Granville
Manufacturing
Company
QUARTERSAWN CLAPBOARDS
Quartersawn, "vertical grain" clapboards are the best investmentyou can make for your home. This highly stable product is always recommendedfor applications with extreme weather exposure, or for surfaces which takeabuse. This milling procedure leaves a straight, vertical grain which minimizes cupping, warping and twisting. Quartersawing exposes the maximum numberof grain surfaces, which act like capillaries to better absorb paint andstain. The following illustrates the quartersawing process:
Quartersawing Versus Resawing
A log
is rotated and sawn ---------------------------------One
inch boards are sawn from logs
- --into
pie shapedpieces. ----------------------------
-------and
then cut diagonally on a bandsaw.
---------------------
Grain is vertical
to board. ----------------------------Grain
is curved to board.
Leaves a straight vertical grain that resists -----------------Leaves
a curved or horizontal grainthat tends
wood's natural tendency to warp and twist.-----------------to
warp and twist opposite the curve ofthe
------------------- ----------------------------
--------------growth
rings.
Production of Quartersawn Clapboards
Raw Material: Six foot logs of eastern white pine or spruce over13 inches in diameter.
Lathing the Log: To remove bark & even the diameter of thelog.
Before
After
Sawing
the Log:
The log is mounted on a carriage that moves over a saw which makes a cut along its full length. By rotating the log 3/4 " after every cut a tapered clapboard is produced. The process is continued until the logis rotated 360°
Drying the Clapboards: Kiln and air drying of clapboards by alternately layering uniform diameter clapboards into six foot by sixfoot stacks until dried to a 12% moisture content.
Planing and Grading: Clapboards are planed and edged on one side. The ends are squared and clapboards graded as follows:
1 X Clear: Clear unmarked on exposed section of clapboard.
2 X Clear: Up to one knot or blemish on exposed section of clapboard
Rustic: Clapboards are graded on the rough circular sawn side and are essentially clear.
Sizes: -6"
clapboard graded to 4" exposure
----------5 1/2"clapboard
graded to 3 1/2"exposure
----------5" clapboard graded to 3"exposure
----------4 1/2"clapboard
graded to 2 1/2"exposure
6" 
5 1/2"
5"
4 1/2"
--------------------------7/16"
Packaging: Clapboards are sorted by length and grade and strapped into bundles. They are then stacked and palletized. The pallets have bundles of boards varying in length from 2' to 6'. The majority of boards will be longer lengths.