How can the safety and durability of wooden play structures be ensured?

Western Wood Products Association (WWPA) has provided procedures for the quality control of specific gravity of MSR lumber grades at mills since 1996. Jun 17, 2024 ... (2) Approximately 44% of the trembling aspen lumber met the 1450f-1.3E grade for MSR lumber, and 62% qualified for the 1200f-1.2E grade. (3) ... MSR Lumber Producers Council ... Established in 1987, the MSR Lumber Producers Council (MSRLPC) represents the interests of machine stress rated lumber producers ... The solid engineered lumber flange I-Joist is made from 2×3 and 2×4 MSR lumber. FinnForest MasterPlank Laminated Beams and Headers Superior strength and ... Jan 30, 2022 ... MSR lumber is softwood dimensional lumber assigned to various classes based on its bending strength and modulus of elasticity. Spruce Pine Fir (SPF) & Machine Stressed Rated (MSR) Lumber. You Are Here: ... Using only high grade logs of Spruce Pine and Fir, National's SPF timber is an ... It seems likely that the trend toward MSR grading of lumber will also apply to hardwood structural lumber. The basis for the use of MSR lumber is the ... Mar 10, 2025 ... The lumber is graded on its stiffness (1650f, 2100f or 2400f). The grading is the bending pounds per square inch (psi) the lumber can withstand. MSR lumber is also required to meet certain visual grading requirements. The grade mark can include “1W” or “2W” if visually graded to the wane restrictions for ... Machine Stress Rated lumber (MSR) is evaluated by mechanical stress rating equipment. MSR lumber differs from visually graded lumber in that each piece is ...