As builders and developers we are always looking for alternatives to cut costs while raising the quality of our end product. Varying exterior sheathing options could help reduce costs. Metal stud framing is incredibly strong and often you can go with less structural sheeting options as alternatives to plywood. As a modular manufacturing company a lot of our wall panels are transported pre-sheathed. Often times on-site crews only have two people to install and manually pick up the panels. Because of this we need a plywood alternative that is both light and strong. Here are some of the options.
Gypsum Exterior Sheathing
Exterior gypsum sheathing is made of a gypsum core sandwiched between fiberglass mats. It provides fire resistance and can serve as a base for various types of exterior finishes, such as stucco. However, it is not as strong as plywood or OSB and may require additional bracing.
This is steel frame modular build we built in Louisiana. Using exterior gypsum sheathing(blue) of metal studs. It was used in tandem with plywood to reinforce the sheer wall. The cost of these is usually about 50 cent as square foot.
Structural Fiberboard Exterior Sheathing
Fiberboard Sheathing: This engineered wood/paper product is made from recycled wood materials. It has a smooth uniform finish with no knots or grains. While it is less dense than solid wood, it is more thermally resistant and dimensionally stable. It is also more affordable than solid wood. However, it is not as strong as solid wood, so it may not hold fasteners as well or provide as much structural integrity. Additional wall bracing may be required.
You can see in some of these rooms we use the black structural fiberboard sheeting as it has noise dampening qualities. But it can also be used outside as long as you cover it with an adequate vapor barrier.
Medium Density Fiberboard Exterior Sheathing
This is used a lot in cheaper furniture. Medium Density Fiberboard (MDF) sheathing is a type of building material made from wood fibers that are compressed and then bonded with resin. MDF sheathing can be used as a structural sheathing for exterior walls and roofs. It is not as strong as plywood or OSB, but it is more dimensionally stable and moisture-resistant.
Exterior Insulation and Finish Systems (EIFS)
The Exterior Insulation Finishing System (EIFS), alternatively called EWI (Exterior Wall Insulation Systems) or External Thermal Insulation Composite Systems (ETICS), is a cladding system that insulates and provides a waterproof surface to the exterior walls of a building. This system integrates several materials into a composite structure, providing an insulated and finished exterior. In simpler terms, an EIFS or ETICS can be described as a highly efficient thermal wrapping or façade insulation that is applied to the outer surfaces of a building. It is then coated with a durable, decorative, and protective wall finish, suitable for installation on any type of construction.
EIFS offer a number of advantages over other types of exterior cladding, including:
- Energy efficiency: EIFS can help to improve the energy efficiency of a building by providing continuous insulation. This can help to reduce heating and cooling costs.
- Durability: EIFS are resistant to moisture, wind, and other elements. This makes them a good choice for areas with harsh weather conditions.
- Aesthetics: EIFS can be finished in a variety of ways to match the style of the building. They can be made to look like stucco, brick, or other materials.
- Low maintenance: EIFS are relatively low-maintenance. They do not require painting or staining, and they can be cleaned with a mild soap and water solution.
A Exterior Insulation Finishing System (EIFS) on a commercial building in Lafayette,LA.
Rigid Foam Exterior Sheathing
Rigid foam sheathing is a type of insulation that is made from a plastic foam. It is typically used as an exterior sheathing material. Rigid foam sheathing is available in a variety of thicknesses and R-values, which measure its ability to resist heat transfer.
Expanded polystyrene (EPS) is the most common type of rigid foam sheathing. It is made from small polystyrene beads that are expanded with heat. EPS is a good insulator, but it is not as strong as other types of rigid foam sheathing.
Expanded polystyrene (EPS) being installed on an exterior service to add insulation.
Extruded polystyrene (XPS) is made by extruding molten polystyrene through a die. XPS is stronger than EPS and has a higher R-value. It is also more moisture resistant.
Polyisocyanurate (polyiso) is the strongest and most expensive type of rigid foam sheathing. It is also the most moisture resistant. Polyiso is often used in areas with high winds or earthquakes.