R-value (insulation) contain no trapped CFCs or HFCs (e.g., half-pound low density foams). On certain brands, twenty-year tests have shown no shrinkage or reduction in insulating value. This has led to controversy as how to rate the insulation of these products. Many manufacturers will rate the R-value at the time of manufacture; critics argue that a more fair assessment would be its settled value. The foam industry adopted the LTTR (Long-Term Thermal Resistance) method, which rates the R-value based on a 15-year weighted average. However, the LTTR effectively provides only an eight-year aged R-value, short in the scale of a building that
Building Materials Holding Corporation Building Materials Holding Corporation Building Materials and Construction Solutions (BMC) is an American construction supply company with corporate headquarters in Raleigh, North Carolina. The company operates principally in the South and West regions of the United States and has in excess of 10,000 employees. BMC was founded in 1987 as a building materials distributor. BMC distributes building materials, manufactures building components, and provides construction services across the U.S. Ready-Frame was launched in 2013. This service provides professional builders with computerized pre-cut framing lumber for constructing roof and floor trusses. The online business, BuildwithBMC.com, was launched in 2015 and carries over