Sika Sarnafil specified for NHBC head office in Milton Keynes

• Roofing contractor Itech Roofworks
• Main contractor Winter Refurbishments

Refurbishment work began after several water ingress issues were identified.  

Sarnafil was specified to ensure NHBC a full single point guarantee for waterproofing the building.

3 steps to roof replacement

1. overlayed the existing D100 metal deck with a T-fleece separation layer before mechanically fixing S327-18 EL membrane using the Sarnabar system.
2. installed profiled foam fillers to the existing profiled metal roofs
3. existing lightning protection was then removed to enable roofing works to be undertaken

Minimising water ingress

The existing roof membrane was cut at the perimeter and at all penetrations to alleviate built up stresses, all defective skirting and flashings were removed and the existing roof was  cleaned and prepared for the installation of the separation layer.  

S-Felt T Fleece was loose laid with 100mm laps.  Light Grey, S327-18EL Single Ply Roof Membrane was then loose laid in the same direction as the roof deck corrugations and secured using Sarnabars at 5m intervals.

These were installed at 90 degrees to the metal deck corrugations with Sarnafil BS-S stainless steel fasteners, ensuring the fasteners had penetrated through the deck by a minimum 15mm.

The Sarnabars were then weathered with 200mm of Sarnafil S327-18EL Light Grey cover strips, heat welded to the main roof membrane on each side of the Sarnabar and a 150mm up-stand was installed around the 11 existing roof lights in preparation for installation of replacement roof lights.

The Sarnabar system was chosen to ensure that disturbance to staff and members of the public was kept to a minimum.  

It meant the overlaying process could be done without the need for striping the whole roof which minimised water ingress or disruption.

Sika Sarnafil Area Refurbishment Manager, Neil Smith:  “The finished product looks very good and the client was extremely happy with the outcome.  The team at Itech Roofworks and Winter Refurbishments were great to work with and I would definitely recommend them” .

Itech Roofworks General Manager, Tony Reynolds: “We are really happy with the overall aesthetics of the project, as from the client, all the way down to Sika Sarnafil, the feedback has been enormously positive.”

Sika Sarnafil,
Watchmead,
Welwyn Garden City,
Hertfordshire,
AL7 1BQ,
United Kingdom

Phone: 01707 394444
Fax: 01707 329129

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