An Explanation of the grades:

Wood is a natural building material. As a result, it will exhibit characteristics that in certain instances will not preform to the function that is intended. Those characteristics would then be considered defects. For example, a cedar shingle that is predominately sapwood does not contain the natural resins for decay resistance in the sapwood portion of the shingle. In the event this particular shingle is used on a roof, the sapwood will rot at a far greater rate than the portion of heartwood that is contained in the shingle. Therefore, while the sapwood may be visually appealing to the eye, it is considered a defect in that it will not perform to meet the expected task. As a result, grading rules for lumber and shingles are developed. A set of grade rules indicate the minimum allowable quality for a given classification.

The Natural Characteristics header refers to the various type of defect that may occur in a given shingle. In reference to those Natural Characteristics, the shingles are categorized into grades. In our case we grade our shingles into four grades. Three are shown here with the fourth being a utility grade.

Wane is a physical run out of the wood in a given shingle. The wood will taper off to nothing in a given spot, usually on an edge. This characteristic is unacceptable in a #1 shingle while a certain degree is acceptable in a #2 or #3 shingle.

Sapwood is the new growth of a tree. It conducts the sap throughout the tree from root to leaf and back again. Sapwood does not contain the resins in a cedar tree that prevent decay like the heartwood contains. Therefore, care must be taken to minimize the amount of sapwood that would appear in a roofing shingle.

Check is an actual physical crack in the shingle. It is acceptable to varying degrees on he tip of a given shingle in relation to its individual width and its intended application. In a #2 shingle that is 8" wide a check that is four inches long, that appears over 10" from the butt of the shingle is still acceptable.

Grain is a reference to the slope the grain appears on in relation to the orientation of the cuts to make the shingle. So; from the butt of a #1 shingle if the grain slopes to one side or another greater than 4" through its length it becomes a #3 shingle regardless if it is the only defect that appears in the shingle.

 

On occasion a tree will become damaged through its life. The damaged area will fill with pitch in order to protect the tree, much like us when we get cut. This damaged area becomes a scar on the tree as well. These pitch pockets and streaks are an undesirable defect in a roofing shingle in that the pitch can wash out and leave a hole or pit in the shingle. If roofing with #2 shingles a considerable degree of this defect is allowable. Care must be taken in the location that a shingle exhibiting these defects is crossed upon. Fortunately however, in my experience, I come across few shingles like this and usually grade them into our utility grade.

Spike knots are knots that appear in an orientation across the width of a shingle. If they extend too far across the shingle, the shingle can leak or break off at the spike knot.

Black knots, loose or rotten knots in a shingle do not hold the water out. When using a #2 shingle where this defect is allowable to a limit, that particular defect is to be treated as a joint and the next proceeding course of shingle must be offset accordingly. Please see our installation instructions for further information in this regard.

Pin knots are knots that are around 1/8" in diameter. They are not as much of a concern as a defect in that they are rarely if ever, loose, encased or rotten.

Tolerances is a reference to the physical milling of the shingle. Ideally, when looking at a shingle from its side, the tip should be 1/8" thick and the butt should be 3/8" thick. However, there are a great degree of variables in the milling process that will cause a deviation from this ideal. Therefore it becomes considered in the classification of the materials.

Widths in the Bundles is a limitation of the amount of narrow shingles that appear in a bundle of a given grade. A shingle that does not exhibit any of the other defects that is 2" wide could be described as a #1 shingle when disregarding its width. However a bundle of such shingles would contain 360 pieces and a square would take 1,440 shingles to cover. It would take two men and a boy a month of Sundays to cover a roof using shingles this narrow. Therefore, the number of narrow shingles that appear in a pack is limited.