Originally, part of the larger Cawdor Quarry complex, Permanite Asphalt was incorporated in 1989 and manufactured various asphalt products, mainly flooring blocks used to waterproof floors, as well as roofing sheets. The process involved the mixing of aggregate, bitumen, sand and limestone. The plant took powdered limestone from several of the local quarries and mixed it with hot bitumen emulsion that was brought down from the refineries of Ellesmere port, this being a bi-product of the fuel oil-refining process. The mixed tar and limestone solution was poured into metal moulds on the floor of the big shed and allowed to solidify, then the back-breaking process of manually separating and stacking the cooled blocks could begin. The site was regulated by the local Derbyshire Dales District Council on the condition that the heating of tar or bitumen is regulated under section 6.3 of the Environmental Permitting Regulations.


In 2009, Permanite Asphalt relocated to Grangemill, becoming known as Ruberoid, which is part of the IKO Group. The company was dissolved in September 2016.


In 2018, developers Groveholt Ltd submitted plans for 586 houses in total for the ‘Matlock Spa’ development - with 468 of the homes to be built on the brownfield sites of Cawdor quarry and the former Permanite works. Currently these plans have yet to get off the ground, and the site remains derelict.

Thanks to Wally_urbex on 28DL for the information.