6 - Association of Interior Specialists

Partitioning system ancillaries 7designed deflection level, securing the glass at all times(see figures 41 and 42).Appropriate steps need to be taken when installing atabutments to ensure that the upper section can deflectthrough the abutment if necessary. Notching of the upperand lower sections will be required at three way junctionsto allow the sections and glass to pass through. The lowerdeflection head section will need to be joined at alljunctions, using an appropriate splice plate.Some manufacturers offer a factory produced notchingfacility which saves on site time, others need to train theirnominated contractors to undertake this really importanttask correctly. This facility is offered by manufacturers forboth single and double glazed systems (see figure 43).7.6.2 Stud and board drywall systemsPlasterboard manufacturers offer a range of deflection headsolutions that can provide ±25mm movement and 15mm to50mm downward movement together with fire resistance of60 to 120 minutes.In principle the systems use a 50mm fixing strap betweentwo layers of plasterboard into which the uppermost fixingshould be made, being careful to ensure that it does not fixinto the system head track.Figure 44Figure 43Figure 41 Figure 42Always check with manufacturers as to what individualsystems can achieve.At present the most widely used systems with a lot ofdeflection head detailing are glazing and drywall.7.6.1 Glazing systemTo construct a deflection head detail involves the use oftwo sections at the head of the partition. The upper onefixed to the soffit in the normal way, and a lower section,housing the top of the glass, which either slides inside oroutside the upper section depending on the system design.The sections are designed to allow sufficient space for thelower section to move upwards or downwards to the46