The construction of timber stairs, especially of the more elaborate type, has always been regarded as the cream of joiner's work to be given to selected craftsmen in the shop. When, as is usual in public and industrial buildings, the stairs are of concrete, it is still the carpenter who makes and fixes the formwork and knowledge of requirements to hold and support the wet concrete are largely responsible for the success of the job. The construction of stairs is governed by the 1985 Building Regulations "Stairways and Ramps Detailed in Approved Document "Stairways, Ramps and Guards". The casting of the stairs is usually carried out as a separate operation from that of the main structure so as not to delay the main structural work, a key being left in the face of the edge beam or trimmer to the floor to take the stairs.