A wall-to-lower roof intersection occurs, for example, where a one story portion of a home meets a 2 story portion and where the walls of a dormer meet the roof.

Effective transitions in this type of intersection have been particularly problematic in high performance and DER projects because the proper location and sequencing of roof to wall flashing is "not the way we usually do it." In other words, careful coordination is going to be needed between contractors and roofing subcontractors to implement details that are different than what is done in "conventional" construction and renovation. It is also likely that planning and advanced preparation will be required.

When the water control layer of the wall is at the outer face of the insulating sheathing, the roof flashing must connect at the face of the insulating sheathing, not at the wall sheathing behind the insulation. This presents a sequence challenge if - as is usually the case - roofing is installed prior to the insulating sheathing and water control layer of the wall.

When the water control layer of the wall is located at the face of the existing wall sheathing and behind exterior insulation, the step flashing can be located at a familiar location (against the wall sheathing). However, kick-out flashing will need to anticipate the additional thickness of the insulation so that the kick-out diverts water beyond the face of wall cladding. Another consideration that factors into the design of the transition is future replacement of the roof. This will require access to the connection between the water control layer of roof and that of the wall - which is behind a thick layer of exterior insulation. Without clear access, a contractor replacing the roof at some point in the future might cut through the insulation layers (and probably the water control layer) or install the step flashing at the face of the foam insulation. Either of these would subvert the water control system implemented in the DER measure. A removable and labeled section of insulation just above the roof surface facilitates access to the step flashing.

Wall 1A to Attic 1

• Curb of insulating sheathing is necessary to support installation of step and kickout flashing in the construction sequence.
• While, in general, Attic 1 does not require removal or replacement of roof shingles or underlayment, this transition does require removal of existing roof shingles and underlayment along the intersection with the upgraded wall.

Wall 1A to Roof 1

• Curb of insulating sheathing is necessary to support installation of step and kickout flashing in the construction sequence.

Wall 1A to Roof 2

• Curb of insulating sheathing is necessary to support installation of step and kickout flashing in the construction sequence.
• While, in general, Roof 2 does not require removal or replacement of roof shingles or underlayment, this transition does require removal of existing roof shingles and underlayment along the intersection with the upgraded wall.

Wall 1A to Untreated Roof/Attic

• Curb of insulating sheathing is necessary to support installation of step and kickout flashing in the construction sequence.
• Existing attic floor insulation at the wall in the attic space needs to be temporarily removed to allow a continuous application of the closed cell spray foam from the roof sheathing down to the top of the ceiling below the attic floor joists.

Wall 1B to Attic 1

• Curb of insulating sheathing is provided to allow access to step flashing during re- roofing of lower roof at a future date.

Wall 1B to Roof 1

• Curb of insulating sheathing is provided to allow access to step flashing during re- roofing of lower roof at a future date.

Wall 1B to Roof 2

• Curb of insulating sheathing is provided to allow access to step flashing during re- roofing of lower roof at a future date.
• While, in general, Roof 2 does not require removal or replacement of roof shingles or underlayment, if there is no transition membrane at the intersection of existing roof and wall sheathing, failure to provide one will compromise the air control at the lower roof to wall connection.

Wall 1B to Untreated Roof/Attic

• Curb of insulating sheathing is provided to allow access to step flashing during re- roofing of lower roof at a future date.
• Existing attic floor insulation at the wall in the attic space needs to be temporarily removed to allow a continuous application of the closed cell spray foam from the roof sheathing down to the top of the ceiling below the attic floor joists.

Untreated Wall to Attic 1

• If there is no transition membrane at the existing wall to roof intersection, failure to provide one in the scope of the DER project increases the risk of air leakage at that intersection.

Untreated Wall to Roof 1

Untreated Wall to Roof 2

• If there is no transition membrane at the existing wall to roof intersection, failure to provide one in the scope of the DER project may increase the risk of air and/or water leakage at that intersection.