Solid Sheet, or OSB or Oriented Strand Board, is a nearly 60-year-old manmade wood product. This product was invented in 1963 by Armin Elmendorf, a Californian engineer. It is only now though, with the rise in the cost of other manmade wood-based materials, that OSB has become the wood product of choice for sheds, garden rooms, garden bars, and decking. Read on to explore “What is OSB board?” and the role it plays in various garden building construction areas.
What Is OSB board?
OSB is an engineered wood made from layers of pre-sized wooden strands bonded with adhesives under pressure to create a solid sheet wood product that can be used in place of plywood or particle board. OSB is incredibly versatile and can be used as a water-resistant product, much like Marine Ply (which is a superior water-resistant option), with the added benefit of strength and sustainability.
The way OSB is made lends itself to the construction and insulation of sheds and garden buildings (e.g. garden rooms, summer houses, garden offices, workshops, and even log cabins). The OSB process is a precise engineering process that ensures a robust product that can be used inside and out.
How Is OSB made?
OSB is made by utilising a layered wooden composition, pressed and sealed into place using an adhesive product to produce a timber substitute for modern building practices. While this sounds like a simple process it is complex engineering that means this product is robust and, in many ways, superior to plywood.
Layered composition
The layered composition makes OSB superior to other engineered timber sheets. Here is how the manufacturers make it:
- Small rectangular strips or strands are taken from fast-growing sustainable trees
- These strips are checked for uniformity and dried
- The strands or strips are then coated with waterproof adhesive and cured
The composition and layout of these individual strips make OSB an engineered wood-based product that works so well with modern building practices.
Adhesive and pressing process
The next stage of the process locks in the strength of the wood with the durability of a waterproof adhesive to make solid sheets. This is the next stage:
- The strips, once heat cured, are layered in a specific criss-cross pattern, ensuring each layer sits precisely at right angles to each strand neighbour
- The layered strands are pressed together under intense heat to form solid sheets of usable building material
The strength of OSB vs plywood
The way OSB is made makes it a superior building product for garden structures, sheds, and other buildings. To summarise, you should choose this robust material because of the inherent strength of OSB vs plywood. OSB is layered and sealed, so it maintains strength regardless of weather conditions, making it perfect for shed construction such as shed walls and a shed roof.
Types of OSB for outdoor use
OSB, much like other building products is graded according to its characteristics and suitability for industrial or domestic purposes, here is a rundown on the types of Oriented Strand Board available.
OSB2
OSB2 is an Oriented Strand Board suitable for interior, non-load-bearing purposes. However, you can use it in less exposed garden structures, sheds and buildings. Here are some examples of use for OSB2:
- Interior fit-out in sheds, such as shelves and benches
- Interior shed walls
- Shed or garden building floor insulation
- Shed wall and roof insulation
OSB2 is unsuitable for outdoor building projects and should only be used inside as an insulated building material.
OSB3
OSB3 is the most used building grade designed for load-bearing purposes in humid environments, making it ideal for outdoor projects such as:
- Decking bases
- Exterior storage buildings
- Garden structures like OSB for shed walls
- Log store designs
- Shed bases and shed floors
- Shed roof panels
Oriented Strand Board grade 3 is the perfect all-rounder and is most widely used because of its robust and durable qualities.
OSB4
OSB4 is the ultimate high-durability grade suitable for heavy-duty, load-bearing projects and more exposed outdoor designs, including heavy-duty decking or the structural framework for large garden rooms and garages.
Oriented Strand Board grade 4 is designed for humid, even wet conditions, offering the highest strength and moisture resistance compared to all the other grades. When considering any outdoor project, OSB3 and OSB4 are the most appropriate building materials.
Benefits of using OSB in the garden
OSB is a popular choice for outdoor and garden projects because this man-made timber product offers a wealth of possibilities due to its ability to repel water.
