Do I Install Roof Trim before Shingles?
Roof trim is a general term for many parts of the roof that must be installed when shingling a roof. Most roof trim is installed before shingling but not all of it.
Rake board trim is an overhang from a pitched roof. It can be simple board or it may include a frieze board, soffit and fascia. The rake board serves as the starting place for the shingles. The "L" channel of the rake provides a straight line which is the guide for beginning each course of shingles.
Other Roof Trim
Roof trim includes the flashing for the eaves and gables. It is secured every 10 inches along the eaves and roof gable. Another part of installing the roof trim is setting in the pipe vents and their flashings. These elements should be in place prior to placing the shingles so that the shingles can be installed properly around them.
Cap trim is one trim that is installed after the roof shingles are in place. It is the final step in finishing the roof. At the peak of the roof the shingles are not overlapped. The cap keeps moisture from leaking into the roof at the peak.