It's a wood fiber board with a thin asphalt coating often called "buffalo board" or "beaverboard", the trade name of the long defunct Beaver Board Co. It was an inexpensive exterior wall sheathing. Like.
The best practice for increasing the R-value in exterior walls is to protect them with insulated foam sheathing. Some builders use 1/2-inch wood sheathing (R-0.6) or asphalt impregnated sheathing, usually called blackboard (R-1.3) to sheath the walls.
Fiberboard products have been widely used on building exteriors as a non-structural wall sheathing, even on some roofs as roof sheathing, and on building interiors as a ceiling or wall covering.
Fiberboard requires products or techniques to provide wind bracing and rigidity to the structure. Fiberboard sheathing does not hold screws well; it is also easy to strip the screw holes. Fiberboard sheathing is heavy because it is so dense, which can make it difficult to handle.Mar 25, 2020
5.0 per inchSTYROFOAM extruded polystyrene insulation is rated at an R-value of 5.0 per inch at 75°F.
R-Value Chart for EnerfoilTM Rigid Foam Faced InsulationThickness (Inches)R-value (in I-P/Imperial)RSI (R-value in Metric)1.06.21.081.59.31.622.012.42.162.515.52.76 more rows•Dec 13, 2018
Rigid insulation sheathing is made of a rigid plastic foam that is typically sold in 4×8- or 4×10-footboards. The boards are available in several thicknesses and R-values; 1-inch and 2-inch thicknesses are common. Rigid insulation provides thermal protection and it can also serve as an air and moisture barrier.Feb 18, 2021
For all structural purposes, plywood is much stronger than fiberboard, reveals Bob Vila. Plywood is made from several individual layers glued together perpendicular to each other to provide strength. Fiberboard is made from individual random chunks of wood glued together under pressure without grain patterns.
Usage of insulation board Insulation boards (also known as standard boards) are wooden fibreboards that are designed to offer additional insulation, sound muting and increase in constructional rigidity in constructions of interior walls, ceilings and floors.
Asbestos in Low Density Board (LDB) "Fiberboard" Products. Some low density fiberboard products like those described here were widely manufactured and distributed including in the U.K. and Australia; these products are particulary hazardous if disturbed as they are soft and they contain high levels of asbestos.Dec 15, 2012
The R-Value of 0.55 for 7/16" OSB was obtained from ASHRAE Handbook, Fundamentals.
BP Canada R-4 High Performance Insul-Sheathing combines the strength of wood fibres with type II polystyrene insulation, delivering true R-4 thermal resistance. This fibreboard has superior structural strength, while remaining lightweight and easy to install without the need for additional bracing.