Strength and durability
The secret to OSB’s strength and durability lies within the cross-oriented layered construction, which gives it its unique solidity and shear force resistance, making it ideal for outdoor use. OSB is perfect for the construction of sheds, garden buildings, outdoor structures and decking, designed to withstand the British weather.
Cost-effectiveness
OSB offers a much cheaper alternative to plywood or solid wood. The cost-saving material processing makes it a cost-effective choice for larger outdoor projects such as garages, garden studios or work-from-home offices without compromising on the strength or durability of the product or project.
Weather resistance
Describe how OSB3 and OSB4 are designed to resist moisture, making them suitable for humid or wet outdoor environments such as garden buildings, where they are exposed to rain and dew.
Oriented Strand Board grades 3 and 4 are engineered under pressure with moisture-resistance glues and water-repellent adhesives. The combination of adhesive and the criss-cross-orientated layer system enhances the product's durability and reliance on wet or humid conditions. All these factors make OSB3 and OSB4 ideal for exterior projects because they can endure exposure to rain without compromising structural integrity.
Sustainability
Sustainability is an important factor in the production and saleability of OSB as a solid sheet material. OSB is made from fast-growing, small-diameter trees, and manufacturers often use wood offcuts, making it a more environmentally friendly option than traditional solid timber, Plywood, or particle board for outdoor projects and exterior building design.
OSB in garden structures
OSB has many practical uses as a reliable building material, and it is found in many common garden structures, such as sheds, garden buildings, and garages.
OSB shed roof and OSB for shed walls
Oriented Strand Board is widely used in the construction of shed walls and roofs due to its strength and moisture resistance. This makes the most of its fixed criss-cross-orientated layers to provide structural integrity. This is perfect for use as OSB for shed walls and in an OSB shed roof and can be used in other garden buildings, and garages.
Decking subfloor
Shed and garden building design relies on a subfloor installation to ensure the structure remains weatherproof. OSB is ideal for decking subflooring due to its robust, durable construction and enhanced water-resistant nature. Moisture can rot your decking, and while decking is designed to be an exterior product, the use of OSB subflooring can extend the life of your decking.
Garden room flooring
Oriented Strand Board is a robust choice for garden room and home office flooring due to its strength and stability in wet conditions. The way OSB is made means it is a solid base that can bear significant weight, making it a suitable choice to hold heavy furniture and garden equipment. Additionally, OSB’s moisture-resistant composition ensures it remains stable no matter the humidity levels; all these factors make OSB a reliable and durable flooring solution in any garden building project.
Considerations when using OSB outdoors
Choosing OSB to construct your garden building ensures enhanced weather protection and longevity in any structure that features in your garden or outdoor space.
Protection from moisture
When using an OSB2-grade product as insulation and reinforcement, you must be prepared to use a sealant or paint to prolong the life of the material and enhance its waterproof properties. Grade 2 Oriented Strand Board is a robust material that insulates a shed roof and walls and adds stability. Protecting the OSB from prolonged moisture exposure is key to enhancing your garden building usefulness and longevity.
Edge sealing
There is little doubt that OSB is a versatile product, but even the best waterproof material needs sealed edges. The edge of any sheet material is its weak point and left untreated, edges will be prone to water penetration. Water that gets between the layers will cause swelling and warping in outdoor conditions, no matter how much waterproof adhesive is used in the production process.
Ventilation
Good ventilation is as crucial to the life and useability of your OSB as edge sealing. Proper ventilation is essential to stop moisture build-up. Properly ventilated garden structures maintain a decent level of airflow, which helps maintain the sheet board’s structural integrity, reducing the chance of swelling, warping and degrading even in humid conditions.
OSB vs plywood for garden projects
Before the mainstream introduction of OSB as the mainstay of wooden building products, plywood was widely used in timber-framed garden structures. The change in building trends to more sustainable products has fuelled the move away from more labour-intensive plywood to graded Oriented Strand Board, along with some other factors that make OSB a firm choice for outdoor use.
