First published in the November 2021 issue of Metal Architecture. Written by David Tomchak, Director of Marketing, Bay Insulation Systems

Not all insulation materials are the same. There are various reasons to use insulation, ranging from keeping cool spaces cool or keeping warm spaces warm, to keeping noise in or keeping noise out, or for fire protection, etc. The best advice we can give is to first understand what you need to insulate (type of building), and more importantly, why you need to insulate it (occupied versus storage versus heated versus semi-conditioned, etc.). For the purposes of this article, we will be focused on fiberglass metal building insulation.

Needless to say, one of the most common uses of metal building insulation, or reasons to insulate a Metal Building, is to meet the code requirement for energy usage. In order to determine what you need, you first have to establish the purpose of your metal building, as it will help you understand what type of energy performance is needed. The next step is to know the Climate Zone for the location of the building, along with the energy requirements of the local jurisdiction. Depending on the list of parameters just described, there are many combinations of R-values, facings and systems to choose from, and there may be more than one potential solution for your energy requirements. Each potential option will have various associated material costs, installation costs and lead times. The best advice we can give you is to rely on your building supplier and your insulation system supplier to help you sort through the requirements and assist you with specifying the insulation system best suited to meet your building’s budget and energy needs.

While having the correct combination of materials (or insulation system) needed to meet your building’s energy needs, it is also very important to understand the physical properties of the metal building insulation you will specify and use for your project. Knowing this information will ensure that the metal building insulation you will be using will meet all the criteria that you just spent valuable time determining. What follows is the minimum checklist of questions you can ask your supplier to make sure that you are obtaining the highest quality insulation for your &/or your client’s needs.

All unfaced Metal Building Insulation should be in accordance with ASTM C991-Type I, Standard Specification for Flexible Fibrous Glass Insulation for Metal Buildings.

All faced (or laminated) Metal Building Insulation should be in accordance with ASTM C991-Type II, Standard Specification for Flexible Fibrous Glass Insulation for Metal Buildings.

By making sure that the Metal Building Insulation you are specifying and using is per the ASTM C991, Type I & Type II Standard, you are ensuring that the insulation meets the following physical properties: Thermal resistance (stated R-value), surface burning characteristics and combustion characteristics (meets the 25/50 Flame Spread, Smoke Developed criteria), water vapor sorption, fungi resistance, corrosiveness, odor emission, dimensional tolerances, and humid aging. In order for a manufacturer or supplier to make the claim that their Metal Building Insulation meets ASTM C991-Type I & Type II, they must prove that the insulation has been fully tested to the standard and passes all the tests related to that standard.

The best way to make sure that the insulation you use meets this specification is to look at the product label. Each insulation product label should list the stated R-value, along with the mark of an independent testing lab that verifies the R-value. One common mark would be the Home Innovations Laboratory mark, as shown in fig. 1. The label should also list the surface burning characteristics of the product, along with the mark of an independent testing lab that verifies the surface burning characteristics. One common mark would be Underwriter’s Laboratories, as shown in fig. 2.

Lastly, ask the manufacturer &/or insulation supplier to provide you with the product specification for the Metal Building Insulation, which should clearly state that the product meets the ASTM C991 Standard for Type I (unfaced Metal Building Insulation) &/or Type II (faced Metal Building Insulation).