Ok To End A Roof Into An Existing Wall
Yes even flat roof to wall intersections are not being properly done.
Ok to end a roof into an existing wall. The loss of roof coverings and roof decking can allow water to enter a building and damage or destroy interior finishes and contents or even worse may destabilize a structure and lead to building collapse. Butt the first new truss against the old one. A common problem area is the point where a gutter dies into an adjoining wall as the photo below illustrates. You ll need to remove the existing shingles and cut.
If you re adding to the gable end of the house the side wall that goes up to the roof s peak it s fairly easy to extend the existing roofline over the new space says curt schultz a realtor architect builder in pasadena calif. As long as you use a roofing design that matches your existing roof you can use the same materials. Remove existing siding and shingles at roof wall intersection. Tying in to an existing gable roof tie into the end of an existing gable roof by removing existing facing boards wall siding and any other obstructions back to the first truss of the old roof.
Then mount new trusses on the new addition walls. The flat roofing material must go up the wall a minimum of 12 or up the wall and over the top of the wall if the wall is less than 12 high. Remove and repair any damaged siding and sheathing next to or beneath the roof wall intersection. Install liquid water proofing or peel and stick membrane on walls next to and beneath the end of the roof wall intersection.
Tear roof sheathing from supporting framing see figure 7 4 and rip roof framing from supporting walls. The up slope end of a simple shed roof that rests near the eaves of an existing roof can usually be supported by the rafters of the old roof. Unless you re careful step flashing can allow water from the roof to slip behind the gutter and get behind the siding and even the housewrap. Install step and kick out flashing at roof wall intersections.
That s a simple low cost solution that can tie in well with the main house. Pick roofing materials that match your existing roof. The exterior of a house presents plenty of opportunity for leaks. And in our experience when a single piece of flashing extends only a few inches under the shingles especially on a long roof slope and worse on a roof that happens to slope slightly towards rather than away from the abutting vertical building wall the accumulated roof drainage water near the bottom end of the roof wall intersection will.