Ochil’s curved trusses on Tiree

Over the last three years, Denny-based Ochil Timber has been part of an intriguing architectural project on the island of Tiree.

The build has seen the construction of two spacious family homes and the extension of another, each featuring a unique curved roof designed with Alpine CAD engineering software by ITW Construction Products.

The homes were all constructed by Cornerstone Construction Scotland Ltd, which specialises in one-off homes, often in remote locations.

Jocky Bryce of Cornerstone, who now lives on Tiree himself, describes the project as “an opportunity to build efficient modern homes in a style which pays homage to some of the traditional architecture you find on Scottish islands.”

He added:

“The use of curved roofs in this part of the world is a direct response to the weather conditions you get here, to the exposed nature of sites and the wind speeds that buildings have to withstand. Traditionally the roof trusses would all have been hand–made, but by using prefabricated trusses we saved several man hours on each job.”

Ochil Timber, which specialises in the offsite fabrication of innovative engineered timber components for roofs, floors and walls, supplied the timber trusses for all three curved roofs.

Andrew McAree, MD of Ochil, admits that the non-standard nature of the roofs presented some challenges. He explained:

“Usually people think trussed roof rafters are all about angles. This proves pre-fabricated trusses can be used for many different shapes, including curves. By plotting the exact placement of the joints on the trusses we were able to deliver a perfect curve on the external surface of the finished roof.”

Chris Hannah, designer of the trusses commented:

“I was impressed to find the Alpine software coped perfectly with the unusual roof shape in applying loadings and designing tricky cuts. Knowing Alpine technical support was available for assistance whenever required, meant I had complete confidence in the design. The software output to our CNC saw meant that manufacture also went without a hitch.”

In addition, it was important that the internal spaces and dimensions of the dwellings as envisaged by the architects were maintained, and the use of attic trusses by Ochil ensured that usable “room in the roof” space could be included.

Once the trusses were erected, a process which Mr Bryce says went “Perfectly, no problems whatsoever”, the roofs were finished with sarking, felt and several layers of Evopaste and scrim, ensuring they were entirely weatherproof. All three houses are now complete, providing thoroughly modern homes which also fit perfectly with island traditions.

Over the course of the project Ochil supplied 56 trusses to Tiree, all of which were manufactured in their Denny factory from sustainably–sourced timber.

Ochil Timber Products’ experienced team are on hand to manufacture roofs of a standard shape to the more unusual – and can be contacted on 01324 825503 (admin(Replace this parenthesis with the @ sign)ochiltimber.com) to discuss your requirements. Alpine roof truss system suppliers, ITW Construction Products, can be contacted on 01592 771132 for enquiries.