View Full Version : how to seal downspout joint
I have a leaky downspout joint and tried sealing it from the outside, but it still leaks. Is there a way to seal it from the inside? Some kind of flexible applicator or brush? I think it has a better chance of not leaking if sealed from the inside.
Galvanized metal 2x3, inside miter, shoe joint
11-04-2005, 03:56 PM
sounds like the connection is backwards. the upper leader should be inside the lower. then the only way it could leak is if it was clogged.
not clogged, just old. at least a dozen years if not more, though not sure since not the original owner.
don't know if the connection is backwards and not inclined to unsolder the joint to find out. but i don't think so, since it hadn't leaked before now.
any tips on sealing it from the inside?
Anna since you say 'a leaky downspout', that would suggest the pipe that attaches to the gutter/eavestrough. That is why it was suggested it was reversed " lapped".Normally if they are lapped properly (upper edge INTO lower) they never leak unless filled with water by being plugged up.
But I think what you are referring to is the main horizontal gutter/eavestrough and is right at a mitred corner joint/s.
Your local hardware store has various sealants for this. Make sure you DRY and CLEAN the joint real good on the INSIDE before applying.