There is a grade of Redwood for almost any application suitable for wood.
ARCHITECTURAL GRADES:
Architectural grades of redwood should be specified where the visibility and design integrity call for the material to maintain its appearance long beyond the initial application. These quality redwood grades are available Air seasoned, Kiln Dried, or unseasoned. Unequaled in beauty and stability, they are the best choice for precision joined and intricate or formal architectural designs.
Clear All Heart
Finest architectural heartwood grade. Available in Kiln Dried, Air Seasoned or Unseasoned .this grade is well manufactured, free of defects on one face, and is the highest of the Redwood grades. The reverse side might have slight imperfections. Available surfaced or saw-textured. This grade is used for siding, paneling, trim, molding fascia and millwork. Also fine for decks and garden structures.
Clear
Similar quality to Clear All Heart except containing various amounts of sapwood (white color wood). This grade is ideal for highly visible, above-ground applications. Available in Kiln Dried, Air Seasoned or Unseasoned.
Heart B
It contains limited knots and characteristics not permitted in clear grades. Uses similar to Clear All Heart.
B Grade
Similar characteristics as B Heart but containing sapwood. Same uses as Clear. This is a quality grade containing sapwood, limited knots and other characteristics not permitted in Clear All Heart or Clear. This is used for quality decking, garden shelters, and other above-ground outdoor applications.
GARDEN GRADES:
These economical grades of redwood are tailor-made for outdoor applications. The varied wood grains and knot-textured surfaces blend well with other natural materials. Garden grades are available seasoned or unseasoned and are surfaced on four sides (S4S) or rough sawn. They are available in dimensions from timbers 20-feet in length to bender board, used for edging garden walkways.
Construction Heart
All common heartwood grades contain knots. They are recommended for work on or near the ground such as posts, beams, joists, and decking. Construction Heart is available in rough or Surfaced forms.
Construction Common
It contains knots and a combination of heartwood and sapwood. It is recommended for above ground applications such as railings, fence boards, benches, and decking.
Merchantable Heart
Most economical all-heartwood grade allows slightly larger knots than construction grades with holes limited to the size of knots. Allows checks, some splits, and some manufacturing flaws. Used for retaining walls and garden or utility structures on or near the ground.
Merchantable
Same characteristics as Merchantable Heart but containing sapwood. Suitable for fence boards, trellises and above ground garden and utility applications.