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New / Updated Content

Revised January 12, 2014

   roofkey Roofing Guidelines  Roof Inspection Service Fee  Roof Inspection Service

 



Eave to Rake Wall Flashing

 

One of the most troublesome areas of the roof is the Eave to Rake Wall Flashing intersection.  However, the problems in this area can be greatly reduced if some guidelines are followed.

Below are Guidelines for Flashing the wall before installing any type of Sloped-Roofing Material at Eave to Rake Wall Intersections.

 

2D Z Bar eave to Rake Wall 1

Before installing any roofing material, make sure that others before you have correctly completed their job with the Fascia Trim Board and Roof Decking intersection.  This intersection should look as sketched above.  See Eave Framing/Trim Problems web page.

 

2D Z Bar Eave to Rake Wall 2

A piece of Vertical Blocking/Backing Material is installed at all Roof to Wall Intersections.  This Vertical Blocking/Backing Material will vary in thickness depending on the thickness of the Cladding.  It can be equal to the thickness of the Cladding/Siding or slightly less but never thicker than the Cladding/Siding.

How far up the wall the Vertical Blocking/Backing Material extends will vary depending how high up off the roof deck the roofing material's surface is.  The minimum height of the Vertical Blocking/Backing Material is 5 1/2", the dimension of a Nominal 6" board.  A Nominal 2" x 4" board is only 3 1/2". This is too short for even the minimum roof flashing height of 4" up the wall that is required by some roofing materials. 

The end of this Vertical Blocking/Backing Material must extend down the wall and be flush with the outside face of the Eave Fascia Trim Board as shown above.

 

2D Z Bar Eave to Rake Wall 3

The standard eave roofing materials are then installed turning the Ice & Water Membrane up the wall a minimum of 4".  See Eave Roofing Material Installation web page.  Sandwiching the Eave Metal Drip Edge between Ice and Water Membrane is always a good idea.

 

2D Z Bar Eave to Rake Wall 4

The Underlayment is also turned up the walls a minimum of 4" on the outside face of the Vertical Blocking/Backing Material.  Shown is a two ply Underlayment installation which means that it is applied shingle fashion.  Example: a 36" wide underlayment is lapped 19" to obtain a true 2 ply installation.

 

2D Z Bar Eave to Rake Wall 5a

The Through the Wall (Z Bar) Flashing is placed over the Vertical Blocking/Backing Material.  By the way, the Underlayment can be installed anytime, even after the placement of the Through the Wall (Z Bar) Flashing.

 

2D Z Bar Eave to Rake Wall 5b

This closeup sketch shows details of the intersection of the Eave to Rake Wall. 

 

2D Z Bar Eave to Rake Wall 5c

If the Cladding/Siding includes a Weep Metal Edge, it is next installed over the Through the Wall (Z Bar) Flashing.

 

2D Z Bar Eave to Rake Wall 5d

This Weep Metal Edge is placed about 1/8" to 1/4" above the top of the Vertical Blocking/Backing Material to provide positive drainage onto the Through the Wall (Z Bar) Flashing.  Setting it down directly on the Through the Wall (Z Bar) will block the weep holes.

 

2D Z Bar Eave to Rake Wall 6

Next the house wrap is placed over both the Through the Wall (Z Bar) Flashing and the Weep Metal Edge.  

 

2D Z Bar Eave to Rake Wall 7a

Now any moisture that gets in behind the Cladding/Siding will drain down the wall House Wrap onto the Through the Wall (Z Bar) Flashing and onto the roof surface once the roof flashing and roofing material is installed.

The Roofing Material and Roof Flashing can be installed at any time with ease.  If the roof ever needs to be replaced, the new Underlayment and Roof Flashing can easily be installed without disturbing the Cladding/Siding.