The present paper reports the results of a test programme set up in collaboration with British Coal's Minestone Services Division, to determine the friction characteristics of special polypropylene reinforcement straps embedded in compacted colliery spoil and a granular material. These straps are being considered as an alternative to traditional high-adherence galvanised steel straps because of possible corrosion problems associated with the steel straps. Field and laboratory tests have been performed to assess the suitability of colliery discards as backfill material and the soil-strap interaction. The test results showed that the different types of fill gave different results for a particular strap type, the more angular fill being superior in terms of pull out resistance and friction values. Finally, the results provide information on the friction characteristics which can be used in the design of reinforced early retaining walls using compacted coal wastes as the fill material.