R & L chooses to utilize high grades of lumber as required by the Wood Truss Council of America (WTCA). We primarily use MSR 1650 Spruce for all of our top and bottom chords and #2 & better for all your web material. When required or requested we also provide the option of using 2400 MSR Southern Yellow Pine (SYP) 2x6 and larger material. R & L require that all of our lumber vendors either ship lumber to us this is either wrapped or tarped to assure that it will not be exposed to inclement weather.