Timber engineering is often used for projects where steel is too expensive or environmentally unfriendly. This was the case for a recent project where the client wanted a large, open attic space without any vertical posts or large steel structures.
Gemma Weston, a truss designer with 20 years of experience, was tasked with designing a roof that would avoid using cranked steelwork and maximize the attic space. She came up with a solution that shows how expert technical knowledge and creativity can be used to solve problems and meet client requirements. Her design won the Residential Project of the Year award at the 2023 TRA Roofscape Design Awards.
Gemma’s solution used only one steel beam, which was hidden within the attic floor joists. She used various Cullen JHI masonry hangers and load-bearing walls to support the bottom chords of the trusses. The roof featured a tiled finish and a complex design that involved intersecting gables and a hipped crown top roof overlay, which optimized the internal usable space.
Gemma’s design incorporated a combination of cranked special monos with collars and flat-top roof rafters, as well as flat-top attic trusses that were webbed out within the room verticals to enhance truss strength.
During the design process, the client requested some adjustments, such as increasing the size of the roof lantern within the flat roof area and altering doorway positions to suit their desired room layout. Gemma was able to accommodate these changes without compromising the overall design.
The attic space was used to create four bedrooms, two ensuite bathrooms, and a family bathroom. The entire structure was interconnected to ensure stability. Flat parallel trusses were employed to form ridges in open spaces, supporting loose rafters and raised tie monos.
Once the roof design was finalized, the engineer reviewed all calculations and provided the exact size of the steel required to ensure safety and technical compliance. Minor adjustments were made to ensure seamless integration between the lengths of the steel and other metalwork components.
According to the TRA Roofscape Design Awards judges, Gemma’s design was “a solution that utilised all of the designer’s know-how and systems software features to create a habitable roof space to exceed the client’s requirements. A great residential project showing the potential of attic trusses. Complex and challenging design with raised collars, a flat roof section, and minimal internal support.”
Gemma said: “I enjoyed working on this project, as it allowed me to use a variety of methods and experience to help the client achieve what they wanted.
“Winning the award meant a lot to me as it provided recognition for my years of designing complex roofs.
“I would encourage anyone to become a roof designer. I am a woman in a male-dominated industry, but this is the best career move that I have made. The attention to detail that can be required in this job requires someone with design flare and who is not to be afraid to give things a try.”