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 overwhelm the width of the flashing and because it.
Roof shingles against wall.
Galvanized sheet metal bent at a 90 degree angle i e.
Drive two type 316 stainless steel nails through the shingle and into the wall with a hammer.
Place one shingle against the wall with the wider bottom edge aligned with the bottom edge of the wall.
Set the top of a shingle level with this line and mark the bottom for the angle of the roof.
Here is an attempt though maybe not a very good one to make the roof flashing serve also as a through the wall flashing with a tile roof.
Flashing is installed to surround roof features such as vents.
Step 8 nail the flashing into place using galvanized roofing nails.
If there were no flashing against these walls water could slowly drip into the crevice between the wall and the roof and potentially into the home.
How to install roof flashing against a wall.
The wall portion of the flashing should be flush against the exterior wall and the shingle portion of the flashing should be on top of the porch roof shingles.
Bent into an l shape.
Damaged or improperly installed roof flashing especially around the chimney or dormer is one of the most common causes of roof leaks.
Snap a horizontal chalk line about shingle height on the side walls where the roof intersections slope.
The correct installation of flashing at this juncture is critical in order to maintain a weather tight seal.
It is not uncommon especially in two story and side split houses to have a roof that butts against a wall as shown in figure 1.
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.
Cut the bottom to that angle and nail the shingle in place butted up against the edge of the front wall shingle.
Keep the nails as close to the edges of the flashing as possible.
Step flashing is used to provide a water tight connection where roofing adjoins a vertical juncture.