Metal Building Insulation General FAQs
Q: What is a utility blanket used for in insulation?
Utility Blanket is 2” thick fiberglass (R-7) that is to be faced with an appropriate and adequate vapor retardant facing and is installed between roof or wall panels and the building’s secondary structural members to act as condensation and/or noise control.
Q: What does Certified R mean in insulation?
Certified R is similar to Utility Blanket in that is made to be faced but is available in greater thicknesses than Utility Blanket and is used to retard heat flow from or in to a building. It is manufactured in such a way that it will recover its manufactured R-value after lamination, if laminated properly. Certified R is an Owens Corning product that is manufactured specifically to be laminated to a vapor retardant facing and is capable of maintaining its advertised R-value after having been laminated properly. Certified R insulation must have ink-jet-printed on it the NAIMA 202-96 designation, which is the manufacturer’s third party certification that it is, in fact, the labeled R-value (see below).
Manville’s similar product is “MicroLite L”. Certainteed’s similar product is “Certainteed Metal Building Insulation”. Knauf’s similar product is “Knauf Metal Building Insulation”.
Q: What is MBI Plus in insulation?
MBI Plus is fiberglass insulation that is not meant to be faced with a vapor retarder and in fact may not recover to its original R-value if it is faced. MBI Plus is meant to be used as a second layer of fiberglass outside the faced layer of Certified R fiberglass where higher overall R-values are desired.
Q: What do Utility Blankets, Certified R, and MBI Plus have in common?
A: Utility Blanket, Certified R, and MBI Plus are all types of fiberglass insulation used in pre-engineered metal buildings.
Q: What is “NAIMA 202-96”?
A: “NAIMA 202-96” is the certification designation granted by the Home Innovation Research Labs (formerly National Association of Home Builders), a third-party testing service, to fiberglass manufactured to be laminated and certifies that the insulation thus certified meets certain minimum standards, such as width, length, and R-value. NAIMA 202-96 is a certification used by fiberglass manufacturers.
Q: What is “Certified Faced Insulation”?
A: “Certified Faced Insulation” is the certification designation granted by the Home Innovation Research Labs (formerly National Association of Home Builders), a third-party testing service, to vapor-retardant-faced insulation produced by an insulation laminating company and certifies that the insulation thus certified meets certain minimum standards, such as width, length, and R-value. “Certified Faced Insulation” is a certification used by fiberglass laminators. Only insulation that has been laminated using NAIMA 202-96 certified insulation can meet the requirements of the Certified Faced Insulation certification.
Q: What is the density of fiberglass metal building insulation?
A: In the past, the major manufacturers of metal building insulation posted and advertised the density of the fiberglass they produced. This is no longer done. The labels that the manufacturers adhere to their rolls of insulation give the R-value, the thickness, the width, and the length of the product, but do not mention the density. That is because the density is now considered proprietary information due to the fact that the manufacturers adjust the density to achieve the desired R-value, which is what they sell. R-values. The resultant R-value that is posted on the label of the insulation is achieved by adjusting the density. The bottom line is that the fiberglass manufacturers are not selling density and they are not selling thickness; they are selling R-value.
Q: What is the longest roll of faced fiberglass I can purchase?
A: A more relevant question would be, “what is the most realistic maximum length of faced insulation roll can I purchase?” We have learned that we are capable of producing rolls that are much too large and heavy to be handled on a jobsite. We have had instances where people have stated that the long roll lengths they had asked for were too cumbersome to be practical in the field. Therefore, as a guide, consider that the most realistic maximum roll lengths would be for 2” thick, 300 linear feet (282 pounds); 3” thick, 270 linear feet (368 pounds); 4” thick, 240 linear feet (414 pounds); 5” thick, 225 linear feet (455 pounds); 6” thick, 210 linear feet (497 pounds); 8” thick, 140 linear feet (435 pounds); and 9” thick, 100 linear feet (425 pounds).
Q: What is the widest roll of metal building fiberglass I can purchase?
A: Standard roll widths of metal building insulation are 36”, 48”, 60”, and 72”. 72” is the widest insulation we laminate.
Q: What is the maximum fiberglass insulation thickness fiberglass I can purchase?
A: Standard metal building thickness are 2”, (R-7), 3.4” (R-10), 3.7” (R-11), 4.3” (R-13), 5.3” (R-16), 6.3” (R-19), 8.0” (R-25), and 9.25” (R-30). 9.25” (R-30) is the thickest metal building insulation that can be purchased. While Utility Blanket is available only in the 2” thickness, both Certified R and MBI Plus are available in the thickness mentioned in the FAQ above, with the exception of 2”.
