Before installing the staircase, fix a 100mm x 25mm timber to the stair string. This timber packer must not be fixed to the structure.

This is the ensure adequate room for the plasterboard and dab to finish behind the stair string reducing shrinkage in this area.

Chemical stud fixing should be used at maximum 600mm centres or every other riser (whichever is closer).

On stair winders the fixings should be increased to a minimum of 1 chemical stud fixing for every riser.

Where boxed in, provide support under the winder tread.