Cost comparison
OSB tends to be more cost-effective than plywood, making it a popular choice for larger exterior projects where budget is a concern. Here are the key reasons why it is considered a budget-friendly choice:
- Economies of scale - oriented Strand Board is produced in larger quantities, so it benefits from the economy of scale
- Minimal waste - the production of OSB uses nearly all the tree, therefore minimising waste
- Production efficiency - OSB is credited with effective production efficiency involving a highly automated process
- Uniform size - OSB panels benefit from uniformity of size, making them consistent in size and quality
- Wood strands - the materials used in manufacturing use wood strands as opposed to veneer strips
Durability in outdoor environments
While plywood may be more durable in exposed conditions because it dries faster, making it more resistant to swelling, OSB3 and OSB4 offer comparable protection at a lower cost. This makes this solid sheet material suitable for any outdoor project where budget is the primary concern.
Ease of installation
The other major attraction of OSB is that it is easier to install. Because of its uniform composition, this manufactured building material is easier to cut and manipulate than plywood. Plywood’s attraction is its natural wood finish, but the veneer strips require more precision and effort during the installation process.
Common misconceptions about OSB in garden projects
Common misconceptions surround OSB for garden projects, and these are generally unfounded. Here is some detailed information about the useability of the Oriented Strand Board.
OSB cannot handle moisture
Contrary to the myth that the Oriented Strand Board cannot handle moisture, OSB grades 3 and 4 are designed for outdoor use. These grades of OSB use moisture-resistant adhesives that reinforce the cross-layer construction. This creates a sustainable building material specifically designed for outdoor use in the construction of sheds, garages and garden buildings.
OSB is not as strong as plywood
While plywood may have a slight edge in terms of sheer strength, OSB offers ample strength for most garden projects, particularly when used in combination with other protective measures like sealing. OSB is a reliable, cost-effective choice for outside use, utilising its strength, durability, and stability to produce excellent results.
Choosing the right type of OSB for your garden project
While we are great advocates of OSB, you still need to choose the correct grade of solid sheet to ensure your building maintains its highest standards. So, what is OSB board used for, here are some ideas:
OSB for garden sheds
OSB of all grades is the perfect building material for garden sheds due to its moisture resistance and structural integrity, making it ideal for walls and roofing in garden environments. Sheds of all sizes will last longer and maintain their usefulness and purpose over time. So, by using OSB3 or OSB4 for your OSB shed roof or OSB for shed walls, you are enhancing your building’s integrity.
OSB for decking bases
OSB4 is one step up from OSB3 and is perfect for decking bases, where additional strength and load-bearing capacity are needed, particularly in high-traffic areas or larger garden structures. Grade 4 OSB is a heavy-duty load-bearing board and is equally capable of handling humid and even wet environments but with more structural resilience and enhanced strength.
OSB for raised garden beds
OSB3 is the perfect material for building raised garden beds. With proper sealing to ensure that the material can withstand constant exposure to soil and moisture, you can create a garden design that exceeds expectations without blowing the budget.
By choosing the correct grade OSB for your garden scheme, you can relax knowing that a job well done with the best materials is built to last and, more importantly, withstand the elements!
Conclusion
In summary, OSB is versatile and cost-effective for many construction projects especially outdoor ones such as garden sheds and other garden buildings. For OSB shed roof or OSB for shed walls this material provides weather resistance and structural support. The strength of OSB vs plywood is that it is stronger and a great alternative for budget-conscious builders looking for a durable solution. Whether it is for garden buildings or larger outdoor projects, OSB is an essential material for its sustainability and durability. It withstands the elements and maintains structural integrity.
Contact us
The above guide to “What is OSB board?” should be informative. For further advice on topics such as OSB for shed walls and the strength of OSB vs plywood, do not hesitate to contact Buy Fencing Direct in these ways:
- Phone - 0333 003 0515
- E-mails – send emails through the form on our contact page
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