Q When I’m installing prestained cedar sidewall shingles, what is the best method to keep the shingles aligned? Is there a way to use a ledger board without marring the surface?

A Chris Yerkes, a cedar-shingle installer certified by the Cedar Shake and Shingle Bureau (CSSB), and owner of Cedarworks, in Brewster, Mass., responds: I always use a ledger board to keep the shingles in line as they are fastened, but how you attach the ledger is critical to protecting the shingle surface. Many installers attach the ledger by simply driving nails through the board and into the face of the course below. This strategy leaves tiny, unsightly holes in each course, however, and those holes can actually cause shingles to crack. So instead of nailing through the shingles, I have worked out a different method to protect the stained surface of the shingles.

The first thing I do for each shingle course, before I attach the ledger board, is snap a chalk line in nonpermanent chalk. This line helps to ensure that the ledger stays perfectly straight.

For the ledger itself, I choose the straightest piece of 1-by lumber that I can find. Some folks just use 1x2 furring strips, but these can be a little flimsy, so I prefer to use a 1x4. The ledger should also be as long as possible for a given wall. You can always add a shorter piece at one end if needed.

Then I attach short pieces of light-gauge-aluminum flashing to the back of the ledger (the side facing the house) using the staples that I use for installing the shingles (nails also work). I space the flashing pieces every 6 to 8 feet along the length of the ledger and bend over the ends of the fasteners where they come through the outer face of the board.

Now I line up the ledger on the chalk line and drive a nail or a staple that bridges the top of each flashing piece.

One nail or a single leg of a staple is enough to hold the ledger while I fasten the shingles, and it easily tears through the light-gauge aluminum when I tap down on the ledger to remove it after the course is installed.

This method leaves no unsightly holes, but the metal flashing can leave “pot marks” on the shingles. I solve that problem by covering the aluminum flashing with thin flashing tape. I keep a roll of flashing tape on hand, but the stuff seems to be on every jobsite these days anyway. The tape covers the flashing below the top edge of the ledger. Then I let it wrap around the bottom of the flashing and onto the lower edge of the ledger. Just be sure to replace the tape when it begins to wear through.