Grading Rules. There is no uniformity as to grades of lumber. Fifteen or more associations have rules for inspection.and classification of lumber and these rules vary with the association and from year to year in the same association. The following rules taken from a catalogue of a middle west lumber concern will be found helpful:
Yellow Pine Dimension, Studding, Joists and Timbers
No. 1 Common. - The best grade and the one recommended for use on first class jobs.
No. 2 Common. - Dimension up to 20 feet long only can be obtained in this grade. Timbers are not manufactured in No. 2. This stock will show defects not found in No. 1 grade, and some pieces are not entirely straight. It is a sound, serviceable grade, but not recommended for first class work.
Yellow Pine Boards, Sheathing, Shiplap, and Fencing No. 1 Common. - This grade is not clear, but is strictly sound and uniform in thickness and width. It is used on the best classes of work, for barn boards, and wherever exposed to wear and weather. No. 2 Common. - This grade is sound but contains more sound knots than No. 1 and is somewhat coarser. It is mostly used on first class jobs for sub or rough floors, and for sheathing under siding. It can be used for outside work, but is not recommended for this purpose except upon cheap buildings. No. 3 Common. - A fairly good lower grade which will work up nicely but with some waste due to cutting out defects. Runs uneven in quality. Makes a fair subfloor or sheathing.
Yellow Pine Flooring, Ceiling, Partition, and Drop Siding
The best grade manufactured. Practically free from defects and the grade used upon first class jobs. Is strong, sound, and will lay without waste due to cutting out of imperfections. Should be used when a natural finish is desired.
No. 1 Common. - This grade will contain small, sound knots, sap stains, pitch or pitch pockets. It is* sound and durable, and a good grade for ordinary work or wherever covered with paint.
No. 2 Common. - Coarser than No. 1 grade; will lay up with little waste. Is sound, and flooring of this grade is often used for sheathing or sub flooring where a warm, tight job is desired. Can also be used on cheap painted jobs.
Fir Boards, Timbers, Drop Siding, Ceiling and Flooring Select No. 1 Barn Boards. - This grade is especially selected and is better than No. 1. No. 1 Timbers. - Good sound straight stock, to be used for sills and posts subjected to moisture. Clear Ceiling. - Free from defects. Good for cornice work and porch ceilings. Edge Grain Flooring, Clear Grade. - Especially suited to porch floors as it wears well and resists effects of moisture. Clear Drop Siding. - Contains no sap, shakes or other defects.
Shingles, Lap Siding, Y. P. and Cypress Finish, White Pine Boards
The heaviest grade - five shingles laid one on top of the other will measure 2" at the butts.
A lighter grade, but clear and 16", as are the 5 to 2 " grade.
Carried in stock in red cedar, redwood, cypress, and white pine. "Clear" is free from all defects.
Cypress " C" Grade. - Has small sound knots and other slight defects such as can be covered with paint. All siding is bundled 10 pieces to the bunch in random lengths. Not furnished in specified lengths.
This stock in "clear" grade is practically free from defects. The yellow pine is suitable for interior finish. Cypress is suitable for inside finish or for cornice work on first class jobs. "C" cypress finish contains some knots and other slight defects. Is suitable for outside finish on ordinary jobs.
As a rule, carried in stock only in No. 1 grade. Nothing but sound, red-knotted boards should be included. No shakes. Excellent for exposure to weather.