Get the Big Picture on Roof Trusses

Get the Big Picture on Roof Trusses

By Oli James, Technical Director 

We are the market leader in timber engineering. As part of the James Donaldson and Sons Group, we have been in business since 1860 and over that time we’re continually at the forefront of innovation in timber engineering. We have developed a unique approach that offers a comprehensive, flexible service and the best value for your project.

We supply a full range of precision-engineered timber products, including roof trusses, panels, metal web joists and I-joists.

We are continually striving to improve our processes and products to give you the best, in the safest and most sustainable way. All our products are made using sustainably sourced timber, one of the most environmentally-sound standard building materials.

All our products are made to order and can be delivered in one delivery schedule, with one contact, guiding you every step of the way. Most suppliers will just quote for trusses, but we look at the bigger picture. When you require roof trusses, the cost doesn’t stop at just timber. That is why we offer three different packages and give you the option of a full specification.


We supply prefabricated Spandrel panels and Gable panels which eliminate blockwork at gables and party walls. The speed of build can help you get the building wind and watertight quicker, allowing follow-on trades earlier access to complete their work.

With attic roofs, this type of truss package includes chipboard flooring for the attic floor and plywood for the dormer cheeks. With areas of flat roof, it includes flat roof firrings and flat roof plywood.

Tilt Fillet is a multipurpose piece of timber that can be used for all types of building projects. The treated timber is ideal for use to fill gaps between joists connected at an angle or to add a slight pitch to a flat roof to allow water to run off. A firring is a piece of wood that has been cut along the full length diagonally. Firrings prevent a sharp corner from damaging the felt or membrane and allow water to run-off easily.



Mill Green Outlet Village is a brand-new McArthur Glen Designer Outlet based in Cannock, Staffordshire. The project consisted of eight large blocks covering an area of approximately 27,000m2, with all blocks constructed from steel portal frames split over multiple levels.

The design team at Ilkeston manufactured and supplied roof trusses for the project over an eight-month period with more than forty deliveries of trusses being made to the site.

The trusses were used to form the perimeter slopes on the blocks with allowances made for maintenance walkways and access to concrete flat roofs. There were also many decorative dormer roofs in the project, some of which were curved ‘eyebrow’ shaped, which were all included in DTE’s design and supply. The trusses required for the larger high-level duo roofs provided the focal points for the project.

"DTE has proven to be a reliable supplier throughout this project. The team delivered a quality product at various stages of the build process; producing high volumes of trusses when required. It’s been a pleasure working with DTE."

Tony Mitchell, Project Manager at Bowmer and Kirkland


Donaldson Timber Engineering designed and supplied the roof system for the renovation project at Kingussie Courthouse which was led by Morgan Sindalll. The roof system was comprised of standard roof trusses, glulaminated roof frames and columns. The existing listed building was to be converted into office space and an extension was also to be erected.

Roof trusses for the building were designed in-house and manufactured in Buckhaven by DTE. The development’s feature roof frames and columns were designed by The Gordon Farquharson Partnership and supplied by Kingston Craftsman. Both the standard and feature frames were required to plane through, as such accurate design and manufacturing were key elements of the project.

As the roof pitch was 50 degrees, the overall truss height fell above the transport height limit of four metres, and the trusses needed to be split into two parts. Due to a tight budget, the truss designer proposed a piggyback truss instead of utilising field splice plates. The glulaminated feature frames were supplied loose and assembled on site by Morgan Sindall.

"We provided a cost-saving solution by designing a piggyback truss, which is a standard design technique, but not one very commonly utilised. Although we weren’t supplying the entire roof structure, we do look at the project as a whole and endeavour to provide the most complete and cost-effective options for the customer.”"

Rodger Cook, Operations Director, DTE

By choosing DTE, you get a genuinely comprehensive timber engineering service that can save you time, money and hassle. When you order engineered timber products from us, we deliver precisely what you specify, from roof trusses to bare loose timber, through to a full package, with everything you need to get the job done right.

Why shop around when you could look at the bigger picture?