SIKA Closed Cell Foam Backer Rod, Gray, 3/4" Diameter x 20' Long, Water-Resistant Joint Filler for Sealant Application, Flexible and Durable for Cracks and Joints

Excellent product

I have several leaky spots in my house from settling. I didn't want to use spray in foam as it is so messy. The main reason I bought this was for a sliding French door that I can't quite get latched tightly enough. I don't want to have a contractor have my house opened up to fix this in dead winter. Especially when it's been below 10 degrees for the last week. This filled the bill quite nicely. Easy to use and about the same price or slightly less than the big box stores.

Squeezes into expansion joint that was 1/2 inch nicely.Since this joint was deep I also put some sand in first.Then the foam backer installed nice and snug.Then the self leveling caulk joint filler, worked great.

It's basically dense styrofoam with great elasticity that allows you to squeeze it into cracks. It works well as intended. It doesn't rip off easily, which is what you want.

it’s a three-quarter inch round long foam tube. Bendable. And I stuck it up under my aluminum siding that begins at the concrete block foundation because I thought maybe air was coming through making the living room cold

Did the job well!

Good backer rod. Closed cell and dense. The correct diameter. Seems very well made. Buy and use with confidence.

On the item, manufacturer recommends to twist two pieces together if gap is over 3/4“.This is not a solution! The sealant will completely run down thru the twisted rods, resulting in 100% loss of sealant.I lost five tubes of sealant.I ended up cutting pool noodles to the size I needed for remaining gaps, which was cheaper and just as easy to use. I could not find any local stores that carrIED the larger rod.Lastly, my sidewalk had a slight tilt, and since this sealant is self-leveling (which it works perfectly), the sealant slid to the lower side, resulting in undesirable results. Please only use on cracks that are level!