I will be replacing a section of gutter on a barn in a month and was wondering what the best method of joining the sections is. I will have limited ergonomics working in a lift about 27 ft off the ground, this will be about 40 ft length of gutter. I have 10-ft sections of galvanized steel gutter on order. My thinking is that I'm going to rivet the sections together, maybe overlap by 6 inches, use a liberal amount of silicone sealant. Resistance spot-welding or soldering seems to be common for galvanized steel gutters but no mention is ever made of the increased tendency for rust happening at the joints due to the zinc coating being blown away by the heat. Working with heat directly at the eve / roof-line is also a fire hazard. So any thoughts on this?

  • 1
    Yes, avoid welding on galvanized metals. Provide gutter support at the joint then screw, or Revit, the sections together. As long as the slope is adequate, the water dripping from the seam will be insignificant.
    – r13
    Sep 13, 2021 at 1:15
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    Silicon sealant wears out. They make special sealants for gutters. BTW: I've never seen a soldered gutter connection rust. That's probably why you've found no references to that happening. Sep 13, 2021 at 4:44
  • I'm no expert but a 6" overlap seems to me to be significant overkill. IIRC, the "butt joint" pieces for aluminum gutters only lap about 1", as do the downspout funnels, etc. I'd think that if it's good enough for AL, it's good enough for steel, so long as its got a good coat of sealant between them and the water flows from the top piece to the bottom piece (i.e., don't make present a dam to the water flow, but a waterfall).
    – FreeMan
    Sep 13, 2021 at 16:28

2 Answers 2


The normal method is aluminium pop-rivets and "roof and gutter" silicone. such joints seem to last the life of the gutter.


Solder is certainly the way to go for the best joints, but given that you are using galvanized steel, its also a bit of an overkill as that joint will outlast the rest of the gutter by a lot (unless you're painting it). Solder will not increase any rusting as it does not remove the galvanized coating. Spot welding or welding does and would.

Rivets and sealant on 1-2" overlap are sufficient, no need for 6". That's how its done on aluminum gutters, no need to reinvent the wheel.

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