Fire Retarded Timber Stair Specification
The following specification is based on the TF2000 test regime and is the specification used by Prestoplan for all fire retarded stair construction:
All stair components including: Treads, risers, strings, apron linings, newels, balusters, and handrails shall be pre-cut and machined before treatment.
All components shall be vac-vac treated with Hickson timber products Dricon (or equivalent) to provide a notional Class 1 reaction to fire.
Assembly must use a thermosetting glue (eg Cascamite)
All stair trunks must be under drawn with 12.5mm gypsum plasterboard or equivalent with support at no greater than 600mm centres. (This often requires a central nogging below the tread.)
Final decoration should be with paints / varnishes which suppress surface spread of flame.
Prestoplan have also developed solutions using steel stairs should the Client desire such a solution.
