Clear face in a log

Clear face, cat face and trim, defined. March 4, 2002

What do the terms "clear face" and "trim" mean, in regard to logs?

Forum Responses
West of the Rocky Mountains, "clear face" means a log that is free of knots or any other telltale signs of defects, such a "cat faces", deep scars, bumps (because of previous limbs or scars). "Trim" means, for example, that the log is 16' 10". The ten inches represents the trim. For Douglas fir logs, the requirement from the mills around here is at least 10" of trim. The trim is said to be figured into the Scribner Scale system by which they are scaled. However, I sometimes find that difficult to handle.

Clear face has no knots, limbs, bumps, cat faces or other defects.

In the northeast, trim is 6" on softwoods and 4" on hardwoods, usually. Could someone please give a definition of cat face?

From contributor G:
The National Forest Log Scaling Handbook just says "scars or wounds, often caused by falling objects scraping against a tree." They are not considered a defect if they can be removed with the slab, but caution to watch for pitch, wormholes, and rot. If ants are present there could be deeper rot present.

If you look at a log, picture it as having 4 sides (square). If it is one side clear, then one of the sides of the square won't have any defects, such as knots. A cat face is a knot in the log or tree. You can see this by looking closely at the bark. It is usually a circle or swirl in the bark. Sometimes knots will stick out with a big lump where a large limb once grew. Cat faces are smaller knots that do not bulge out in the log but are hidden within.

A cat face is generally where another tree has skinned the tree while standing, either by nature or careless logging. Usually the bark is missing.

From contributor G:
A knot is a defect regardless if it was overgrown and looked like a bump or if it partially healed and looked like a cat face and would not be allowed in a clear face.

In log grading terms, to call a knot a cat face is not accurate since it is already a defect. A cat face is thus a break in the bark (not including a knot), which, if it can be removed with the slab, could be included in a clear face.

When grading a log's face (hardwood log), a "clear face" could be one that satisfies the grading rules for a No.1 log, which means that it will be at least 10/12 clear in length and fully clear from edge to edge of the face. It does not have to be 100% clear from end to end, as the FAS lumber grading rules do not require a clear piece of lumber, but one that is 10/12 clear or more.

Gene Wengert, forum technical advisor

Contributor G, when cruising timber, a cat face seen on a tree must be considered a knot. If you think taking a slab off will remove the knot, you will lose money when bidding on timber. From what I've seen, cat faces are deep knots in the logs. The swirl or cat face you see is from the wood and bark growing over top of the knot. If a tree fell and scarred another, you would not get a cat face or a swirl in the bark. You get a long lump or irregular pattern in the bark from the tree running down the side as it was falling. In scaling a log, anything shown on the outside must be considered a defect.

From contributor G:
I certainly agree that a knot is a defect and that the bark may be partially or fully overgrown and look like a cat face, but irregardless of the surface appearance, it is called a knot and not a cat face. The defect called cat face is defined in the log scaling handbook as "scars or wounds, often caused by falling objects".

The cat faces that I've seen were pretty much round, didn't appear to be skinned or scarred, but may have been bumped, but always covered with bark. Cat face may be defined as a wound but is often a knot which is put in #2 log when possible.