Simply put, R-value is the measure of a material’s resistance to heat flow. The higher the R-value, the better the material insulates. R-value is particularly important when considering what types of material to select for your roof since increasing the thickness of an insulating layer produces more thermal resistance.
For example, metal has a low R-value, meaning it is not a good insulation against heat or cold. In contrast, spray foam insulation has one of the highest ratings and is a terrific insulator. In addition, you want your roofing material to do more than just insulate. Besides insulating, it should help prevent the spread of flames (the C-value) in the event of a fire and block the transmission of sound much more effectively than fiberglass.
Proper insulation of a roof helps a business or homeowner use energy more efficiently, thus reducing the cost of heating and air-conditioning each month. New products are being developed every year that help increase the R and C-values of roofing materials. It’s not your job to keep track of these innovations, but a professional roofing company will know all the latest and greatest products.
Making sound decisions in designing, constructing, or updating dwellings and commercial spaces will significantly lower energy bills and help avoid adverse health effects. Systematic planning for energy efficiency also can assist prospective homeowners and businsses in qualifying for mortgages because lower bills translate into overall affordability. “Energy-efficient” mortgages provide buyers with special benefits when purchasing an energy-efficient property.
Another reason to consult a professional roofer when deciding upon roofing materials is that every country, and even different zones in each country, have building codes that require different R-values and C-values for roofing materials. Consulting a professional roofer will allow you to make sure your roof is built to code, is safe, and an effective barrier against both heat and cold.