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
Good Building Design and Construction in the Philippines the weight of the structure. It must be composed of bedrock and must not be landfilled and is away from slopes and river beds. Broken rough rocks and fine sand must be used and must be free from external sediments as it may affect the strength of the concrete mix. Good Building Design and Construction in the Philippines The Good Building Design and Construction in the Philippines is a handbook developed in cooperation with the German Technical Cooperation (GTZ), UNDP Regional Center in Bangkok, and the Secretariat of the United Nations International Strategy for Disaster Reduction. The handbook aims to