Quick fix or redo: dealing with damaged aluminum flashing

The trick is definitely in the prep and not rushing it.

Couldn’t agree more with this. I’ve seen too many “quick fixes” where folks just slap some goop on corroded metal and hope for the best - never ends well. But if you actually clean, dry, and prep the area, butyl tape or a patch can hold up surprisingly well, especially if you’re not planning to be there forever. Just don’t skip the prep, or you’re basically inviting leaks down the road. Keeping an eye after storms is smart - sometimes that’s all it takes to catch a problem before it gets worse.

I’ve lost count of how many times I’ve seen someone just smear some sealant over dirty, flaky flashing and call it a day. It might look fine for a week or two, but water always finds a way in if you skip the basics. My go-to is: wire brush off the crud, wipe it down (even a little rubbing alcohol helps), let it dry, then patch. If you’re in a pinch, sure, butyl tape can buy you time... just don’t expect miracles if you rush it. And yeah, after a big rain, I always check those spots - saves headaches later.

It might look fine for a week or two, but water always finds a way in if you skip the basics.

That line hits home. I’ve lost track of how many times I’ve poked around an attic and found a “quick fix” that turned into a long-term headache for the homeowner. One place I see this a lot is on low-pitch roofs - folks think a bead of caulk will do the trick, but it just traps moisture under all that gunk. The next thing you know, there’s rot in the sheathing and mold creeping along the rafters.

I’m with you on cleaning things up before patching. I’ll add: sometimes I see people skip checking underneath the flashing itself. Just because the top looks okay after cleaning doesn’t mean there’s not corrosion or even insect nests hiding underneath. Had a case last spring where someone kept slapping sealant over a chimney flashing - looked fine from above, but underneath, carpenter ants had chewed right through the wood. That was an expensive lesson for them.

One thing I’m curious about: anyone else notice that some of these newer “miracle” sealants actually peel faster than old-school roofing tar? Maybe it’s our freeze-thaw cycles here, but I’ve seen silicone-based stuff let go after one rough winter, especially if it wasn’t applied to bone-dry metal.

I do think butyl tape has its place as a stopgap, like you said. But if there’s already pitting or holes in the aluminum, sometimes it’s just better to bite the bullet and replace that section. It’s not glamorous work, but flashing is one of those things where shortcuts always seem to catch up with you.

Curious if anyone’s tried using those peel-and-stick flashing membranes as a backup layer under aluminum? I’ve seen mixed results - sometimes they help, sometimes they just trap water if not sealed well at the edges.

Anyway, totally agree about checking after heavy rain. A little paranoia goes a long way when it comes to leaks...

Curious if anyone’s tried using those peel-and-stick flashing membranes as a backup layer under aluminum? I’ve seen mixed results - sometimes they help, sometimes they just trap water if not sealed well at the edges.

I’ve run into that too. Tried a membrane under aluminum on a green roof retrofit last fall - looked promising, but after a wet spring, moisture still got trapped at the seams. It’s tricky, especially with all the expansion and contraction. Sometimes I wonder if we’re just creating more places for water to hide.

Sometimes I wonder if we’re just creating more places for water to hide.

Totally get what you mean. I’ve seen those membranes work, but only when every edge is sealed up tight - and even then, expansion can mess with things. On one job, we thought we had it nailed, but a tiny gap let water in and it just sat there. It’s frustrating, but honestly, figuring out where water might sneak through is half the battle. You’re not alone - sometimes it feels like a guessing game.