Minimum: 7/16” thickness. (Exception: 3/8” for gable end walls structural sheathing.)
Exterior plywood sheathing should generally be at least 1/2 inch thick, although 5/8 inch is often recommended for added strength and insulation.
Strength. OSB and plywood are very similar in terms of strength, but plywood is stiffer than OSB by a factor of approximately 10%.
Greater distances and loads require thicker boards. In the case of ceilings, boards between 18mm and 25mm thick usually deliver good results. Tables to aid in properly dimensioning SWISS KRONO OSB products are available on our website.
The weights of osb and plywood are similar: 7/16-inch osb and 1/2-inch plywood weigh in at 46 and 48 pounds. However, 3/4-inch Sturd-I-Floor plywood weighs 70 pounds, 10 pounds less than its osb counterpart. Even the storage recommendations are the same: keep panels off of the ground and protected from weather.
Wood frame exterior walls must be fully sheathed, including areas above or below wall openings, with minimum 7/16-in. wood structural panels.
OSB can be manufactured into panels that are larger than plywood. OSB is more uniform, so there are fewer soft spots, such as those that can occur in plywood. OSB is less expensive than plywood. To build a typical 2,400-square foot home, OSB may cost $700 less than plywood.
Structural sheathing shall be installed in accordance with Figure R603. 9 and this section on all sheathable exterior wall surfaces, including areas above and below openings. Structural sheathing panels shall consist of minimum 7/16-inch-thick (11 mm) oriented strand board or 15/32-inch-thick (12 mm) plywood.
Disadvantages of OSB
Not moisture proof - OSB should be kept dry and does not perform well with prolonged wetting. It can swell, warp and lose strength if left unprotected. Weaker across the width - OSB has less stiffness across the panel compared to plywood. Additional bracing may be needed for some applications.
The smooth side has a better moisture resistance and will ultimately provide better performance against weather. Facing the board smooth side out will maximize its ability to keep moisture out of the structure. It is simple why manufacturers create roughness on OSB boards.
Plywood weighs less than OSB. Nails, screws, and fasteners are more likely to remain more firmly in place with plywood than OSB. Plywood panels swell less than OSB when they come in contact with moisture. Swollen plywood will also usually return to its nominal thickness when it dries out.
Choose a sealant compatible with OSB and suitable for your project's needs. Apply the sealant using a caulking gun, focusing on the edges and any joints between panels. Use a putty knife or your finger (wearing a glove) to smooth the sealant and ensure complete coverage.
Prone to swelling edges and telegraphing.
“The major disadvantage of OSB is that if it gets exposed to significant amounts of water or moisture, the edges expand by up to 15% ... especially if they are cut edges. This swell will then telegraph onto the shingles or some flooring," according to PATH.
Nails are a popular selection for roofing, siding and sheathing projects. The amount of fasteners that are needed in these projects makes nails a more attractive choice because they offer a lower price point.
2021 International Building Code (IBC) - CHAPTER 23 WOOD - 2304.6 Exterior wall sheathing.
Strong Lifespan: The lifespans of engineered woods can often be a key drawback, but OSB panels boast a longer lifespan, offering 30 to 60 years of dependable performance. This further makes them a cost-effective choice, as they will not need to be replaced as often.
Like CDX plywood, solid wood sheathing planks also provide a very strong fastening surface and hold nails/screws better than OSB. Another benefit of diagonal tongue-and-groove sheathing is that the boards are much easier for smaller construction teams to work with compared to large OSB panels.
Formaldehyde is a volatile organic compound that can cause respiratory problems and other health issues, so using OSB instead of materials with higher levels of formaldehyde can contribute to a safer indoor environment.
The standard nailing pattern for sheathing depends on the type of sheathing material and the local building codes. However, a common nailing pattern for wood structural panels (plywood or OSB) is to place nails every 6 inches along panel edges and every 12 inches along intermediate supports (studs, joists, rafters).
Ideally we'd have no vapor barrier in summer; but short of that we should at least have one that allows as much drying to the interior as possible without sacrificing its winter performance. So the closer your vapour barrier is to 60NG, the better.
Oriented Strand Board
For OSB, a voluntary colour coding system exists that consists of 2 colours; the first colour is either white or yellow. White shows that the board is for general purpose and yellow that the board is for load bearing. The second colour is either blue or green.
Environmental Impact: OSB's manufacturing process utilises smaller, fast-growing trees, which could be considered more sustainable. Ease of Installation: Both materials are relatively easy to install, with plywood being slightly more forgiving due to its ability to hold screws along the edges better.
Yes, 9mm OSB (Oriented Strand Board) is suitable for shed walls. OSB is a strong and durable sheet material commonly used in construction projects, including shed walls. It provides good structural integrity and is cost-effective.
Here are some options to consider: Liquid-Applied Membranes: Liquid waterproofing membranes, such as polyurethane or acrylic coatings, provide a seamless and flexible barrier against water intrusion. These products can be rolled or sprayed onto the OSB board and create a durable protective layer.