Cedar planks were a primary part of building in the Fraser Valley and the greater Northwest Coast. The shed-roof houses of the Coast Salish relied heavily on the production and maintenance of cedar planks. Planks were produced, and often stockpiled, to add on to the longhouses when arrivals were expected from extended families.
Planks were produced through the use of wedges and a hammer to separate the wood planks from the larger trunk along the grain of the tree. The most controlled variation of this method involved chiseling out grooves on either side of the plank-to-be, and then driving wedges into the grooves to begin removing the plank from the log or tree. Once the plank began to separate from the log, a pole was inserted horizontally between the plank and the log. As the wedging and hammering advanced the removal of the plank further down the log, this pole was advanced to keep the plank under tension. The pole could also be used to pry the plank off the log. This technique could be repeated to produce multiple planks from the same log.
Many of the planks did not require any further processing, other than some minor finishing to the surface. On the other hand, some of the planks might have had knots or a wood grain that was not straight. Several methods were used to reduce or eliminate these problems. The most basic method involved placing the warped board onto a straight board and laying very heavy rocks onto the areas of the warped board that required straightening. Another method involved 'sandwiching' warped planks between straight planks and binding them tightly together to force any warped features out of the wood.
The creation of a smooth surface on the wood plank was important to the design of carvings or painted objects. The wood was typically primed for use by smoothing the surface with a flat sandstone rock, to which sand was added in order to increase the grit. The finish could be further refined by rubbing dogfish skin on the surface.
The durability and versatility of cedar made it an important resource to the Stó:lō people, who used it for more than just planks and carvings. The ability to steam and bend cedar with little difficulty made it an excellent raw material to produce cedar boxes, children's cradles, and drums.