The Best Sheathing Alternative to Offset High OSB Prices

Oriented Strand Board (OSB) is a popular sheathing material for walls, roofing and subfloors. It first grew in popularity as a cheaper and stronger alternative to plywood, but the growing demand has caused the prices to escalate rapidly. OSB prices are projected to continue to rise, and inventory has become a significant issue.

At Atlas Molded Products, we offer OSB alternatives that are more cost- and labor-effective. By using a thin wall fiber sheathing product where the insulation is laminated onto the wall fiber sheathing, we are also able to provide substantial weather and air barriers and continuous insulation.

Let’s take a closer look at our ThermalStar Laminated Wall Insulation and Structural Wall Insulation products as well as their significant benefits.

Laminated Wall Insulation (LWI)

ThermalStar Laminated Wall Insulation (LWI) is used in designated nonstructural locations where SWI, OSB or other structural products are deemed unnecessary by the building codes. In fact, only about 50% of the exterior walls need structural sheathing.

There are several benefits to using ThermalStar LWI when applicable, the first being it’s less expensive compared to most structural sheathing options.

LWI creates a continuous system around the house and eliminates thermal bridging of the walls through the space between the studs. It also creates continuous insulation all around the house, providing continuous and stable R-value for the entire lifetime of the home and improving the energy efficiency and performance of the home — this earns substantial sustainability credits.

ThermalStar LWI has an integrated film facer, which serves as a code-compliant, water-resistant barrier (WRB). When the joints are properly flashed and taped, LWI acts as an air barrier component that limits air infiltration into the home. So, there is less concern over mold, mildew, rot and allergens.

Structural Wall Insulation (SWI)

ThermalStar Structural Wall Insulation (SWI) is a 4-in-1 product that provides structural benefits, high R-value, a water-resistant barrier and an air barrier component.

Atlas’ ThermalStar SWI comes in three sizes, two thicknesses and is more cost-effective than OSB. It also pairs perfectly with LWI for non-structural areas without sacrificing on the continuous insulation, R-value or weather and air barrier properties.

Depending on the design criteria, ThermalStar SWI can be installed with the rigid insulation layer facing outward or with the rigid insulation layer facing inwards towards the wall cavity.

Besides Cost, How Is Atlas SWI Better Than OSB?

With ThermalStar SWI, you get a 4-in-1 product. This means you only need one product to take the place of four, saving you money on multiple materials as well as the labor and effort to put four different products on. Because each of the other materials needs separate labor — for example, the person who puts on the sheathing won’t put on the vapor barrier — this eliminates the need for scheduling and paying multiple tradespeople.

OSB is strictly a structural component. It offers no insulation, no R-value and no weather-resistant component. In fact, any type of cut or defacement to an OSB panel is susceptible to fungi, mold and wood rot, and the resin used to manufacture OSB emits low levels of formaldehyde, known to cause irritation of the eyes, nose and throat, breathing problems and cancer.

OSB does provide great structural integrity, but most of the time, a house wrap is also needed in conjunction with OSB to create a weather-resistant barrier.

OSB also requires insulation added over top, so the R-value isn’t there without additional material. Without continuous insulation, the structure will likely not meet strict LEED requirements.

Atlas ThermalStar SWI takes care of all of this — and more.

SWI is made with Expanded Polystyrene (EPS) which is made of 98% air, and the R-value of the product remains stable and effective for the lifetime of the structure.

The closed-cell nature of EPS is already resistant to moisture, but ThermalStar SWI also comes with an integrated film facer that serves as a code-compliant water-resistive barrier and air barrier when properly flashed and taped.

Since ThermalStar is a 4-in-1 product, you will see significant savings on labor. With OSB, you would need to wrap it with a weather-resistant barrier and add additional insulation to make it energy efficient. With SWI, all those additional layers are included in a single, easy-to-install panel.

What Else Should You Know About Atlas’ Sheathing?

Whenever a builder uses OSB sheathing, an inspector must inspect the OSB first, and then they need to come back to inspect the house wrap. Inspections can take anywhere from one day to two weeks. If there are multiple parts, like OSB and the weather-proofing membrane, there will be time in between each inspection.

With SWI, once you nail it and tape it, the inspector can come in and inspect the whole product at once, limiting delays and saving considerable time. SWI also saves on the labor that would be used to install multiple building materials.

Here at Atlas, we are able to manufacture the Structural Wall Insulation, and even before the OSB price increases and shortages, we offered better performance and value with our 4-in-1 system.

There is no need to source several products to get the job done, especially if the alternative offers more benefits.

When it comes to the R-value of Atlas SWI and LWI insulation, two typical sizes are sold: R3 and R5. Some codes call for R5, R10 or R15 depending on the location and climate zone, so other sizes and R-Values are available on request.

Save Time & Money With Atlas Insulation