Modular fall arrest structure comprising T-shaped blocks

A structure comprises an array of individual T-shaped elements 1, each comprising a panel 2 with a planar support member 3 extending orthogonally away from a face of the panel 2. Most or all of the elements 1 are preferably arranged resting on their support members 3 with their panels 2 uppermost and horizontal, in contact with neighbouring panels 2, to form a fall-arresting surface. To fit within the walls (6, fig 4) of a particular building void, selected elements 1 may be inverted, resting on their panels 2 with a remote end of their support members 3 forming part of the fall-arresting surface. Infill blocks (7,8,9, figs 3-5) and/or spacer elements (10, figs 6 and 7) may be added, further to adjust the dimensions of the structure to fit a particular void. The panel 2 and support member 3 preferably comprise an integral moulding of polystyrene foam or the like.