2000 by the National Roofing Contractors Association. No

Appendix
SLATE
Evergreen Slate Company, Inc.
On slopes of 8:12 to 4:12, specify 4-in. head laps and
use one layer of W.R. Grace Ice and Water shield for
greater protection.
Evergreen Slate royal purple slate holds its color
very well.
Penn Big Bed Slate Co., Inc.
Plywood decks are not recommended.
Rising & Nelson Slate Co., Inc.
Roofing slate is also available in lengths of 26 through
48 inches in thickness of ½, ¾, and 1 inch.
On slopes of less than 5:12, a 4 inch headlap
should be considered.
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