Sheet Goods Selector

 

Medium-Density Fiberboard, Softwood Plywood, Medium-Density & High Density Overlay Plywood

MEDIUM-DENSITY FIBERBOARD (MDF) Description: Cellulose fibers combined with synthetic resin and formed under heat and pressure. Uses: Excellent for shop jigs and fixtures, cabinets, painted projects, molding and millwork, furniture, and as a substrate under veneer and plastic laminate. Available Sizes: 1/4", 3/8", 1/2", 5/8", 3/4", and 7/8" thicknesses in both 4x8' and 49x97" sheets. Common Grades: One main grade: Industrial. Lower grades, which aren't commonly available, carry "B" or "shop" grade. Also classified by density: Medium-density (MD) is standard; low-density (LD) is a lightweight version. Pros: Flat, no face or core voids, consistent thickness, glues easily, has machinable edges. Cons: Heavy [100 lbs. per sheet in MD grade; low-density version (LD) weighs approximately 60 lbs.], standard wood screws hold poorly. Where to find it: Home centers carry medium-density (MD) 3/4" sheets. Low-density (LD) is available through millwork suppliers and some hardwood retailers. Price (3/4"x4x8', sheet unless noted): $20+ for both MD and LD.

SOFTWOOD PLYWOOD Description: Face-glued layers of thin softwood veneer. Uses: Outdoor projects (exterior rated), carpentry and construction, shop cabinets, substrates, underlayment for floors and countertops. Available Sizes: 1/4", 5/16", 11/32", 1/2", 5/8", 23-32", and 3/4" thicknesses in 4x8' sheets. Common Grades: Veneer grades: A, B, C, D. Panel grades: include sheathing and "Sturd-I-Floor." Exposure: Exterior, Exposure 1, Exposure 2, Interior. Pros: Cheaper than hardwood plywood, readily available, face veneers can have a nice appearance in higher grades. Cons: Built more for performance than appearance; thick plies reduce stiffness; interior plies may have voids, face veneers often patched. Where to find it: All home centers and building-supply stores carry an array of softwood plywood for construction. Price (3/4"x4x8', sheet unless noted): $25+ for A-C sanded, varies by type and material.

MEDIUM-DENSITY & HIGH-DENSITY OVERLAY PLYWOOD (MDO/HDO) Description: Exterior-rated softwood plywood covered on both faces with resin-impregnated fiber (paper). Uses: Used extensively for highway signs, great for outdoor projects, siding, painted projects, watercraft, cabinets, shop fixtures, and concrete forms. Available Sizes: 1/4", 5/16", 3/8", 1/2", 5/8", and 3/4" thicknesses in 4x8' sheets. Common Grades: Follows softwood plywood grading. Face and back plies (which are covered with paper) rate as B grade or better, inner plies are C grade. Pros: Resistant to weather and water, flat, smooth, surface is easily paintable, machines easily, and is very durable. Cons: Not widely available, heavy. Where to find it: Some home centers, wood specialty stores, sign shops. Price (3/4"x4x8', sheet unless noted): $35+ for MDO, HDO costs slightly more.