Cedar grading
When you order cedar siding you need to know the grade.
Homeowners and contractors typically order STK for a rustic look and Clear or VG for a modern, clean look, but what do those grades even mean? And are those the only grades available?
What does “grade” mean?
Western cedars are used for “appearance applications” where aesthetics is the primary concern, not structural strength. The primary factors that contribute to the grade are:
The presence or absence of knots. The higher the grade, the fewer the knots and some boards will have almost none. Lower grades of tight-knot material often have knots that are well-scattered and not limited in size.
Grain orientation e.g.: vertical-grain in clear cedar.
Color is NOT a grading factor. Cedar comes in a wide range of colors, from tan to chocolate brown, but the color is NOT a factor in grading. You can’t order “tan cedar” or “chocolate cedar,” units of cedar have a variety of colors, which add to the beauty of this species.
What are the most common grades?
STK, what we call “Select Tight Knot” has tight knots (meaning they won’t pop out) every 3’ or less. It has a lovely rustic appearance with a swirling grain pattern. Technically the STK acronym doesn’t stand for anything, and people use it to mean Select Tight Knot, Sound Tight Knot, Some Tight Knots, See-Through Knots, and even South Texas Knot!
STK Cedar
Clear, or C&Btr, is similar to STK but has a lot fewer tight knots, one every 3-6’. It also has a swirling grain pattern and a cleaner, less rustic appearance.
Clear (C&Btr) Cedar
VG, or Vertical Grain, has almost no knots and the grain runs straight and parallel to the length of the board. It is the most stable grain of cedar. It gives a clean look which works well for modern exteriors, interior ceilings, and soffits.
VG (Vertical Grain) Cedar
But what about A&Btr, Clear Heart, and other grades?
If you’re asking those questions, you’re in the business and know your stuff! Here’s how WWPA (Western Wood Products Association) defines the most common grades used for cedar:
“Select and Finish Grade woods
Select and Finish grades of Western Region woods are widely used for interior walls, siding, architectural woodwork, interior and exterior trim, and hundreds of other standard and special applications…The wide variety of species offers builders and homeowners a rich selection of grain pattern and workability…Western Region species provide excellent surfaces for any kind of finish - natural, stain, or paint.
Grade descriptions for Select and Finish lumber are based on a piece of S4S 1" × 8" × 12' long.
All pieces are graded from the better side or face. The reverse side may be somewhat lower in quality with more restrictions placed on the back of the higher grades.
CLEAR VG HEART
Clear VG Heart Siding is intended for use where the highest quality is indicated. The exposed width, all heartwood and free from imperfections, presents a vertical grain appearance for 3/4 the width from the thick edge. The thick edge may contain slight torn or raised grain.
CLEAR HEART
Clear Heart is recommended for all uses, interior and exterior, where the finest appearance is important. This is the highest grade of Finish, Paneling, and Ceiling produced and many pieces are absolutely clear. Some pieces may exhibit a few minor characteristics which do not detract from their high appearance and quality.
Characteristics and limiting provisions are:
Skip - Very light skips on back
Torn Grain - Light
Warp - Very light
A GRADE – A & BTR
The A grade is also recommended for interior and exterior uses where fine appearance is important. This grade is only slightly less restrictive than Clear Heart. The A grade is ideally suited to applications where finishing requirements are less exacting.
Characteristics and limiting provisions are:
Checks - Small seasoning checks
Knots - Two small, sound, tight knots or equivalent
Skip - Occasional very light skips on edges and back
Torn or Raised Grain - Light
Warp - Very light
CLEAR - C SELECT or C & BTR
Lumber of this grade is recommended for all finishing uses where fine appearance is essential. Because its appearance and usability ranks only slightly less than B & Btr. - 1 & 2 Clear, it is one of the most sought after products from the clear portion of the log. It is widely used for high quality interior trim and cabinet work with natural, stain or enamel finishes.
Characteristics and limiting provisions are:
Checks - Small, well-scattered seasoning checks on the surface
Skip - Light skip on one edge, one medium or two light skips on the back
Stain - Medium stained wood in an occasional piece covering 1/3 the face, or a greater area of lighter stain when not in combination with other characteristics
Torn or Raised Grain - Very light
Wane - On reverse side 1/2 the thickness, 1/8 the width, 1/4 the length in an occasional piece
Cup - Very light
Twist - 7/4 and thinner, 1/2 of very light
8/4 and thicker, 1/4 of very light
Any one of the following characteristics:
Knots - Two small, sound, tight knots
Pitch - Light pitch over not more than 1/2 the face
Pitch Streak - One small pitch streak
Pockets - Two very small pockets
Equivalent characteristics no more damaging than any of the above.”
If you want FREE samples, give us a call at (530) 262-6262, or email us at sales@sidingdirect.com and we’ll ship some samples to you.
Here’s to building beautiful homes!