I’m recaulking the top edge of the bathtub. The old caulk and loose grout are gone, but the gap is too large to fill with caulk alone.
The largest section of gap is 3/16″ across and 3/8″ deep, and the rest is not much smaller. I couldn’t get the backer rod (3/8″) to fit into the gap.
One website said that
(a) caulk should adhere to the sides of the gap but not the bottom. Too much contact area leaves the caulk less flexible and more likely to pull away from the sides.
(b) as it cures, caulk shrinks and is released by the backer rod, leaving just two areas of contact for more flexibility.
Assuming that’s true (but I haven’t heard it anywhere else), what else can be used in the gap? Should I backfill it with grout or mortar?
Janet
Replies
You can buy foam window or door weathrstripping, usuallu square section and black, at HD & Lowes. Leave the paper backing on and push it into the gap with the paper and sticky side ttoward the back. They are correct that you only want the caulk to adhere to two sides, and not fill the groove.
"Put your creed in your deed." Emerson
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
What Fasteddie said provided you cannot find 1/4" backer rod.
PLUS, once you have the caulk backer in place -- fill the tub with water and stand in it while you caulk. Leave water in tub while caulk cures. Drain water.
Caulk compresses better than it stretches without breaking any bonds.
Jim
Never underestimate the value of a sharp pencil or good light.
I agree with the other posts.
But this is important - what are you using for caulk?
Remodeling Contractor just on the other side of the Glass City
I just bought "DAP¯ KWIK SEAL PLUS¯ Premium Kitchen & Bath Adhesive Caulk w/MICROBAN¯", solely because it was available in tints. I also have GE Silicone II in clear and white, but decided not to use them. Clear would show the gap (or its shadow) and white would make the uneven edge of the tile more noticeable. Can I layer different types of caulk? That is, use the tinted caulk to camouflage the backing and uneven edges, topped by silicone caulk because it won't mildew.
You generally can't get one caulk to stick to another, especially with silicone.
If your view never changes you're following the wrong leader
Look in your Yellow pages for a concrete accessories supply. The places that sell rebar, wire mesh, sono tubes, cur'n seal, etc. Not your local big box or hardware store. The supply source will have backer rod from 1/4" to 1 1/2" or larger in 1/8" increments, and sell it by the foot.
I always buy more than I need cause it is so cheap.
Anyone come up with a decent storage method for unused backer rod?
Dave
Large freezer bags. Zip locking, place to write the size on. Will hold about 25' depending on diameter.
They can't get your Goat if you don't tell them where it is hidden.
That's much better than my system that in fact does work pretty well.
In a full sized garbage bag place the half dozen coiled like climbing rope bundles of backer. Fold the air outta the bag and slide (push) this package on left rear side of van, back behind the AdrianSteeler tool cabinet. Keeps the drywall square pole sander stuffed in there from rattling around.
thanks A great place for Information, Comraderie, and a sucker punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Thanks for the tip.
I use ziplock freezer bags for lots of odd ball parts, just never thought of the larger size for backer rod storage.
Dave
Dave,
Dovetail has it right.
Bags don't have to be the 2 gallon size though could be.
I use 1 gallon size for 25' - 50' of 1/4", 3/8" or 1/2".
Jim
Never underestimate the value of a sharp pencil or good light.
> concrete accessories supply will have backer rod from 1/4" to
> 1 1/2" or larger in 1/8" incrementsThanks, Dave, that's what I'll do. Janet
Yeah, what you read is entirely true, and understanding it is key to getting a good, reliable joint.
Any flexible material will work for backer -- you could stuff tissue in there if you wanted. But foam is better since it's less apt to mildew/rot if a little moisture gets through. As stated, weatherstripping foam is one option, as is simply slicing the rod with a razor blade.
slicing the rod with a razor blade
Maybe he's not allowed to use sharp tools. but that's a great idea. Wish i had thought of it."Put your creed in your deed." Emerson
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
I thought that the rod had to stay intact...something about the closed cells staying that way.
Nah, you can let a few prisoners escape.
If your view never changes you're following the wrong leader