Q: What causes condensation in a metal building?
A: To answer this question, it is helpful to consider whether the condensation is forming on a structural member of a building and/or on the vapor retardant facing of the roof and/or wall insulation, or whether it is forming on the inside surface of a roof and/or wall panel behind the insulation.
Condensation in a metal building forms on a metal surface inside the building or on the interior side of the vapor retardant facing on the insulation is caused by the moisture that is dissolved in the air (water vapor) coming in contact with a surface that is at or below the condensation (dew) point. (The condensation point is dependent on relative humidity.) When water vapor comes in contact with something that is at or below the dew point, the vapor condenses at the point of contact and is seen as water in the liquid state. Condensation on the interior surface of a vapor retarder is evidence that the vapor retarder is relatively effective, in that the water on the inside of the vapor retarder has not gotten through the retarder and in to the fiberglass insulation, thereby reducing the effectiveness of the insulation.
When condensation forms on the interior surface of a roof or wall panel, behind the insulation, it is evident that water vapor has either gotten through or around the vapor retardant facing, and has then condensed on the inside surface of the wall or roof panel. Water vapor can get through a vapor retarder (it is not a barrier) if the vapor pressure between the interior and the exterior of a building is too great or if a vapor retarder with an insufficient perm rating has been used. Water vapor can get around a vapor retardant facing wherever there are holes in the facing, where insulation splices have not been properly made, or where the facing has not been adequately sealed around necessary penetrations such plumbing and/or electrical fixtures.
Q: What is “Perm Rating”?
A: The simplest explanation of perm (permeance) rating is that the rating measures the amount of water vapor (gaseous water) that can penetrate the retarder under certain conditions. The lower the perm rating, the less water vapor can permeate the facing. Facings are currently available with perm ratings ranging from 0.02 through 0.9, with 0.02 being the best.
Q: If MBI fiberglass insulation gets wet, does that mean it needs to be replaced?
A: Fiberglass insulation that has gotten wet from storm waters or flood waters should be removed and replaced. Those sources of water have a high probability of containing contaminants such as mold, mildew, or food sources that might support the growth of mold or mildew. Fiberglass metal building insulation must pass the mold growth test as specified in ASTM C991. Since there is no effective or practical method to determine compliance with that test after insulation has gotten wet from flood or storm water, it is recommended that the insulation be removed and replaced.
Testing has shown that fiberglass that has gotten wet recovers its thermal resistance and acoustic properties when it has been allowed to completely dry.
Fiberglass insulation that has gotten wet from rain or snow during installation may recover its full R-value if it is allowed to completely dry out and recover its original thickness. It is, however, very difficult to ascertain whether or not the insulation has dried completely or if it has fully recovered its original thickness if it has gotten wet enough to compact.
It is also important that there are no contaminants in the water that will contribute to mold or mildew growth. If the wet insulation is able to dry completely, if the thickness is able to recover, and it can be ascertained that no contaminants such as mold or mildew have gotten in to the fiberglass, the fiberglass should recover its original R-value and be safe to use.
Q: Does metal building fiberglass insulation cause cancer? Is it a carcinogen?
A: In October of 2001, the International Agency for Research on Cancer (IARC) changed the classification of “insulation glass wool” from Group 2B (possibly carcinogenic) to Group 3 (not classifiable as to its carcinogenicity to humans).
On June , 2011, the National Toxicology Program (NTP) removed from its list of “Reasonably Anticipated To Be Carcinogens” biosoluble glass wool fibers. This change means that a cancer warning label for biosoluble fiberglass home and commercial insulation is no longer required under federal law.
Biosoluble fiber is one that dissolves readily in the lungs, as opposed to biopersistent fibers, which remain in the lungs for a much longer time. Biopersistent fibers are not used for insulation.
NAIMA, the North American Insulation Manufacturers Association, has, since the 1930s, asserted that biosoluble fibers are safe to manufacture, install, and use, when the proper procedures are followed.
Q: Why does fiberglass insulation make me itch?
A: Fiberglass insulation is made from very fine glass fibers that are spun and woven in to a blanket. The glass fibers are so thin that they break easily and often do when they touch, for instance, your arms or hands. The fibers break off and stick in to the skin surface they come in touch with.
The new EcoTouch insulation, by Owens Corning, uses glass fibers that are of a different length and different diameter, and uses a different bio(plant)-based binder. This new insulation causes much less itching.
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