Flashing a Metal Roof Where It Meets a Sidewall

Where a roof meets a wall is the most common place I find water getting in. It is not the panels that fail there. It is the flashing.

Sidewall flashing is a bent piece of metal that sits against the wall, runs up behind the siding, and laps out over the roof panel. Water that comes down the wall hits the metal and is carried onto the roof instead of behind it. For that to work, the flashing has to go up the wall far enough and tuck under the siding, which means the siding comes off and goes back on. Here's where installers cut corners: they leave the siding alone and run a bead of sealant along the joint. That holds for a few seasons and then it does not.

In this video I walk through how we set the flashing, how far up the wall it goes, and how the siding is replaced over it. If someone quotes your roof without mentioning the walls, ask how they plan to flash them. The answer tells you a lot. Now you have the context to ask.