Starter Course

The starter course (or starter strip) is the strip of roofing installed along the eaves before the first visible row of shingles. Without it, water could run through the cutouts and joints of the first course straight onto the deck. A starter also provides a line of sealant that holds the first course down in wind. Starter strips are commonly installed along the rakes as well.

Materials

Starters may be purpose-made strips with a factory sealant line, or field-cut from standard shingles with the tabs removed. Wood shingle and shake roofs start with a doubled first course, and tile roofs start with eave closures or a raised fascia.

Asphalt shingle details

Canadian guidance describes:

• a starter at least 225 mm (9 in) wide with an adhesive strip;
• hand-tabbing to the first course if there is no factory sealant;
• starter end joints offset from first-course joints by at least 125 mm (5 in); and
• an overhang of about 19 mm (3/4 in) at eaves and rakes, or flush with a T-type metal drip edge.

Common US practice is an overhang of 1/4 to 3/4 in (6 to 19 mm) past the drip edge. Guidance based on the IBHS FORTIFIED programme limits the overhang to 1/4 in, sets the starter in roof cement or uses a self-adhered ASTM D1970 starter, nails it 2 to 3 in above the eave and laps rake starters over the eave starter by 3 in.

When a 3-tab shingle is used, the exposed tabs are cut off and the sealant strip is placed nearest the eave so it bonds to the underside of the first course.

Common faults

• Starter installed with the sealant at the top instead of the eave.
• Joints in the starter lining up with joints in the first course.
• Nails placed where they show through the cutouts of the first course.
• Too much or too little overhang, leading to blow-off or water running onto the fascia.