ToughRock Sheathing should be installed per ASTM C1280 and Gypsum Association documents GA-253 and GA-254.
On every Georgia-Pacific sheathing panel you should be able to find an APA grade stamp. This stamp is your assurance that the product is manufactured in accordance with the APA’s rigorous program of quality inspection and testing. The grade stamp on a panel also tells you a lot about the panel – the span rating, exposure rating, panel thickness and the building code approval the panel meets.
OSB can be painted with an oil-based paint. Latex paints are not recommended.
The number of panels in a unit of OSB varies depending on the type and thickness of product. On sheathing products, the piece count is typically stenciled on the side of the unit. Other products have corrugated side protectors that should indicate piece count. If you need a piece count and neither of those are visible, please contact GP at 800-284-5347.
Class III or C
Yes. Use the Negative Wind Load Resistance values as listed in Gypsum Association GA 235. If specific published test values are required, we would recommend using DensGlass® Sheathing or DensElement® Sheathing, which have published negative wind load resistance.
Whenever possible, store panels under a roof. Keep sanded panels and appearance-grade products away from high-traffic areas to prevent damage to surfaces. Use pieces of lumber to weigh down the top panel in a stack to reduce warpage from humidity. If moisture absorption is expected, cut steel bands on bundles to prevent edge damage.
If panels must be stored outside, stack them on a level platform supported by at least three 4x4s to keep them off the ground. Place one 4×4 in the center and the other two 4x4s 12 to 16 inches from the ends. Never leave panels or the platform in direct contact with the ground.
Cover the stack loosely with plastic sheets or tarps. Anchor the covering at the top of the stack, but keep it open and away from the sides and bottom to ensure good ventilation. Tight coverings prevent air circulation and when exposed to sunlight, may promote mold or mildew. (Source: APA Builder Tip U450: Storage and Handling of APA Trademarked Panels)
Air barrier membranes and coatings can be applied to ToughRock Sheathing. See the manufacturer’s recommendations for substrate and job site condition limitations.
The paper facers are made with 100% recycled paper. The total amount of recycled content depends on the manufacturing location. Refer to GP Gypsum Technical Services (1-800-225-6119) for more information.
ToughRock Sheathing incorporates a moisture-resistant core and paper but is not tested specifically for mold resistance. If you require a sheathing product that has been tested in accordance with ASTM D3273, consider using DensGlass® Sheathing or DensElement® Sheathing.
Georgia-Pacific Gypsum does not offer a limited warranty for ToughRock Sheathing for exposure to weather conditions. Per the Gypsum Association publication, GA-253, the product needs to be covered with a weather-resistive barrier within 30 days of installation. If you require a product that does have a limited warranty for exposure to normal weather conditions, consider using DensGlass® Sheathing or DensElement® Sheathing.
OSB is not recommended for outdoor projects. OSB is considered an Exposure 1 panel, which means they may be used for applications where construction delays may be expected prior to providing protection. But OSB is not suitable for long-term exposure to the weather.
According to the Gypsum Association publication GA-216, gypsum board could be applied in a ceiling framed 24″ o.c. provided the board length is at right angles (perpendicular) to the framing members. When a water-based texture is to be applied, the maximum spacing for traditional 1/2″ gypsum board is 16″ o.c.
We always advise our customers to use either 5/8″ board, ToughRock® CD® ceiling board, or 1/2″ ToughRock Lite-Weight in such applications. Once the board sags, it is much more expensive to replace than to use the right product initially. Sag in the ceilings of new homes is a common complaint. Most often, research reveals it is not the board but job site conditions that cause the board to sag. Propane heaters combined with poor ventilation cause build-up of moisture in the house.
Georgia-Pacific does not recommend using ToughRock Sheathing for these applications. Instead, consider using ToughRock® Fireguard C® Soffit Board , DensArmor Plus® Type C, or DensGlass® Sheathing, depending on the fire rated design and are designed for soffit applications.
Structural I refers to certain specialized strength and stiffness characteristics of wood structural panels while the term Exposure 1 refers to the glue bond durability of a wood structural panel. Structural I, also referred to as “STRUC I”, may be OSB or plywood and is, essentially, a subcategory of APA Rated Sheathing. Panels designated Structural I must meet all of the manufacturing and performance standards of Rated Sheathing, as well as certain additional requirements.
The advantages of Structural I Rated Sheathing over standard Rated Sheathing panels of the same Performance Category are realized in certain specialized engineered applications such as engineered shear walls and engineered horizontal diaphragms. Specialized construction situations requiring installation of roof sheathing panels with the strength axis parallel to supporting structure also benefit from the use of Structural I sheathing. Structural I is of no additional benefit for other traditional construction applications. Consult a professional engineer for specific applications.
Within the grade stamp on a panel you will find the span rating. When there are two numbers separated by a slash (i.e. 48/24), the first number is the maximum recommended center-to-center spacing for supports in inches when the panel is used for roof sheathing with the long dimension across supports. The second number is the maximum center-to-center spacing of supports in inches when the panel is used for sub-flooring with the long dimension across supports.
Placement of control joints are determined by the design professional. When they are not designated, the requirement for ceilings and walls is the same. A control joint should be installed every 30 feet when there is not perimeter relief. When there is perimeter relief, control joints can be installed every 50 feet.
