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.
How to roof against a wall.
Follow the photo for illustrated instructions.
Housewrap creates the foundation.
In an existing construction you might have siding whether it be vinyl wood or brick.
Metal step flashings are pieces of metal that are shaped like an l at least 5 inches wide and tall and 8 inches long as shown in figure 2.
For areas where the walls meet the roof you will need to use the step flashing technique.
Even though roof flashing is one of the most important elements of a roof not many people know how to install roof flashing against a wall properly.
On lean to roofs where a sloping roof plane meets the siding endwall flashing is necessary to prevent leaks.
Figure 2 step flashing.
Normally this wall would have a house wrap on it like tyvek.
To tie the roof into the siding the tin roofing panels must first be installed to.
In this case we ve gone against new construction.
Metal flashing also called roof flashing goes against a stucco wall to protect it from water damage.
If the roof runs flat up against the brick wall you must install the roof side of the flashing either under the last layer of shingles or over the roof material if it is metal.
Ideally i like to start by installing a 3 ft.
The proper installation of flashing at the point where the roof meets wall is to use metal step flashing.
Figure 1 roof plane butting against wall.
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.
Sheet of housewrap or even better a piece of self adhering roof underlayment to the wall before the first truss or roof rafter is placed against it.
The sheet acts as a backup at a vulnerable junction.
Flat roof and flashing against brick wall install base flashing under shingles or over metal roofing material.
A corner flashing piece can either be bought from the hardware store or it can be made using a regular step flashing piece.
There you have a z trim and an end wall flashing that have been joined using a stitch screw.
A roof or wall that is not properly sealed off from water can be extremely costly to fix not to mention the hassles that accompany the unwanted water.
Below are two photographs of roof wall step flashing completed and effective of a slate roof against a brick wall below left and in process with step flashing against a dormer sidewall before the dormer siding has been put in place below right.
