All cushions provide some level of thermal resistance that is, resistance to the – transfer of heat and cold through the floor. This is measured as an value. The ‘R’ higher the R value, the better the material is as a thermal insulator. Normally, this is directly related to the density and thickness of the underlay. Although higher R values are generally a desirable characteristic, it’s not always the case. If your customer has installed an underfloor heating system (also called heating’), you will actually want to use an underlay that lets the heat through. ‘radiant This means you will need to choose a thinner cushion, such as flat cellular sponge rubber or synthetic fibre cushion. Before you decide on the most appropriate underlay to use, always check to see whether the rooms you’ll be laying carpet in have an underfloor heating system. Classification There is an Australian Standard classification for the different types of cushion underlay, categorised according to their intended use or application. This is set out in Table 1 in AS 4288-2003 Soft underlays for textile floor coverings. The classification is based on the cushion’s performance in compression and deflection after A load (also called load) is one that dynamic loading. ‘dynamic’ ‘live’ is not constant, and includes foot and wheeled traffic. Note that a particular classification for a cushion does not mean it can’t be used in a different application. For example, an underlay classified as could be used in ‘luxury’ a commercial application where extra comfort or firmness is required. Below is a summary of Table 1 from AS 4288-2003. Designation Description of intended use or application LR residential use, not suitable for stairs GR General residential use L Luxury use, domestic/commercial where high energy absorption is desirable GC General commercial use, suitable for normal foot and wheel traffic HC Heavy commercial use, suitable for heavy foot and wheel traffic and castor chairs Learning activity
All cushions provide some level of thermal resistance – that is, resistance to the transfer of heat and cold through the floor. This is measured as an ‘R’ value. The higher the R value, the better the material is as a thermal insulator. Normally, this is directly related to the density and thickness of the underlay. Although higher R values are generally a desirable characteristic, it’s not always the case. If your customer has installed an underfloor heating system (also called ‘radiant heating’), you will actually want to use an underlay that lets the heat through. This means you will need to choose a thinner cushion, such as flat cellular sponge rubber or synthetic fibre cushion. Before you decide on the most appropriate underlay to use, always check to see whether the rooms you’ll be laying carpet in have an underfloor heating system. Classification There is an Australian Standard classification for the different types of cushion underlay, categorised according to their intended use or application. This is set out in Table 1 in AS 4288-2003 Soft underlays for textile floor coverings. The classification is based on the cushion’s performance in compression and deflection after dynamic loading. A ‘dynamic’ load (also called ‘live’ load) is one that is not constant, and includes foot and wheeled traffic. Note that a particular classification for a cushion does not mean it can’t be used in a different application. For example, an underlay classified as ‘luxury’ could be used in a commercial application where extra comfort or firmness is required. Below is a summary of Table 1 from AS 4288-2003. Designation Description of intended use or application LR residential use, not suitable for stairs GR General residential use L Luxury use, domestic/commercial where high energy absorption is desirable GC General commercial use, suitable for normal foot and wheel traffic HC Heavy commercial use, suitable for heavy foot and wheel traffic and castor chairs Learning activity
carpet_basics_learner_guide.docx