Further information on R-Value

“R” stands for resistance to heat flow or Thermal Resistance Value (TRV). The higher the R-value, the greater the insulating effectiveness. R-value is measured through a series of industry standard tests and ethical manufacturers have their values certified by SABS. Manufacturers of insulation products print the R-value of their products on either bags or on labels attached to plain bags. In most cases, R-value is also printed on the facings of batts and rolls. On un-faced insulation, R-value may be printed on the product or indicated by stripe coding.

R Value = thickness of insulating material ÷ thermal conductivity of material.

With the introduction of uniform standards for measuring the effectiveness of various insulations, the Thermal Insulation Products & Systems Association of South Africa TIPSASA, has introduced a range of total recommended R-Values for each of 6 different Climatic Zones. Results are in fact, the TRV’s of the total system – including static air gaps and roofing materials – and cannot be compared with R values of the bulk insulation products. Make sure that test methods used are clearly declared in order to avoid a poor basis for comparison between different types of materials.

See R-value Chart & Legislation or R-values

Chart Legislation