This plywood is chemically treated with a fire retardant, making it less likely for the plywood to catch fire. The threshold for this is about four months. The thickness of plywood normally used is 1/8″, 1/4″, 1/2″, and 3/4″. Our plywood calculator can estimate the number of 4′ x 8′ sheets needed for a project. Fire Retardant Treated Plywood: 1/2", 5/8", 3/4". Solid, more knots than A grade, possible minor splits. Commonly square edge, but may be produced with tongue and groove edges. Available in 3/8″, 1/2″, 5/8″ and 3/4″ thicknesses. Unplugged knots and knotholes up to 3 inches, splits and other defects allowed. Both types of panels swell around the edges as they get wet, but plywood returns nearly to its original thickness as it dries, while OSB swelling is irreversible. These clips, so named due to their shape, connect the edges of adjacent sheets of plywood, halfway between the rafters, helping to ensure that one panel doesn’t bow one way and the next bow the other way. The nominal thicknesses of plywood range from 1/8 inch, or 3.2 mm, to 1 1/4 inches, which is equivalent to 31.75 mm. They grow quicker than hardwoods, which have leaves that they lose every fall. 2440 mm. Exterior sheathing is most often ½” thick (nominal dimension; actually 15/32” measured dimension) for both walls and roofs. These often aren't the actual thicknesses, however, because sanding during manufacturing removes up to 1/32 inch of material. Minimum Plywood Thickness The International Residential Code specifies 3/8-inch plywood for sheathing walls with a standard stud spacing … The point where the H-clips are, will not have any spacing, but the two sheets of CDX plywood will be butted up against each other. Plywood Alternatives. This type of plywood won’t sag when used on a 12 inches joist structure. While this may not be allowed by building inspectors in all jurisdictions, it is in many. CDX stands for class C to D exposed plywood. The good news is that CDX plywood is available at most home and garden stores, since it is a common material used for home DIY and construction projects. CDX plywood is often utilized as roof sheathing or for exterior walls due to its water resistance. From . While this process does not produce attractive grain patterns, the larger veneer sheets make it much easier for construction plywood out of. This additional strength really helps when using CDX plywood as subfloors. The weight of a panel will vary by thickness and the type. Exterior grade plywood, marked with an “X” after the surface grade (CDX plywood means face side is grade C, back side is grade D, and the plywood is intended for exterior use) uses a resin that is more water resistant than interior grade plywood. of Plies in a Plywood. Even within the exterior classification we can find differences, based upon the rosin used to bond the veneers together. CDX Plywood has a C grade front side, D grade back side, and exterior glue. The thicker the plywood, the more noticeable depth the gap is between the planks. Find the room's perimeter to find out how much trim is needed. Even ¾” thick plywood cannot cover a broad span, supporting weight, without sagging. It is rot resistant with knots replaced with football shaped plugs to give it a smooth moisture-resistant surface. Although considered an exterior plywood, CDX is often utilized as the subfloor for kitchens and bathrooms— especially for floors destined to be finished with ceramic tiles. Plywood is generally available in 4’x8′ sheet and is cut into a square board. Most plywood underlayment is about 1/4 inch thick and has square edges and a smooth, knot-free top face. Actual Thickness. Get the latest news, tips, tools and product updates for all your roofing projects. While the length and width are often the actual dimensions, the nominal thickness is usually different than the actual thickness. It is not necessary to fill the splits or knotholes in the face veneer of CDX plywood, when used as a substrate for ceramic tile. Feet and Inches Length Measurement Calculator. CDX Plywood Size, Thickness, and Availability. 0.563 inch. Limited number of patches. Board footage is a measure of the volume of wood in the sheet. Learn how to layout wainscoting with all panels a consistent size for an even look. This grade of plywood has many voids in it. The letters “CDX” refer to the grade of plywood panel. First, wood shrinks as it dries and moisture leaves the wood. The designation of being exterior grade plywood can also mean “Exposure grade 1” which stands for damp-proof plywood used for demanding environments such as underlayments and roof sheeting. Radiant Barrier aluminum backed sheathing -- Improves energy efficiency. For example, a groove for the base in a cabinet needs to be the exact thickness of the plywood or the cabinet will not be stable due to the loose fit of the parts. Show more. Moisture resistance • Plywood absorbs water faster and dries out faster than OSB. Job-site handling • OSB panels lie flat and are engineered for consistent C and D grade plywood veneers aren’t smooth and don’t have an attractive grain pattern, so they wouldn’t be used for furniture or commercial fixtures where the grain is visible, unless the intent is to provide an industrial appearance. FSC Certified plywood for green construction. CDX is a great economical choice for construction grade plywood! The only exception is plywood which is stated as “having no voids,” such as marine grade plywood. 3/4” plywood by its more accurate thickness of 23/32”, 5/8” plywood by its more accurate thickness of 19/32”, 1/2” plywood by its more accurate thickness of 15/32”, 3/8” thick plywood by its more accurate thickness of 11/32”. But that’s four months of normal rainy weather, not four months of snow and ice buildup. Allow the filler to dry and then sand, before applying the flooring. Smooth, paintable surface. Most plywood, other than hardwood cabinet grade plywood, is graded with two letters, showing the face and reverse side grading of the plywood. As its name implies, the splits and defects have been plugged. Rated sheathing, also known as CDX in the trade; ... (Panel width and length may vary up to 1/8" to aid with proper installation) Specifications. When it comes to choosing a subfloor for a ceramic tile floor it is always best to choose CDX plywood over OSB— it’s stronger and doesn’t have the problems with moisture that OSB does. Marine grade plywood also has better face veneers than CDX, which are sanded smooth. Softwood plywood, which includes CDX plywood, is either made of pine or fir. Otherwise, it will absorb water, with all the ensuing problems. Some mistakenly think the "X" stands for "exterior"—which is not true, exactly. This support keeps the shelf from sagging. Actually, the odd number of veneer layers allow for an even number of glue layers. Sheets are available in hardwood or softwood veneers, and in varying grades including sanded and unsanded. CDX Plywood Thickness Availability. When CDX plywood is used as roof sheathing, the C side of the plywood is placed up, where it will be covered by roofing felt and then shingles. Get results in imperial and metric measurements. Add and subtract feet, inches, fractions, centimeters, and millimeters with ease.