Cedar Posts and Beams: What to Specify Before Ordering

A request for “some cedar posts, beams and timbers” leaves several decisions unresolved. The supplier still needs to know the cross-section, length, surface, grade, moisture condition, heart-centre preference and which faces will be prominent. For structural work, the engineer’s specification must also identify the grading requirements that support the design.

The core order specification: State the species, member role, actual or nominal size, surface, grade, moisture condition, lengths and quantities. Add boxed-heart or FOHC preference and exposed-face requirements where appearance matters.

Posts, beams and timbers describe shape and use

Industry classifications use a member’s proportions to distinguish posts and timbers from beams and stringers. The label helps organize an order, but the approved design—not the product name—must establish the required size, grade and connections.

Those definitions help organize a specification, but they do not size a structure. Span, loading, connections, notches, holes, exposure and local code determine what the design requires.

Start with actual dimensions, not only the nominal name

The Western Red Cedar timber size table shows why actual dimensions belong on the order. A nominal 6-inch timber can be full-sawn at 6 inches, rough at a typical 5-3/4 inches or dressed at 5-1/2 inches. A nominal 8 is listed at 7-3/4 inches rough and 7-1/2 inches dressed; a nominal 10 is 9-3/4 inches rough and 9-1/2 inches dressed.

• 6 in. — WRCLA rough size: 5-3/4 in.; WRCLA dressed size: 5-1/2 in.

• 8 in. — WRCLA rough size: 7-3/4 in.; WRCLA dressed size: 7-1/2 in.

• 10 in. — WRCLA rough size: 9-3/4 in.; WRCLA dressed size: 9-1/2 in.

• 12 in. — WRCLA rough size: 11-3/4 in.; WRCLA dressed size: 11-1/2 in.

Full-sawn timbers match the nominal dimension. Our rough-sawn 6x6 is listed as a true 6 x 6 inches, plus or minus 1/8 inch, while our dressed 6x6 is listed at 5-1/2 x 5-1/2 inches. Write the required actual size on connection and shop drawings so the member, hardware and joinery are coordinated.

Example line item: 4 Western Red Cedar posts; required actual size: 6 x 6 inches; rough-sawn; appearance: Appearance Knotty; structural grade: per engineer’s specification; green; boxed-heart; 12 feet long; all four faces visible.

Separate appearance grade from structural grade

Clear cedar is selected when limited natural characteristics and a refined appearance are priorities. Appearance Knotty provides a rustic look and good value, but WRCLA notes that its basic appearance classification is non-structural unless structural grading is requested.

No. 2 and Better Structural includes pieces evaluated for strength, while Standard Beams, Posts and Timbers is described as a general-construction grade with no structural values assigned. If a member carries load, the responsible professional must specify the structural grade and applicable grading-rule paragraph—not just “nice knotty cedar.”

Rough, rougher-headed or dressed

Surface affects appearance, final dimensions and finishing. Use our rough-sawn versus dressed cedar guide to compare the surface terms, then state the selected surface and any full-sawn requirement on the order. When only one or two faces are prominent, identify them.

Identifying the prominent faces helps the supplier understand orientation and appearance expectations rather than sorting every face to the same standard. Larger dressed sizes may require a special order.

Boxed-heart and FOHC are cut descriptions

We offer timbers in boxed-heart and FOHC options. Boxed-heart timber includes the tree’s heart centre within the cross-section. FOHC means free of heart centre: the member is cut so the pith is outside the section.

The choice can influence appearance and how checking is expressed as a large green timber dries, but it is not a substitute for grade, moisture or engineering requirements. If checking, exposed faces or joinery are sensitive design issues, state the preference and discuss realistic expectations before ordering.

Moisture condition and checking belong in the conversation

Large Western Red Cedar timbers are commonly supplied green or unseasoned. As a timber dries, some checking and dimensional movement are normal characteristics of solid wood. State whether green, air-dried or another moisture condition is required because changes in section and length can affect joinery, hardware fit and finish timing.

Build the cut list around fabrication

Order length should reflect bearing, end cuts, joinery and site handling. Identify members that must arrive long for field fitting and members that can be ordered to a finished length. If the shop will cut mortises, tenons, housings or bolt holes, coordinate those details with the actual size and expected moisture condition.

• Western Red Cedar species

• Member role: post, beam, rafter, brace or decorative timber

• Nominal and required actual cross-section

• Full-sawn, rough, rougher-headed or S4S surface

• Appearance grade and structural grade, where required

• Applicable grading rule or engineer’s specification

• Green, air-dried or other moisture condition

• Boxed-heart or FOHC preference

• Length, quantity, cut allowance and visible faces

• Connection hardware and fabrication responsibility

• Delivery access, unloading plan and timing

Send us a quote-ready specification

We carry rough and dressed Western Red Cedar posts, beams and timbers, including boxed-heart and FOHC options, for retail and bulk orders. Availability varies by size and order, so send the cut list early—especially for large or long members.

When the drawings and cut list are ready, request a quote.

Three common questions

Can Appearance Knotty timber be structural?

It can be requested with structural grading, but the appearance name by itself is not a structural specification. State the engineer’s required grade and grading rule on the order.

Does FOHC mean the timber will not check?

No. FOHC identifies a cut that excludes the pith. Solid timbers can still check as they dry. Discuss moisture condition, checking expectations and the most visible faces before choosing the cut.

Can the supplier choose the beam size?

The supplier can confirm available products, but the structural designer must establish the member size, grade and connection requirements for the loads and spans in the project.

Important: Before ordering: This article is an ordering guide, not a structural design. Member sizes, grades, connections and modifications must be specified or approved by the responsible building professional.