Story at a glance:
- Oriented strand board (OSB) is an engineered wood material often used as sheathing.
- The high cost of OSB and its moisture susceptibility might make other solutions more attractive to builders and architects.
- An OSB alternative like fiberboard, rigid foam insulation, or fiberglass-faced gypsum board come with varying benefits.
Oriented strand board (OSB) is commonly used in projects as a sheathing material for walls, roofs, and subfloors. But rising demand and steadily increasing prices mean builders and architects may want to consider an OSB alternative that gives all of the benefits of OSB at a fraction of the price.
What is OSB?
OSB is engineered wood that is created when small wood strands are bonded together with adhesive resin and glue. These wood strands are arranged in cross-oriented layers, giving OSB its name. OSB panels come in a variety of sizes, types, and thicknesses. OSB is also known for being especially durable and strong—important qualities when it comes to a building’s structural support.
OSB was created in the 1960s as an alternative to plywood. It started gaining popularity in the 1970s when plywood production declined due to a lack of suitable timber. By the 1980s OSB was a leading structural sheathing material.
Today OSB remains a popular sheathing material that helps give buildings their structural integrity, provides a surface for fastening siding materials, and offers important insulation and thermal properties.
Why Consider an OSB Alternative
When builders first began using OSB regularly, it set records for new product adoption in North America, with 751 million square feet used in the 1980s to a staggering 7.6 billion square feet in 1990.
Since then OSB popularity has continued to grow. Today the OSB market has an expected compound annual growth rate of 9.5% from 2022 to 2028. And with high demand comes higher prices.
Other than rising costs, OSB can be susceptible to moisture. Although it does absorb water more slowly than plywood, OSB also dries slower, which can ultimately lead to fungi, wood rot, and mold as well as warping and swelling that inhibits the material from returning to its original shape.
Builders might also consider an OSB alternative because the resins used to create OSB can include and emit low levels of formaldehyde, which can cause health issues for occupants—including breathing problems and irritation to the eyes, nose, throat, and skin.
From a design perspective OSB is also notably challenging to paint because it lacks a smooth texture and, due its wood strand composition, can absorb paint.
3 Key OSB Alternatives
When it comes to finding an OSB alternative, these three options are comparable building materials fit for a variety of projects.
Fiberboard
Like OSB, fiberboard is an engineered wood material. However, where OSB is made using strands of wood, fiberboard is created when wood fibers are pressed and glued together.
Fiberboard comes in three densities: low-density fiberboard (LDF), also known as particle board; medium-density fiberboard (MDF); and high-density fiberboard (HDF), also referred to as hardboard. And because both materials are manufactured similarly, fiberboard matches OSB in durability. Fiberboard also makes a great OSB alternative because it is easily accessible and comes at a relatively low cost.
Rigid Foam Insulation
Foil-faced polyiso can act as a building’s air and water resistive barrier while meeting NFPA 285 fire codes, enabling the elimination of exterior gypsum and other air barriers. Photo courtesy of Rmax
Also known as rigid foam sheathing, rigid foam insulation is a continuous plastic foam that provides maximum thermal efficiency, as the absence of any gaps, holes, or leaks in the material itself can prevent air leaks, better control indoor temperatures, and help reduce a building’s energy use.
Rigid foam insulation also creates a strong barrier against moisture and comes in a variety of thicknesses. However, it is less stable than OSB and may require additional bracing. If you’re building a residential or commercial project in an area with high wind, you may want to consider an OSB alternative that provides greater structural strength. Additionally, rigid foam sheathing cannot withstand direct sunlight and will require proper siding for protection.
Like fiberboard, rigid foam insulation also comes at a lower price point.
Fiberglass-faced Gypsum Board
Photo courtesy of National Gypsum
Fiberglass-faced gypsum board is made up of a noncombustible interior panel with a fiberglass-reinforced gypsum core and coated fiberglass mat face. The fiberglass makes the panels highly moisture- and mold-resistant, and the material is also more stable and durable compared to other OSB alternatives. Because of its structural integrity, fiberglass-faced gypsum board can also withstand tough weather conditions.
Although fiberglass-faced gypsum board is cheaper than OSB, it can be more expensive than fiberboard and rigid foam insulation.
Which OSB Alternative Should You Choose?
Now that you understand the benefits of an OSB alternative and the options available, it’s time to decide which solution will work best for your project.
One of the most important factors is the location of the building and its climate. Projects in areas with high wind should include a strong OSB alternative that provides greater structural integrity, such as fiberboard or fiberglass-faced gypsum board. Meanwhile, projects in wet climates should opt for moisture-resistant solutions, which includes both rigid foam insulation and fiberglass-faced gypsum board.
If energy efficiency is a main goal of your project, rigid foam insulation might be the best choice. And where cost is concerned, fiberboard and rigid foam insulation are less expensive, while fiberglass-faced gypsum board can carry a higher price point.
At the end of the day, builders and architects looking for an OSB alternative have a few options that all come with comparable benefits. The right solution for you will ultimately come down to your project’s goals and needs—and your budget.
