Details of installing new steel staircase in an existing concrete slab

Personnel Staircase done by
TAS Engineering Limited, Unit 1, Millers Lane, Grain Warehouse Yard, Derby Street, Burton on Trent, DE14 2NS.

This is one of our most recent projects and has involved close liaison with several other trades to produce a factory staircase that appears to be totally integrated into the building and not put in as a secondary thought.


The objective of this project was to create a new personnel route through the factory from the first floor changing rooms down to the ground floor production areas. It has taken over seven months to complete from agreement of designs to final opening. We have been involved from the start of it when the layout of the steel structure was decided upon. Our first task was to install floor strengthening steel work to prepare the floor to be sawn out to receive the new steel stairs. This picture shows the second main beam being bolted up. The steel is supported on a special purpose lifting cage to prevent it moving whilst being connected.


To enable us to fix the floor strengthening steel work the concrete casing was broken out on the existing beams and beam connection stools were welded on to enable the two main beams to be lifted into position. These were from 406 x 178 x 54 universal beam, shot blasted and zinc phosphate prime painted. The two smaller beams were cleat connected to the main beams and then all gaps between the steels and the hollow core planks were shimmed and tack welded. Once the aperture had been cut out of the floor we could then install the stairs and landing. The first flight was 17 steps at 1.5 metres wide down to a landing 1.7 metres wide by 4.0 metres long then down a second flight of 12 steps to ground level. This is shown with the stringers in place prior to the treads being attached.


Upon completion of the structure it was fixed down to the floor, fixed to the back wall and all major bolted connections were tack welded to prevent any movement whilst the block work was being put up. The stringers for these stairs were underslung so that the block walls would come flush with the edge of the stair treads to give a smooth transition and fulfil the hygiene and cleaning requirements. As the block work went up we welded tags to the stringers and landing legs to tie into the walls. This increased the rigidity of the structure which was important to prevent any cracking of the tiled surfaces at a later date.



This overlap detail served two purposes, the first being to allow a bolted connection which allowed the structure to be built up on site in small sections. The second was to allow the ceramic tiles to sit correctly on the finished treads as the nosing tiles are approximately half the thickness of the main tread tiles. This enclosed tread detail is not typical of a standard fire escape or factory staircase and required us to work to a total limit of 1mm on the pressings. Any deviation from this would have meant that the treads either didn't sit on the angles or the bolts would not tighten the two treads together.



This is the view of the stairs and landing prior to any block work being done. It shows one of the main floor strengthening beams which has yet to be fire boarded and clad. The smaller floor strengthening beams are out of view but are on the centre lines of the existing walls (either side). There is a step between the existing walls and where the new stair walls are to be built. These will be clad with hygienic composite panels that are widespread through the rest of the factory and this will take the step out, creating a cleaner and brighter thoroughfare. All steel work is shot blasted and zinc phosphate prime painted but the exposed faces of the stair treads and landing were left just shot blasted. This was to provide a key for the epoxy tile cement to grip to.

The finished stairs looking down to the landing showing the clean lines of the hygienic panelling and the transition of the old corridor tiles to the new stair tread tiles. These panels are the same as those used to construct cold stores. It has a pleasing appearance, is hygienic and is fully functional.