SIG Zinc clad demonstration house in Bedfordshire

SIG Zinc clad demonstration house in Bedfordshire

This Blunham, Bedfordshire home, with a zinc roof and cladding from SIG, is an eye-catching, modern build from Fairfield Homes.

The large house - some 2850ft2 consisting of four bedrooms and five living spaces – features a natural stone lower floor, and the crisp, modern detailing of the elZinc Rainbow Red cladding which sweeps over the roof.

Home-owner, Neil Shepherd, who is Managing Director of Fairfield Homes, explains the choice of Zinc for the house, “I wanted the stone to be the rustic element, and the metalwork to be crisp and clean. Zinc allowed us to get both the look we wanted and stability over time. Different techniques or other brands wouldn’t come with the assurance of colour fastness that elZinc has.”

elZinc Rainbow Red was chosen due to the colour’s strong visual performance across the full spectrum of brightness on various days.

The standing seam zinc roofing and cladding was installed by RFL Metal Roofing. One of the biggest challenges that the team overcame was to ensure that all the standing seams lined up between roof and cladding. The window reveals demonstrate that this was a job well done.

Three details make the zinc roofing and cladding on the house at Blunham stand out:

• The stone/cladding junction,
• The hidden boxed eaves gutter, and
• The vented low-level ridge detail.

Ventilated stone junction with zinc cladding detail
Stonework has a very uneven surface and making joins between very crisp materials and uneven materials is a challenge. Rather than try and scribe the cladding into the stone, the two materials are kept apart, and a black polyester powder coated aluminium mesh is slid into a chase cut into the stone cladding.

This gives the edge a very crisp finish with no sealant required. Behind the mesh, a fabricated lining plate hides the top of the timbers, completing the tidy effect whilst providing a ventilation gap all around the building.

Hidden box eaves gutter detail
The eaves gutters are pulled back from the eaves to create a shadow gap along the edge of the roof and free the eaves up from rainwater collection, thereby contributing to the effect of the cladding running over the roof.

The detail for the hidden gutter is a standard elZinc detail, adapted to be slightly wider to allow for RFL’s teams’ soldering equipment. An upstand to the rear prevents wind-blown water from entering the roof, and the lower edge has a 75mm upstand and a turnout of 30mm flush with to the line of the capping, which hooks onto the side of the gutter.

There are no steps in the gutter, they are single falls on all elevations, jointed with expansion joints as required (but not exceeding 6 metres). Similarly, all of the downpipes are exterior, except for the point at which the roof dips right down into a striking V shape.

Ventilated low level ridge detail
Finally, to complete the effect of ‘up and over’ roofing and cladding in one, the ventilated ridge detail was also adapted to ensure it was as low as it could be, whilst providing the necessary ventilation. The detail is similar to those which use a foam gasket, but this provides superior airflow.

The detail is formed by a partial clip 200mm wide, made of 1mm formed galvanised steel. This sits on the ridgeline every 400mm, above the rafters, and is screwed into the substrate. A continuous galvanised plate gives full cover of the roof sheet on either side, and then the elZinc ridge cap locks everything into place with a continuous airgap. Under the ridgeline the roof covering has a 65mm upstand and a 20mm turnout at the top, which stops any driving rain.

The house at Blunham consisted of 600m2 of zinc (4.2 tonnes) with four valleys and plenty of important detailing.

Thinking about specifying coloured zinc? Talk to SIG Zinc & Copper on 0330 123 1820 or contact them through their website

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