Tarmac Group 1964, now group managing director, Martin acquired key quarrying assets, including Cliffe Hill Granite, Rowley Regis Granite and Hillhead Hughes. In 1968, Martin engineered the three way merger between Tarmac, Derbyshire Stone and the Scottish Asphalt company, William Briggs, creating the country's "largest roadstone and construction group". The group was briefly known as Tarmac Derby but the Derby name was later dropped. Further acquisitions were to come. Permanite, Britain's biggest roofing felt manufacturer, and Limmer, a quoted asphalt company, were bought in 1971, while the 1973 purchase of Mitchell Construction (which had foundered on the Kariba Dam) strengthened the construction
Playground surfacing States and Canada the International Play Equipment Manufacturers Association (IPEMA) provides a third-party certification service enabled by appointing a testing laboratory to determine if a particular surface conforms to ASTM standards F1292, F1951, and F2075. IPEMA’s seal on a provider’s document is clear evidence that the covered material has met these tests. Owner/operators should request a copy of this certification for their own protection. Some suppliers do not offer proof of certification and mere membership in IPEMA does not mean that a particular supplier’s material has been certified. A list of certified suppliers can be found at www.ipema.org. Playground surfacing