Installing slates reaching into valleys and rake edges is best done utilizing the widest slate possible for nailing strength, ease of installation and overall improved stability. Installing slates from the valley & rake edge working towards the middle of the field on valley courses can offer an ease of installation. Cut top corner of interlayment at 45° angle to help divert water into the valley and lap interlayment over valley. Lap interlayment over rake metal edge. Ensure a 6” lap on all interlayment course joints.

Installation Tip: Work from the OUTSIDES toward the MIDDLE on valley courses.
Trim top corner of interlayment at valley intersection at 45° angle.
Lap interlayment over valley metal.
Lap interlayment over rake metal.
Installation Tip: Cut wider VALLEY slates for easier installation and improved stability.
Installation Tip: Use wider RAKE slates for easier installation and improved stability.
Cut slates to close the course.
Minimum 6” lap on interlayment joints.