Black Backer Rod, Rubber Caulk Saver Concrete Filler Rope Weather Stripping for Gaps and Joints (Diametre 1/4in x Length 16.4ft)

I used it to seal the gap in the partially open window with a window air conditioner, the window slides horizontally. The gap is between the sliding window and the fixed window. Works good, just the right thickness.

The idea is to use this instead of expensive caulk to fill concrete cracks. It is a reasonable idea, but there are some caveats. I should have studied up on YouTube or something, because I ran into trouble right away.These sort of products need to be held mechanically in place by being wedged in. I didn't have that circumstance in the particular spot I chose to use this, rather it was a wide V groove expansion joint I wanted to cover over - the "rod" just lay in the bottom of the groove. So two problems with that: 1) The product was delivered in a loose bundle, which it remembers the turns, so it can't be pulled actually straight - it waves up and down every so often. (I'd thought, as I was fighting with it, that I should have strung it up in the sun outside for a couple of days - tight like a clothesline). 2) This product is denser than the LowDepot variety (which is larger diameter), but it is still lighter than the caulk. Thus, if it isn't wedged in, just lying in the V, it wants to float up.The better way for dealing with a V, if you are using this type of product, is to prep it by sticking it down with fast setting Construction Adhesive on the ends at least, with a bit more here and there as needed. Pull it tight, and weigh it down. Let that set up for an hour or few, then go in with the concrete patch goo.If you are cheap and have lots of time, there are alternatives to this product. In one area, I got frustrated and used some coarse sand and made a goo aggregate. This doesn't float and sets up into a really hard fill, not squishy. It was sort of suggested by the caulk vendor - they said to fill cracks with sand if it is more than a certain depth. In my case I already had goo in the crack, so I couldn't put sand under it; I had to mix it. That works really well, however, it is very time consuming and hard to control and contain. I also experimented with using a fresh razor sharp utility knife to slice long V segments from a pool noodle. This also worked (no coil curl and allowed fitment for crack variation), but it was lots more time invested, similarly prone to floating if not wedged, and did set up rather squishy.Bottom line: The product is what it says it is and will deliver good results if used within its limitations. However, unless you read this or look online elsewhere, you'll not be helped by any product instructions as there were none.

Used to seal a seam in the bottom metal fireplace frame that was causing cold air to leak into the house during winter. Was the perfect solution.

I like the rubber better than the foam for doing thin joints. This will proved a savings on the poly sealing to liquid proof the bottom of the sheetrock. Also keeps critters out.

I needed this and i didn't know anyone sold this. Great insulation properties. Great price.

More than enough for job, great for sealing cracks

I am not sure how this will perform since it doesn't compress and expand like a closed or open cell foam you'd get in a more traditional backer rod. This is really dense so it I'm not sure how it will perform in weather fluctuations. I needed a backer rod to fill in before caulking and adding trim around several skylights. On one I used an open cell backer rod that will expand and compress in heat and cold, but the other one had a much smaller gap. I thought this would work when I ordered it, but I'm a little nervous about it will ultimately perform. It's in place and caulked in, but it's nothing like closed cell foam. Possibly, it's a better choice, but the listing calls it a closed it foam when it's really a synthetic rubber (EPMD- You gots to chill).I'm giving it 4 stars because I think I've used it correctly and that it will work for what I need, but the listing is unclear as to the product and its uses. It needs to be caulked in place, not just laid out on a deck as though it's some kind of sealant in itself. Also, it is not a "rope caulk." Rope caulk, if that even still exists, is actual caulk in a rope shape that you smoosh into place, and it functions like caulk. It does not need to be caulked into place because it is caulk, and this is not caulk. It's fake rubber in a tube shape that doesn't compress like foam and doesn't seal like caulk. The listing needs to be more clear.

I used this to fill in a gap at the bottom corner of my door. Works well.