THE DRAMATIC boomerang-shaped roof at an award-winning country house in Stirlingshire has been created using 900m2 of CUPA PIZARRAS’ Heavy 3 roofing slate.
Architecturally impressive, the roof plays a dominant role in the design of this contemporary Scottish home, which in fact won the Individual New Build or Small Development category at The Herald Property Awards for Scotland.
Providing a first-class defence against the elements, this warm roof construction also introduces rooflights and dormers, maximising space and light – both design priorities for the homeowners.
Featuring a simple continuous ridge along the house, the large roof expanse is punctuated by four tall chimneys, which, together with the stunning Alpine-inspired oversized roof overhangs, add real visual interest to the property.
Design architect and founding director at Thomas Robinson Architects, Fiona Robinson, explains more about the choice of roof finish: “The very nature of Scottish architecture lends itself to selecting a natural slate roof. Having used the CUPA PIZARRAS Heavy 3 slate on our own roof many years ago, as a practice, it’s our go-to slate of choice for projects that require a high quality and durable product. It also has a 100-year warranty on the slates, providing a sustainable choice for our client.
“The support from the company’s specification manager, Allan Liddell, is great too, from discussing initial proposals to working out the details, he’s always on-hand.”
A blue black slate with a slightly gritty texture, CUPA PIZARRAS Heavy 3 is produced in two thicknesses, 3.5mm and 7-8mm; the thicker variant being the preferred choice in Scotland with the extra thickness and weight giving it strength to withstand the high wind speeds and driving rain.
Fiona Robinson goes on to describe how the design for the house and its impressive roof came about: “There were several design drivers. Naturally, we wanted to be sympathetic to the surrounding Scottish landscape and local architectural style but also, the house previously on the site, which sadly was destroyed in a fire, was a lot smaller than our client wanted the new one to be. The challenge for us was to make the building appear as small as possible by keeping the footprint tight.
“To make best use of the site’s space, we followed the contours of the landscape. This gave us a softly curved c-shape for the five-bedroom house with two wings on the outside edge of the curve of the ‘c’. It actually looks like a boomerang from above. The large roof overhangs allow everything, including the garage, to be tucked underneath the ground floor. Built across eight different levels, some incredibly interesting spaces have been created internally. Making the most of the moorland views, we positioned the rooms to face north whilst to the rear of the property the two wings form a natural south-facing private courtyard.”
With a three-coat render system, called StoLotusan, forming the external envelope, builder Ian McDonald at Glasgow-based IMD Developments constructed the house traditionally.
The roofing element of the build has been backed-up throughout by CUPA PIZARRAS’ Specification Manager, Allan Liddell, as Ian McDonald qualifies: “One of the interesting parts of the project was detailing the large roof overhangs, which are timber clad to the underneath. We all worked closely with the engineer to mitigate the risk of wind uplift. A slater by trade, Allan knows the roofing business inside out and provides lots of good advice. His phenomenal knowledge has been a huge help, especially when it came to detailing the roof overhangs as well as the hips, ridges and lead fascia.”
Helping the building to achieve a good SAP rating, the warm roof installation, pitched at a 35° angle, comprises a steel-framed structure. Ian runs through the rest of the roofing specification, explaining: “We fixed 450mm-deep timber rafters and then built-up with a 400mm thickness of ROCKWOOL® insulation, a 50mm air gap and sarking boards. Compliant with Scottish building regulations, sarking is familiar to Scottish new builds and offers added strength and weather protection. Fixed beneath the Heavy 3 slate is a layer of Proctor Roofshield breather membrane.
“As the site is exposed to high winds, we took a real belt and braces approach to finishing the roof too, wrapping the leadwork under the fascia, which means there are no joins.
“Other details designed into the roof structure include multiple triple glazed Velux rooflights and stylish triple glazed Gaulhofer Fusionline wood-aluminium dormer windows adding light throughout. It certainly is a build to be proud of”, ends Ian.