what is double coursing
Double up. Another method of installing cedar shakes is double coursing. This method makes use of an undercourse shingle placed on top of the preceding line of shingles. This makes for a more economical installation since a lesser-grade product is used for the undercourse. Double coursing produces a more defined scale appearance than that of shakes installed using the single coursing method. What nails are best? The type of nails you choose to use when installing cedar shake siding should be considered also.