The number of veneers/plies in our plywood products depends on thickness of the product. Here are the standard number of veneers/plies for some of our common thicknesses:
¼ – 3-ply
3/8 – 3-ply
11/32 – 3-ply
15/32 – 3-ply OR 4-ply
19/32 – 4-ply OR 5-ply
23/32 – 5-ply
7/8 – 6-ply
The number of panels in a unit of plywood varies depending on the type and thickness of product. On sheathing products, the piece count is typically stenciled on the side of the unit. Other products have corrugated side protectors that should indicate piece count. If you need a piece count and neither of those are visible please contact GP at 800-284-5347.
Exterior panels are suitable for applications subject to long-term exposure to weather or moisture, while panels classified as Exposure 1 are intended to resist the effects of moisture on structural performance as may occur due to construction delays, or other conditions of similar severity. Exposure 1 panels are made with the same exterior adhesives used in Exterior panels. However, because other compositional factors may affect bond performance, only Exterior panels should be used for long-term exposure to weather.
According to the Gypsum Association publication GA-231, gypsum board should not be allowed to get wet; it should be covered if stored outside. However, there are situations where the board could get wet during transportation/storage or when installed in-place. If the board gets wet in an installed in-place situation, first remove the sources of moisture. Lay the board on a flat surface and allow it to dry out thoroughly. Once the board is dry, examine it for paper-to-core bond and mold and mildew growth. If installed, examine for nail pops and sag (in the case of ceilings). Paper-to-core bond failure and board sag are irreversible damage, and the board should be replaced. For nail pops, place a fastener an inch above or below any popped-up nail.
Yes, Georgia-Pacific plywood and OSB panels only use moisture resistant adhesives that contain no added urea formaldehyde resins, and are therefore exempt from U.S. EPA and California formaldehyde regulations due to their very low emission rates.
Plywood panels from Georgia-Pacific are made from wood sourced through a system that is third-party certified to the Sustainable Forestry Initiative® procurement standard.
Whenever possible, store panels under a roof. Keep sanded panels and appearance-grade products away from high-traffic areas to prevent damage to surfaces. Use pieces of lumber to weigh down the top panel in a stack to reduce warpage from humidity. If moisture absorption is expected, cut steel bands on bundles to prevent edge damage.
If panels must be stored outside, stack them on a level platform supported by at least three 4x4s to keep them off the ground. Place one 4×4 in the center and the other two 4x4s 12 to 16 inches from the ends. Never leave panels or the platform in direct contact with the ground.
Cover the stack loosely with plastic sheets or tarps. Anchor the covering at the top of the stack, but keep it open and away from the sides and bottom to ensure good ventilation. Tight coverings prevent air circulation and when exposed to sunlight, may promote mold or mildew. (Source: APA Builder Tip U450: Storage and Handling of APA Trademarked Panels)
Georgia-Pacific has always made a quality 1/2″ paper-faced gypsum board. In the first half of 2015, Georgia-Pacific Gypsum introduced an upgraded 1/2″ paper-faced gypsum board called ToughRock® Fireguard 45™ Gypsum Board. The improved 1/2” board has enhanced fire-resistive properties and can replace standard and lightweight gypsum board in ALL 1/2″ wall and ceiling assemblies, including 24″ o.c. framed ceilings. ToughRock Fireguard 45 Gypsum Board is a standard weight 1/2″ interior wallboard that has achieved a 45-minute UL classified fire rating in select assemblies (consult local codes for actual requirements). For additional information concerning fire ratings and fire safety, go to www.buildgp.com/safetyinfo.
Research used to shape the innovation process considered consumer concerns about home fire safety. Learn more>>
Within the grade stamp on a panel you will find the span rating. When there are two numbers separated by a slash (i.e. 48/24), the first number is the maximum recommended center-to-center spacing for supports in inches when the panel is used for roof sheathing with the long dimension across supports. The second number is the maximum center-to-center spacing of supports in inches when the panel is used for sub-flooring with the long dimension across supports.
Plywood panels classified as “Exterior” are suitable for applications subject to long-term exposure to weather or moisture.
Yes, plywood can be painted using one coat of acrylic latex primer and at least two coats of acrylic latex paint. Oil-based paints are not recommended.
To prevent the introduction and spread of plant pests, ISPM 15: International Standards for Phytosanitary Measures, requires that internationally shipped solid wood pallets be debarked, treated with heat or fumigated with methyl bromide, and marked with a seal of compliance. Pallets made with engineered wood are exempt from ISPM 15 regulations. This is because the process of manufacturing engineered wood destroys any live organisms in the wood. (Source: “Boxes, Crate and Reel Manufacturing,” www.PerformancePanels.com)
On every Georgia-Pacific sheathing panel you should be able to find an APA grade stamp. This stamp is your assurance that the product is manufactured in accordance with the APA’s rigorous program of quality inspection and testing. The grade stamp on a panel also tells you a lot about the panel – the span rating, exposure rating, panel thickness and the building code approval the panel meets.
Class III or C
While gypsum boards are stronger in one direction, they may be installed either vertically or horizontally on both wood and steel studs. If the boards are to be used in a fire rated assembly, then use the board orientation that is stated in your specific rated assembly.
No, span ratings for similar thicknesses are the same.
