Green lumber dimensions for thickness and width are closer to the nominal dimensions than the dry lumber dimensions. Timbers are generally surfaced while still green. Nominal thickness ranging from 2 inches up to, but not including, 5 inchesĥ or more inches in nominal thickness in the least dimensionĭimension lumber and boards may be surfaced green or dry, depending on the manufacturer.
Lumber may be categorized according to thickness as follows: Boards Width ranges from 2 to 16 inches nominally. The stated length equals the actual length, unlike width and thickness which are typically given in “nominal” dimensions that are somewhat larger than actual dimensions. Softwood construction lumber is generally machined to lengths that are multiples of 2 feet. Standard Dimensions of Softwood Construction Lumber
The 1.00″ is a minimum and not the actual. Similarly, for green or air-dried 4/4, the grading standard is 1.00″, but most hardwoods are 1/16″ to 1/8″ thicker on the average. There is no industry wide standard for ACTUAL surfaced thickness. For example, for 4/4 dried and surfaced there is a lot of 15/16″ hardwood (and also a lot of 3/4″ which is under). In reality, the ACTUAL thickness of planed lumber is generally not 3/16″ under the nominal for 6/4 and less and under 1/4″ for thicker, but will actually be a bit thicker. That is, what the grader uses for judging the grade of the lumber. The S2S values represent grading standard thickness. Note that the S1S thicknesses are not standard – the actual thickness is typically subject to contract agreement. The S1F and S2F thicknesses are for dried lumber. This convention is not normally used for softwood lumber although softwood decking is often marketed as 5/4 thick. 4/4 refers to a 1 inch thick board, 6/4 is 1-1/2 inch, 8/4 is 2 inches, and so on. in the following thicknesses: Rough DimensionĪ “quarter” system is commonly used in the hardwood lumber industry when referring to thickness. Hardwood lumber is generally sold in the U. Although standard widths are not established, the hardwood lumber grades do specify minimum widths for each grade as follows: FAS, F1F There is, however, some level of standardization in that boards are cut to standard lengths of 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, and 16 feet. Because of their higher cost and scarcity relative to softwoods, hardwoods are often cut to whatever widths and lengths are most convenient and cost-effective.