Builders recommend Certified Faced Insulations as an assurance that the insulation delivers the specified R-value.
Frequently Asked Questions
1. What is the difference between residential grade insulation and NIA Certified Faced Insulation®?
If residential grade insulation is used in a metal building, the R-value cannot be guaranteed because the lamination process of applying adhesives and a facing to residential grade insulation can greatly affect the thickness recovery and subsequently its effectiveness.
In addition, residential insulation is not manufactured to the widths and lengths needed to fit metal building construction.
2. How Should NIA Certified Faced Insulation® be stored at the job site?
Individual rolls of insulation should be packaged in ventilated bags.
Elevate material off ground or slab.
Cover material to protect it from weather.
Note: Freshly poured concrete gives off a significant quantity of moisture that is corrosive to facings containing aluminum foil or metallized film.
3. Why is it preferable not to pour concrete in an unventilated building?
Freshly poured concrete contains a tremendous amount of moisture (a 10' x 10' x 4' area of concrete contains approximately 24 gallons of water). As the concrete cures, much of this water is liberated into the air, increasing the relative humidity and vapor pressure within the building.
Ventilation is the simplest way to reduce humidity and vapor pressure and lower the probability of condensation related problems. Failure to adequately ventilate a building during and after a concrete pour can result in condensation on the surface of the vapor retarder and potentially within the insulation. This is particularly critical in colder temperatures.
4. What facing do you recommend for this proposed project?
Depending on the time of year that installation is taking place, the most important thing regarding the facing is that the permeance be .02. In addition, if installation is taking place in cold temperatures less than 30-40 degrees F, the exposed laminate of the facing should be a polypropylene in lieu of vinyl.
5. I am building a warehouse that will be unconditioned (no heat or air conditioning). Do I need to put any insulation in the building?
To avoid severe condensation problems (raining) inside the building, one should at least put a condensation blanket in the roof. Realistically, it doesn't cost much more to fully insulate the roof and it is so much more costly to try and retrofit a building later on. Therefore, because the use of the building may change in the future, it would be wise to insulate the building even if it is an unconditioned building.
6. The insulation got wet during installation. Can it still be used?
The chief concern with wet insulation is the possibility that contaminants may have been carried into the insulation by the water and that the dirt and contaminants can become a nutrient source for mold or mildew growth. For this reason, insulation manufacturers recommend that wet insulation not be installed, or be removed and replaced with new, clean, dry insulation. Studies have shown that wet insulation may be air-dried in place and, once dry, its thermal performance will be unaffected provided the original insulation thickness is maintained. However, if the source of water is contaminated or not known, the insulation must not be used.
7. The specification calls for NAIMA 202-96® (Rev. 2000) insulation. What does this mean?
This standard product specification for manufacturers, designers, and users of metal building insulation systems, promulgated by the North American Insulation Manufacturers Association (NAIMA), covers the classification, composition, and physical properties of flexible fiber glass insulation designed to be laminated with facings providing appropriate water vapor permeance, appearance, and durability properties, intended specifically for use in the walls and roofs of pre-engineered metal buildings. NAIMA 202-96® (Rev 2000) insulation has the strength needed to withstand the compressive forces of lamination and the resilience to recover sufficient thickness so it can deliver full thermal performance.
8. The specification calls for an insulation level of 19°F•hr•ft2/Btu. What does this mean?
The specification is calling for R-19 insulation. Units of R-value are (°F•hr•ft2)/Btu.
Heat flow is the transfer of energy from one area to another when there is a difference in temperature between the two areas. Heat flows from the higher temperature area to the lower temperature area by one or more of the three following ways: conduction, convection, and radiation.
10. The specification calls for an insulation level of 3.3m2•k/W. What does this mean?
The specification refers to metric (SI) R values. The conversion equation is RSI=0.176xR.
11. What is meant by k-value, C-value, and R-value?
All four factors are measure of an insulation system's thermal performance. Each factor denotes a different thermal performance characteristic. Here are the definitions:
k-value
k-value denotes a material's effective thermal conductivity, which is a measure of the time rate of steady heat flow through a unit area of a homogenous material induced by a unit temperature gradient perpendicular to that unit area. In simpler terms; how well a material will conduct heat. The lower the k-value of a material, the better its performance as an insulator.
In U.S. units, k = Btu•in/hr•ft2•°F
In SI units, λ= W/m•°C
For most materials, thermal conductivity varies with temperature. Normally, the lower the mean temperature, the lower the k-value - and the better the insulation performance. For building insulation materials, k-values are customarily reported at a mean temperature of 75°F, a compromise between winter and summer conditions. For industrial insulations, k-values are customarily reported over a range of mean temperatures.
C-value
C-value denotes a material's thermal conductance, which is a measure of the time rate of steady heat flow through a unit area of a material or construction induced by a unit temperature difference between the two surfaces of the material of specified thickness.
In U.S. units, C = Btu/hr•ft2•°F
In SI units, C = W/m2•°C
The C-value of a material is equal to the k-value divided by the thickness of the insulation. The lower the C-value of a material, the better its performance as an insulator. For example: if the C-value of one inch of fiber glass insulation is 0.24 Btu/hr•ft2•°F, the C-value of two inches of the same material will be 0.12.
U-value
U-value denotes a construction's thermal transmittance, or its overall heat transfer coefficient. This is similar to the C-value but is generally used in denoting the thermal conductance of a construction comprised of different materials, such as in a typical building envelope. It also includes the air film resistances on both sides of the construction.
In U.S. units, U = Btu/hr•ft2•°F
In SI units, U = W/m2•°C
The lower the U-value of the construction, the better its thermal insulation performance.
R-value
R-value denotes a material's thermal resistance, or how well it is able to retard heat flow. The higher the R-value, the better its performance as an insulator.
In U.S. units, R = hr•ft2•°F/Btu
In SI units, RSI = m2•°C/W
R-value is useful in determining the total thermal transmittance of a construction such as a building envelope. The R-values of all of the materials comprising the construction, plus the inside and outside air film resistances, are added: the reciprocal of this sum is the construction's U-value (R = 1/C).