STAIRS AND LADDERS K1 Alternating tread stairs Stairs, ladders and walkways. Code of practice forthe design of industrial stairs, permanent ladders 1.22 This type of stair is one of a number of and walkways, or BS 4211:1987 Specification for stair types designed to save space. The general ladders for permanent access to chimneys, other pattern of steps has alternate handed steps with high structures, silos and bins. part of the tread cut away; the user relies on familiarity and regular use for reasonable safety Handrails for stairs (see Diagram 9 ). 1.27 Stairs should have a handrail on at least 1.23 Alternating tread stairs should only be one side if they are less than 1m wide. They installed in one or more straight flights for a loft should have a handrail on both sides if they are conversion and then only when there is not wider. Handrails should be provided beside the enough space to accommodate a stair satisfying two bottom steps in public buildings and where paragraphs 1.1 to 1.17 above. It should only be stairs are intended to be used by people with used for access to one habitable room, together disabilities. See Approved Document M: Access if desired with a bathroom and/or a WC. This WC and facilities for disabled people. Elsewhere must not be the only WC in the dwelling. handrails need not be provided beside the two bottom steps. 1.24 Steps should be uniform with parallel nosings. The stair should have handrails on both In all buildings handrail height should be between ONLINEVERSIONsides and the treads should have slip resistant 900mm and 1000mm measured to the top of the surfaces. The tread sizes over the wider part of handrail from the pitch line or floor. the step should be in line with dimensions shown Handrails can form the top of a guarding if the in Table 1 with a maximum rise of 220mm and a heights can be matched. minimum going of 220mm. The provisions stated in paragraph 1.9 will apply. Guarding of stairs 1.28 Flights and landings should be guarded at the sides (see Diagram 11 ): Diagram 9 Alternating tread stair a. in dwellings – when there is a drop of more See paras 1.22–1.24than 600mm; b. in other buildings – when there are two or more risers. 1.29 Except on stairs in a building which is not likely to be used by children under 5 years the guarding to a flight should prevent children being held fast by the guarding. The construction should be such that: a. a 100mm sphere cannot pass throughany openings in the guarding; and ONLINEVERSION b. children will not readily be able to climbthe guarding. 1.30 The height of the guarding itself shouldbe as shown in Diagram 11 . Access for maintenance purposes 1.31 Where frequent access for maintenance will be required (e.g. at least once per month), provisions such as those suggested for private stairs in dwellings in this Approved Document, Fixed ladders or the guidance in BS 5395-3 on industrial stairs 1.25 A fixed ladder should have fixed handrails and ladders, will satisfy the requirement. on both sides and should only be installed for 1.32 Where access will be required less access in a loft conversion and then only when frequently it may be appropriate to use portable there is not enough space without alteration to ladders, etc. Provisions for safe use of such the existing space to accommodate a stair which temporary means of access are not coveredsatisfies paragraphs 1.1 to 1.17. It should be by Building Regulations, but they are coveredused for access to only one habitable room. by the Construction (Design and Management) Retractable ladders are not acceptable forRegulations 1994 . means of escape. For reference see Approved ONLINEVERSIONDocument B: Fire safety. 1.26 Stairs, ladders and walkways in industrial buildings should, as appropriate, be designed andconstructed in accordance with BS 5395-3:1985 Approved Document K Stairs, ladders and ramps9