Fiberboard Sheathing

What types of wood fiber boards are available?

Wood fiber boards are produced for several different building applications, including thermal insulation, exterior wind protection and interior finishing. Each type is manufactured with a different density, thickness and fiber structure to provide the properties needed for its intended use.

Despite these differences, wood fiber boards share a porous structure that traps air within the material while allowing water vapor to pass through. The sections below explain how the main types differ and where they are used.

What are wood fiber insulation boards?

Wood fiber insulation boards are used in exterior walls, floors and other parts of the building envelope where additional thermal insulation is needed. Their relatively low density and porous structure trap air within the board, helping slow the transfer of heat.

Insulation boards are available in different thicknesses and sizes to meet different thermal insulation requirements. Thicker boards generally provide greater thermal resistance, but the required thickness depends on the building design and the level of insulation needed.

How do wood fiber wind barrier boards work?

Wood fiber wind barrier boards protect the insulation layer from wind and reduce uncontrolled airflow through the building assembly while remaining permeable to water vapor. They are generally thinner and denser than wood fiber insulation boards and provide the mechanical strength needed for exterior sheathing applications.

These boards are commonly installed on the exterior of timber-frame walls and behind ventilated facades. Depending on the installation system, boards may have straight edges or interlocking profiles. Wood fiber boards with tongue-and-groove joints create more continuous connections between adjacent boards, helping reduce air leakage at the joints

How are wood fiber boards used for interior finishing?

Wood fiber boards can also be used on interior walls and ceilings. Boards intended for these applications generally have a surface designed to accommodate subsequent finishing or to remain visible as wall or ceiling cladding.

Depending on the product, wood fiber ceiling boards and wall boards may be suitable for plastering or painting. Some products also provide sound absorption, helping reduce reflected sound and improve acoustic comfort within the room.

How do you choose the right wood fiber boards?

The intended function of the board should guide its selection. A board used primarily for thermal insulation has different requirements from fiberboard sheathing that also needs to provide wind protection or support a subsequent finish. The board also needs to work with the rest of the building structure. Before selecting a product, consider:

• the applications specified by the manufacturer;
• board thickness;
• edge profile;
• mechanical strength when the board will also serve as a wind barrier or a base for subsequent finishing.

How does thickness affect wood fiber boards?

Thickness determines how much insulation a wood fiber board can provide and where it can be used. Thicker boards slow heat transfer more effectively, but additional thickness is not always necessary. The right choice depends on whether the board is being used primarily for wind protection, additional insulation or as the main insulation layer. For example:

• 20–22 mm (~0.8–0.9 in.) wood fiber boards are commonly used as wind barrier boards or as an additional exterior layer that protects the insulation and reduces air movement through the structure;
• 40 mm (~1.6 in.) wood fiber boards can provide wind protection while adding a greater amount of thermal insulation;
• 60–100 mm (~2.4–3.9 in.) and thicker wood fiber insulation boards can provide a full thermal insulation layer where higher energy-efficiency requirements need to be met.