PSA: Stop using self-tapping screws on metal roofing. Just stop.

I was up on a buddy's new shed last week out near Canyon and saw he'd used self-tappers to put his metal roof on. Told him those things will pop or strip out in a few years with our Amarillo wind and heat cycles. I know cause I did the same thing on my barn back in 2016. Had to replace half the screws after two winters. The rubber washer on self-tappers just doesn't hold up like a proper stitch screw with the neoprene bonded on. Cost me about $80 and a whole Saturday to fix. Has anyone else had a roofer try to sell you on self-tappers?

3 comments

3 Comments

shane_clark1mo ago

You're seriously overthinking this. Self-tappers with good rubber washers last just as long if they're the right grade and not the cheapo hardware store junk, I've got them on my place outside of Canyon since 2019 and not a single leak yet. Ever actually compare the shear strength numbers on the two types or just going off one bad experience?

park.miles1mo ago

I feel you on this one. Shane, I'm not trying to come at you hard, but I've seen the same thing the_susan is talking about. My neighbor did his whole shop with those good self-tappers from a legit supplier, not the cheap ones, and by year three the rubber on a few of them had started cracking and pulling away from the screw head. It's not about the brand or the grade, it's just how the rubber is attached. That bonded neoprene on the stitch screws stays put no matter what the sun and wind throw at it. I get that yours are holding strong so far, but out here on the high plains that UV is brutal. Hope yours keep working for you, I really do, but I'd rather not have to get the caulk gun out every few years.

the_susan1mo ago

Read a good article from some building science guys out of Lubbock that tested different screw types on metal roofs and the self-tappers with those little separate rubber washers broke down way faster than the stitch screws with bonded neoprene. @shane_clark you might have luck with yours so far but give it another year or two, especially with the wind and sun we get. The problem is the rubber washer on a self-tapper can spin or dry rot separate from the screw and then you got a hole with nothing sealing it. Stitch screws have that rubber bonded right to the metal so it can't move. I see a lot of guys on job sites grabbing the cheaper boxes and regretting it later when they're up there caulking every leak.