty immediately point the spout up, remove the tube from the caulk gun and throw it in the box you kept.Also, when you stop pumping this stuff out it takes a while for it to stop flowing like caulk does, but even then, if you point the nozzle down it will slowly flow out of the tube. It is handy to have one of those cardboard flaps you cut off to immediately slide under the nozzle as you lift it up from the job. Get the nozzle pointed up and have a paper towel ready.Also, if you use a backer rod, make sure it is a tight fit. I had one spot where the backer rod barely touched each side and this stuff apparently flowed through a bit. I had a dip in edges in that spot as it cured. If the backer rod is not reasonably tight I suggest putting a little coarse "play sand" on the sides of the backer rod (where the backer rod curves down and meets the concrete on each side).You can ignore all that and still get a great result, but you might then spend a good while cleaning up.

This product is not for sealing vertical cracks and joints, horizontal only. I have a few wide gaps between slabs in my driveway and I was told that could undermine it and cause it to sink. I got some sand and filled in the gaps, leaving a half inch depth at the top. You put this stuff in your caulking gun and then basically just pour it in. It's a little thicker than honey and it will flow and fill in the area so you don't need to be as precise as with regular caulk. Just move along, allowing the caulk to ooze out as you go. It is self leveling and self sealing because it flows and makes contact with all the sides. It is supposed to remain stretchy and keep the water out for a long time. I can't say anything about that because I only just applied it but it has dried to a rubbery consistency and it looks great.