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Project Data

Architect: Architype

SubcontractorDiespeker (Interiors) Ltd 

Products used: Knauf Deflection Head Fire Seal (DHFS), Knauf Wall Liner, Knauf Isolator and Knauf Shaftwall


Project Details

Effective fire seal: installed in minutes


A range of Knauf products has been used in the construction of the St Loyes Extra Care Scheme in Exeter, but the stand-out product for the drywall contractor was the time-saving Knauf Deflection Head Fire Seal.


A solution for deflection head details was needed throughout the 53 unit, mixed-tenure development.  Traditional solutions use plasterboard fillets, which take time to cut and are fiddly to fit correctly. Knauf’s Deflection Head Fire Seal (DHFS), on the other hand, is supplied in highly-flexible 3.06m lengths. Fitting it to the partition top track takes seconds and is definitely a one-man job. Furthermore there is minimal wastage as offcuts and smaller pieces can be butted together.


Chris Williams, Contracts Manager, at Diespeker (Interiors) Ltd reported that his team were delighted with the product, finding it easy and quick to use. Chris also noted improved accuracy:


The product removes the quality risks of inaccuracies in the cutting of the head plasterboard on site. Prefabricated machine cut fillets procured off site is a common way of overcoming this; however, the waste from that solution can be high. Also, the potential for missed mastic between the track & board & board & soffit is removed.  I would happily use this product again & would be happy to promote this as a potential design solution with future clients.”


Knauf DHFS is an elastic polyurethane foam with intumescent firestop additives used to provide an effective fire and acoustic barrier in the construction of Knauf’s drywall partition deflection head details. It is designed to provide up to 25mm downward deflection capability or + or – 12.5mm deflection capability. When installed correctly within Knauf drywall systems, customers will also have the reassurance of Knauf’s full System Performance Warranty – in this project, the DHFS was used with Knauf partition systems throughout the facility.

Designed by Architype, the St Loyes Extra Care Scheme consists of one and two bedroom apartments providing an environment for older people to maintain an independent lifestyle that integrates various levels of care and support.

With quality of life a top priority, the scheme is designed to Passivhaus standards, providing a comfortable, healthy environment combined with dramatically reduced utility bills.

Knauf’s product range was used extensively throughout. The Wall Liner system corrects background irregularities and requires little or no background preparation, while the Isolator Twin Wall system reduces sound transmission between adjacent spaces. Knauf Shaftwall forms enclosures around service and lift shafts – even those where there is limited access from one side.

To see a video demonstration of the installation process, go here or for full more information visit