Scoring prevents the wood from chipping when you cut it with a handsaw cut the new piece of siding on the waste side of the line.
How to match old style wood siding.
Take the sample piece of siding to your local home or siding store.
Add an inch to the face width to account for the overlap of the piece above.
For more information on vapor retarders see section 5.
Otherwise you will always be chasing trying to immediately match the existing as other pieces of siding degrade in the future.
Painting sounds like an option but in this case we re talking about painting old wood some of which is reaching the end of its lifecycle.
Show the clerk the piece of siding and tell her the brand and manufacturer.
She can put your sample side by side to stock siding to get you a matching piece.
With the vertical cove cut milled the final step was to cut a rabbet on the bottom inside edge of each board.
Conditioned spaces will require insulation sheathing and house wrap.
The clapboard you use for a patch should blend in seamlessly with your existing siding.
Measure the butt edge thickness and the widths of the exposed faces of a few courses on the wall.
Beveled cedar siding can be installed over sheathing with a vapor retarder such as tyvek or asphalt saturated felt.
If you want everything to match replace everything.
Bringing a length of old siding with you to the lumber yard is the best way to match grains and styles.
This can easily be done with a rabbet kit for a router.
Line up the ends and using the old piece as a guide mark the new clapboard with a utility knife.
Score the cut line with the utility knife guided by a square.