Technical Booklet H Stairs Ramps Guarding and Protection from Impact·Page 41·5.6
Child safety in guarding - sphere and climbability test
Where buildings may be used by children under 5, guarding must prevent a 100 mm sphere from passing through openings (except specified triangular openings) and prevent children from readily climbing up.
Where a building or part of a building is likely to be used by children under 5 years of age the guarding should be constructed so that a 100 mm diameter sphere cannot pass through any opening in it other than a triangular opening formed by a tread, a rise and the bottom edge of the guarding if that bottom edge is not more than 50 mm above the pitch line. The guarding should also be constructed so that a child cannot readily climb up it.
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