Weatherproofing lean to shed attached to stucco wall

[tom coleman]

I am building a 4x8 lean to shed that. The back of the shed is the stucco wall of the back of my house. Roof rafters will be screwed/glued to a 2x6 that is subsequently lagged to the stucco wall. It would be nice if I could tuck flashing beneath house siding before shingling the shed roof but there is no house siding. How to waterproof the joint between roof ledger and house back wall?

[Jamie Buxton]

How tall is the stucco wall? If you can make the top of the shed close enough to the top of the wall, the roof overhang protects the seam between the shed and the wall.

[Bill Rogers]

Not in the "liquid" Sunshine state!!

[Thomas Bank]

What you want to use is a reglet. If building from scratch, you'd use one of these under the bottom edge of the stucco: http://fryreglet.com/details/roof/pop/165.htm

But with the stucco already installed, it would probably be easier to use a surface mount reglet than to cut away the stucco and try to get the reglet underneath: http://fryreglet.com/details/roof/pop/164.htm

[Bruce Wrenn]

If house has REAL stucco, not stucco over foam, the use a straight edge guide to cut a slot in stucco, about 1/4" - 3/8" deep with a diamond blade on a circular saw. Have a sheet metal shop break some flashing so the lip would fit into slot, then drop down wall a couple inches, and then turn out over roof about 6". Fill slot with a nonhardening caulk, like what is used in tilt up concrete construction. I prefer to NOT use silicon. Then insert lip into slot with caulk, and fasten flashing to wall using suitable screws with neoprene washers under heads.

[joe milana]

Both the reglet & the flashing suggestions are good ideas, but you'd never get away with lagging directly to the stucco here. I would have to remove the stucco, flash honoring the existing water plane, & attach the ledger directly to the existing framing.