My Shed Stayed Dry in Normal Rain for Three Years. Then One Storm Told Me What I'd Missed.

The Fifteen-Dollar Fix

The answer was caulk. Not just any caulk—exterior polyurethane sealant, the kind that stays flexible through freeze-thaw cycles and bonds to metal.

I picked up a tube of DAP Dynaflex 230 at Home Depot for about $6. You could also use Sikaflex or Loctite PL S30. The key is “exterior grade” and “paintable” if your trim is painted.

The job took me maybe forty-five minutes, most of that cleaning the joint with a wire brush and wiping it down with rubbing alcohol so the sealant would actually stick.

I ran a smooth bead along the seam where the drip edge met the rake trim, both sides of the shed. Tooled it with a wet finger to press it into the gap. Let it cure for twenty-four hours.

Total cost with the caulk, a $4 caulk gun I already owned, and the alcohol: under fifteen dollars.

When to call someone: If your drip edge is rusted through, if the fascia behind it is rotted, or if you’re seeing daylight through gaps bigger than a quarter-inch, you’re past the caulk stage. That means removing trim, possibly replacing sheathing, and reinstalling everything properly—worth paying a roofer or carpenter to do it right.