Deck-O-Seal 4701033 Waterproof Expansion Joint Sealant - High-Performance Roof & Deck Sealant for Concrete, Masonry & Metal - Ideal for Outdoor, Construction & Weatherproofing Projects

We bought a house with a pool and the expansion joint was a mess. Our first winter, we lost a bunch of tiles due to water freezing in the expansion joint and some online research led me to deck-o-seal. I definitely recommend backer rod if your expansion joint isn't nice and uniform and relatively shallow - I had many large gaps that took a decent amount of backer rod and would have been a huge pain to fill with this sealant. I waited until around the time we closed the pool at the end of the summer to do this job to maximize work time, which worked pretty well. Try to do it on a day that's not windy. It was breezy when I did it, and it was really tough to prevent bits of leaf and debris from getting stuck in the sealant as I applied it and it dried.When I took the cans out of the box - I ordered three since I didn't know how much I was going to need - every large can had a dent in the same exact spot from impact of the smaller can. There were some minor leaks that had dried on the outside of the can as a result, but it wasn't a big deal. Nearly everything you need is included in the box. You'll need a funnel if you don't want to get this stuff all over everything as you transfer it to the bottle. Luckily for me, I had one laying around that I use for oil changes and I just bought a new one for that purpose after I was done. If you don't have one, go to an auto parts store and pick one up before you open the cans. The other thing you'll need is paper towels. If you're messy like me you'll need a whole lot of them. Cover the surface you're mixing on with them and keep a bunch on hand while you're filling the bottle.Prepare yourself when you open the cans - this stuff smells absolutely awful. The description says you can use it indoors and outdoors, but I feel sorry for anyone that tries to use it indoors. Mixing it is fairly easy. You might want to have a few spare paint stirrers on hand since this it is quite thick - I broke one or two. As mentioned before, you'll need a funnel if you want to avoid making a complete mess, and even with one you shouldn't expect it to be clean. It was difficult to stop the flow of sealant quickly once you got it going out of the can. I used the little can to hold my funnel in between fills and catch the excess that slowly oozed out of it.Actual application was pretty straightforward. I cut most of the nozzle off for a bigger hole because the joint I was filling was large. In a lot of spots, the thick sealant gradually flowed around the backer rod, leaving what looked like a backer rod that had been dipped in sealant and placed in the joint. I had to go over many of these spots several times with about 10 minutes in between to get it to look right and set up flush between the deck and coping instead of curved around the backer rod. I ended up needing all three cans, but my pool is pretty big and my expansion joints were in pretty rough shape. It was a really tedious job, but it will probably be much easier for you if your expansion joint is in good shape.The end result looks nice and I'm definitely looking forward to not having to retile a bunch of spots in the spring. This stuff is pretty expensive and not a blast to work with, but it's definitely worth it and forms an effective and natural-looking seal. I absolutely recommend it.