Curtain walling to the hall, St Albans School

The glass in the old system decided how the job ran. It was 10mm float in a timber curtain wall that had been there long enough to be unpredictable, and float glass that thick breaks into long pieces rather than crumbs. We took it out bit by bit rather than by the panel, working across the elevation a piece at a time. It is the slow way to do it and it is the only sensible one.

The programme was term time, with exams due to start in the hall. That set the sequence more than anything else. The opening was made good and sheeted over at the end of each day so the building was secure and weathertight overnight, and the hall went back to the school in a usable state. The grand pianos were moved clear before anything started and the floor was boarded, because a parquet floor in a hall like this is not something you make good afterwards.

The replacement is a Smart MC600 Plus curtain wall, stick built, so the mullions and transoms were assembled in the opening rather than lifted in as finished units. That suits a working school, because the components come in through a door rather than over a roof. A fire exit door is built into the screen, and finger guards are fitted to the doors because the building is a school and the doors are used all day by pupils.

The hall is used for performances, and a wall of clear glass at that height puts daylight straight onto the stage. The top half of the screen carries blackout film and a curtain rail runs the width of the lower half, so the room can be darkened for a performance and opened up again for everything else it is used for.