Tongue & Groove Redwood Siding … This includes redwood tongue & groove siding, plain bevel siding, rabbeted bevel … Redwood Grades, 1/2×4, 1/2×6, 1/2×8.. Tongue and groove interlocked to prevent breakage. TECHNICAL SPECIFICATIONS: SPECIES SIZE. LENGTH PATTERN. KD SPF. 2×6 2×8. 8 20′.. The builder is suggesting we use 2×8 tongue-and-groove boards for both the […]