I have a shower where the caulk around the door was moldy, so I scraped out the old caulk and am getting ready to apply new caulk.

But all the bath/shower caulk I have is old and dried up. I do have a tube of "Through The Roof!". I don't want to have to go to the store so I'm wondering if I can just use that?

I figured if it can seal just about any material related to a roof, and is waterproof, etc., why wouldn't it work for a shower?


1 Answer 1


It might be marketing, or it might be fact (or both!) but caulking that's designed specifically for kitchen/bath applications has an anti-microbial element.

Assuming your existing roofing caulk isn't too old, it would probably work. It might stink more than expected for a little while.

If it was me, I'd get a fresh tube of kitchen/bath silicone from a place that has frequent inventory turnover.

Edit: Two other things, based on a quick read of the Through the Roof brochure… it has a long cure time (24-48 hours), which might not be ideal inside. I haven’t used this specific product, but it reminds me of others that are really tough to work with (compared to normal silicone), so wear disposable gloves and use masking tape to establish the edges of your bead.

  • 1
    +1Very important to check the expiration date. I just had to re do a shower caulk job because the caulk I used was old and would not cure properly! A real mess
    – Kris
    Aug 26, 2021 at 12:05
  • 1
    Wow, good info! I never thought about an expiration date on caulk. That could explain the cracking I've got in a bathroom update I did just last summer. I thought that it might have been from too thin a bead, but I did use a tube of (previously unopened) caulk that I found in the garage. Thanks, I don't feel so bad now!
    – FreeMan
    Aug 26, 2021 at 14:16

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