What Is Sheathing In Construction?
What Is Sheathing In Construction?
In construction, sheathing refers to a layer of the board or panel material used to protect the framing of a building’s floors, walls, and roofs. It covers the entire building framework, giving it a solid structure, and is typically applied before the installation of aesthetic features such as roof shingles or brick veneer. Sheathing can also help to improve the structural stability and energy efficiency of a building.
The sheathing is a board or panel material layer used to strengthen and protect various parts of a building, including the floors, walls, and roofs.
It provides a surface for other materials to be applied to and may offer some degree of weather resistance. Common materials used for sheathing include engineered timber, plywood, gypsum, and oriented strand board (OSB).
Floor sheathing is typically installed after the floor frame has been built but before the walls have been constructed. It is a tongue and groove material that helps to transfer live loads down to the floor joists beneath.
Wall sheathing can be structural or non-structural and can help to protect external walls against wind and water penetration. Roof sheathing is generally structural, as it helps to brace the roof frame. A covering is typically applied over the top of the roof sheathing.
What Does Sheathing Do?
The sheathing is a type of material that is used to protect and strengthen the structure of a building. It is typically applied to the exterior walls, floors, and roofs of a building and serves several purposes.
Exterior wall sheathing can be either structural or nonstructural. Structural sheathing provides support to the building and helps to prevent swaying or bending during extreme weather conditions or when the foundation settles.
Nonstructural sheathing provides insulation and helps to keep heat in and wind and water out. Floor sheathing provides a platform for workers during construction and also offers structural support by transferring live loads from the floors and joist beams to the ground below.
Roof sheathing provides lateral support to the roof frame, helps distribute weight evenly across the roof to prevent sagging or bowing, and acts as a foundation for roofing materials like shingles to help prevent leaks.
How Does Exterior Sheathing Work?
Exterior wall sheathing serves several purposes. It helps to strengthen and stabilize the walls of a building by tying together the wall studs and providing a solid base for siding materials to be attached.
Structural sheathing, made of materials such as wood or gypsum, helps to prevent the walls from twisting or bending under external forces such as wind or house settlement.
Overall, exterior sheathing helps to create a more stable exterior for a building, improving its ability to withstand various pressures and forces.
What Is Non Structural Exterior Wall Sheathing?
Non-structural exterior wall sheathing is a material that is used to create a tight building envelope in order to improve energy efficiency and reduce energy bills.
It is applied either to the outside or inside of structural sheathing, or directly to the studs if they have been supported by diagonal bracing.
Non-structural sheathing helps to keep out wind and rain and also provides insulation by sealing up air leaks and covering areas where traditional wall insulation may not be effective.
It should be used in combination with structural sheathing or diagonal bracing, as it does not provide structural support on its own.
Types Of Exterior Wall Sheathing
There are various materials available for use as external wall sheathing, each of which has its own unique characteristics, advantages, disadvantages, and price point. These differences can influence which material is the most suitable choice for a particular project or objective.
Oriented Strand Board Exterior Wall Sheathing (OSB)
Exterior wall sheathing refers to the material used to cover the exterior walls of a building. One type of exterior wall sheathing is oriented strand board (OSB), which is made up of thin wood strands that have been pressed together with resin and wax adhesives.
OSB is known for its durability and relatively low cost, but it can absorb water and swell if exposed to moisture over a long period of time.
To install OSB, it should be hung vertically over the entire exterior of the building, with the first panel starting at the side of the home and the long edge flush with the corner of the building.
The panels should be nailed together with 8d nails placed every 6 inches along the seams and wherever there is a stud behind the plane of the panel.
It is important to leave a small gap between the edges of the panels to allow for swelling. OSB should be covered with siding as soon as it is installed to protect it from rain and moisture.
Structural Fiberboard Exterior Sheathing
Structural fiberboard is a type of exterior sheathing made from plant cellulose fibers mixed with adhesives and coated with a water-resistant material. It offers some insulation and sound reduction properties, as well as structural stability.
However, it is not as strong as other materials and may require additional bracing in certain applications. It can be difficult to install due to its weight and tendency to strip screw holes, and it is a relatively expensive material.
To install structural fiberboard, it is recommended to have at least two people handling each panel and to nail or drill pilot holes rather than using screws whenever possible.
It can be installed vertically, with the long edge flush to the edge of the studs and the bottom edge reaching to the top of the sill, and can be butt-edged across the installation.
Plywood Sheathing
Plywood is a commonly used material for external structural sheathing due to its stability and moisture resistance. It is made up of thin layers of wood, or plys, that are layered in opposite directions for added strength.
It is lightweight, easy to install, and dries quickly, but it may have weak spots that can affect its structural soundness and it is more expensive to purchase than some other materials.
To install plywood sheathing, place it vertically and use 2-inch nails spaced 6 inches apart on the edges and no more than 12 inches apart on the center.
Make sure to start each new row at least 3 stud bays off from the first and mark door and window openings with tick marks.
It is recommended to use house wrap over the plywood before installing the siding. A 500-square-foot installation of construction-grade plywood will cost approximately $650 installed, with $490 for installation and $160 in materials.
Foam Board Wall Sheathing
Foam board wall sheathing is a non-structural insulation material that is installed to help improve the energy efficiency of a home by reducing thermal transfer and covering areas prone to air leaks.
It can be installed after structural sheathing, over existing siding before new siding is added, or on its own if the studs have been diagonally braced for stability.
While foam board can help reduce building costs and energy bills over time, it requires precise installation and proper sealing to be effective, and it has limited structural integrity, so it may increase the cost of a project upfront. The cost of installing foam board wall sheathing is around $2.50 per square foot for both materials and labor, and it is installed vertically, screwed to the sheathing or studs, and sealed with tape.
Gypsum Exterior Wall Sheathing
Gypsum exterior wall sheathing is a type of sheetrock that is used in outdoor construction. It can be made of gypsum alone or combined with fiberglass, and it may have a waterproof exterior finish.
Gypsum sheathing has several advantages, including its fireproof nature and its strength and durability compared to other materials like fiberboard, OSB, and plywood.
However, it is not as flexible as other materials, so it cannot be installed around curves or easily absorb impacts without cracking or crumbling. The cost to install gypsum sheathing is around $2 per square foot, with labor and materials each making up about half of the total cost.
To install gypsum sheathing, it can be cut to fit around openings and then screwed into place using 2-inch screws spaced 6 inches apart around the perimeter.
It can be installed either vertically or horizontally, with the edges butted together without a gap. It is important to minimize the number of joints and to leave a small gap between the gypsum and other materials or openings.
Diagonal Tongue and Groove Exterior Wall Sheathing
Diagonal tongue and groove exterior wall sheathing is a building material that is used to create a strong and stable exterior surface for a home.
It involves installing tongue and groove boards diagonally across the studs of the home, using materials such as fir and pine.
While this method of sheathing can be cost-effective due to the availability of inexpensive materials, it may be difficult to find installers who are familiar with the process and the materials may also be harder to come by.
Additionally, installation can be time-consuming as each board must be fitted into place and nailed onto the studs, which may result in higher labor costs.
Overall, while the diagonal tongue and groove sheathing can provide a durable exterior surface, it may not be as widely available or as easy to install as other materials such as OSB or plywood.
