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
Trade Unions International of Building, Wood, Building Materials and Allied Industries Trade Unions International of Building, Wood, Building Materials and Allied Industries The Trade Unions International of Building, Wood, Building Materials and Industries, also known as the Trade Unions International of Construction, Wood, Building Materials and Industries, or by its French acronym UITBB ("Union internationale des syndicats des travailleurs du bâtiment, du bois et des matériaux de construction") is a Trade Union International affiliated with the World Federation of Trade Unions. The UITBB was founded at a conference in Milan in 14–16 July 1949. The highest organization is the Conference which meets every 4 years. Between conferences, the union is run