The caulk in my bathtub is coming up and it is time to replace it. When the surround got put in a few years ago it didn’t look right but someone was in a hurry so it didn’t get checked. There is a 1/4″ gap all around the surround which I believe is correct, but it fans out to nearly 5/8″ at the edge of the surround. I have read about backer rod and it seems to be the right thing for the job before caulk. If I understand correctly I place closed cell backer rod into the big gaps until the gaps are nearly full. I then caulk as I normally would. The question is where do you buy the backer rod? I have found a few internet sites that will sell me 6000 feet, but I only need enough for 1 bathtub. Maybe 10′ of 1/2″ and 10′ of 1/4″. Can I get this at Home Depot or Menards, or is there something else I can use which will do the trick? I want to do this right this time, so that I don’t have to do it again anytime soon.
Thanks,
Scott
Replies
Any decent hardware store should carry it, and if a "home center" doesn't then you shouldn't even darken their door.
It's usually sold with the caulk, and comes in plastic "hook-hanging" bags roughly a foot square (looks like a wad of grey plastic tubing inside). MD is one common brand -- a sort of red chevron on their package, IIRC. Check the hooks near the caulk, or simply ask.
If you have a professional buider's supply in your town, they may be able to sell you only what you need. Ours here has huge rolls of different sizes and sells it by the foot. You want the rod to compress just enough to make solid contact with both sides of the gap. The rod serves two purposes: saving on caulk and providing a non-gripping surface for the caulk, allowing it to stretch and compress in one plane only.
HD has it. Look in the weatherstipping section, not near the caulk. Obvious, right?
Scott,
In the upcoming FHB there is an article on caulks and sealants written by yours truly. It was interesting that all the manufacturers I spoke with recommended using backer rod with their products, but I couldn't find it anywhere locally. I tried two HD's, a bunch of hardware stores and lumber yards and and a handful of paint stores. No dice. In fact I had to ask a manufacturer to send me some for photos.
At HD I was actually told, "Oh you don't need anything special just stuff some strips of wood into the joint!"
Google it and you'll find plenty of suppliers, but like you said you'll also likely have to buy more than you can use in a lifetime. But in your case I think it is worth finding some. Generally open cell is used inside, but in a bathroom, I would probably also go with closed cell because it is impermeable to water that does find its way past the caulk. It should be compressed in the joint. And on a tub surround I'd probably use a silicone K&B sealant.
Good Luck,
Brian P.
Thanks everyone. I couldn't find it at the local Lowe's (one block from the office) they got that dumb look on their faces when I asked, so I tried the hardware store two blocks from the house. Greatest place in the world to shop, but they always have to order everything I need. They had two sizes in stock so I bought both, one of them will surely work. Thanks to everyone for your suggestions.
Looking forward to your article in the next FHB Brian!
Stores that carry masonry supplies stock it.
Scott, I get backer rod by the foot at a concrete and brick products supply..........the largest in the area. I've never tried other locations but I would be surprised if all good masonry/concrete suppliers didn't have it.Remodeling Contractor just outside the Glass City.
Quittin' Time
Our local True Value usually has two sizes. Good Luck. Bob
Home depot does carry it. After explaining to 4 people what I needed one of them finally said "you mean caulk saver?". Thats right. thats what they call it. Its in the with the weatherstripping.