With high winds in excess of 130mph prevalent on the Orkney Islands, a solution was required that could withstand these elements when it came to roofing a new facility for elderly and vulnerable members of the community. The BMI Redland Mini Stonewold Slate was chosen due to its strength, robustness and appearance of natural slate.
Hamnavoe House, commissioned by Orkney Islands Council (OIC) in order to meet the current and future needs of its elderly residents, was designed by Glasgow architects Young & Gault and built by Orkney Builders. The building represents one of the largest single timber kit buildings ever produced by timber frame provider Scotframe.
Designed as a single-storey property, to reduce its profile against high winds, the combination of flat and pitched roofs was designed to minimise gable heights and match local vernacular styles, as well as the ability to withstand extreme weather conditions.
The Redland Mini Stonewold Slate in grey was chosen by OIC for several reasons, explains OIC senior project officer John Wallace, who said: “The tile is very popular here and is popular with our planners. From the planners’ point of view, it has a flat slate appearance like many of our traditionally built roofs. It’s also very strong, especially when fully fixed, which makes it the perfect choice given our environmental conditions.”
This view is reinforced by Stephen Kemp, managing director of Orkney Builders. “These islands must be one of the largest purchasers of this particular tile,” he said. “It’s specified because it doesn’t fail. We recently handed over a newbuild house where gusts of 135mph were recorded, yet we didn’t lose a single tile.
“This is the biggest roof that we have installed in recent years, but it is a product that we know very well. We double nail and clip each tile as a matter of course up here, and always to the maximum headlap.”
The Mini Stonewold range has interlocking edges to simplify installation, and can be laid at pitches as low as 17.5° in both newbuild and refurbishment projects. The tile’s robust performance reflects the company’s extensive testing regime, which includes a wind tunnel that uses different combinations of high wind and driving rain to determine the tile performance in terms of wind loading and weather tightness.
Seven colours are available: Black, Breckland brown, Charcoal grey, Farmhouse Red, Slate grey, Terracotta and Tudor brown. As with all of BMI Redland’s slate range, the Mini Stonewold is fully compatible with a range of dry-fix fittings.