Not all insulations are the same. There are several types of insulation to choose from: fiberglass or rockwool blankets or batts, spray foam, reflective, bubble, rigid board, loose fill and insulated panels. The right choice for a building should match the end-use needs of the building, energy code requirements, budget and your install capabilities.
The many reasons for and benefits of insulation
Another difference to note, particularly with metal building fiberglass insulation, is that it is commercial grade, predominantly manufactured with a higher tensile strength, and is specifically designed for use in metal buildings. In fact, most metal building insulation is certified specifically for use in metal buildings.
The primary reasons for metal building insulation are: (R-values or U-factors) required by the local or state energy code; condensation control; reduction in heating and cooling costs (in a conditioned buildings); reduction in noise; and the potential for more efficient lighting (attributed to the choice of vapor retarder, aka “facing” with insulation blankets).
It is the responsibility of all the parties involved in a metal building construct to ensure the correct insulation provisions are in place to meet all applicable energy code requirements. Consult the Department of Energy or www.energycodes.gov for the latest specifications for your future building’s location.
Above the Dew Point
Insulation controls condensation by regulating internal temperatures and keeping the surface temperature (of the building’s roof and or walls) above the dew point. When temperature and dew point meet at a fateful point, condensation builds up on the interior roof and walls. If insulation were left out of an area in a metal building, it will surely cause condensation. In extreme cases, it could rain in the building, and will definitely warrant a contractor/installer call back.
Part of the insulation solution and condensation control plan for your building needs to incorporate a vapor retarder. These facings respectively provide attributes over their primary role of inhibiting the passage of moisture through them (perm rating). Often the facing will act as the inner-wall material, so it has been reinforced with a layer of scrim (fiberglass or nylon mesh). When and where required, check with your manufacturer or provider for the facing’s ratings: perm, flame retardancy, etc.
Effectiveness and Benefits
For maximum effectiveness (and to meet most energy code requirements), insulation needs to be insulating material that is continuous across all structural members without thermal bridges other than fasteners and service openings. It is installed on the interior or exterior or is integral to any opaque surface of the building envelope.
An additional benefit of insulating the building envelope is the reduction of excessive noise—both from the outside in, and the inside out. There are some building codes that command certain sound transmission class (STC). The insulation manufacturer will be the best source for further information but know that the higher the noise reduction coefficient (NRC), the more improvement on the building STC rating.
Another, reason for insulating a metal building is to have a clean and improved interior finish with a potential for more efficient lighting. White facings have been specifically designed to provide a clean, bright finish. The reflectiveness of the facing itself may allow reduction in the number of skylights or light fixtures needed to achieve the required/desired effect. On the contrary, a black facing has been designed for surfaces in which you do not want to draw attention. These facings are most often used in theaters or restaurants.
The whys of insulating metal building are as numerous and as unique as the end uses and locations of your prospective building. For the best answers to your specific project questions, get and stay in touch with your building manufacturer, your suppliers, and most importantly, your local code official. Circling back and of course, there’s always the Metal Building Manufacturers Association (MBMA) and their wealth of knowledge, for reference though, use www.mbma.com/Learn_Glossary.ht… as a free resource.
Robert Tiffin is national accounts manager for Silvercote, Greenville, S.C. To learn more, visit www.silvercote.com or call (864) 603-2856.