I came in at a rather late stage in the project where a old office building is being converted into a hotel. The wiring for the lighting was mistakenly routed above the compartment ceilings in the floor void above. The ceilings then had a small number of recessed downlights which were fire rated at 90min. The arrangement has been rejected by Building Control as there is no test evidence for the composite. So be careful when going for similar arrangements! I imagine recent serious fires are beginning to have an impact on the way regulations are interpreted.
