By providing stronger, well-engineered rafters and joists that can be easily joined in one unit, prefabricated trusses have changed roof framing.
The truss is the roof’s frame, and it is designed to support and strengthen the roof. These bridges are arranged at regular intervals above rooms, with longitudinal posts supporting them. Their purpose is to ensure that the roof stays intact through their triangular wooden structures.
There are many variations of timber roof trusses to choose from and they all have their own strengths and benefits. So which roof trusses are the strongest option for your construction project?
What makes a roof truss strong?
The design of roof trusses makes them stronger than any other arrangement of structural elements in your roof because they can stand up to much larger forces of tension and compression. It doesn’t matter what material you use, timber for example is extremely strong when assembled into a prefabricated roof truss.
When a roof is supported by roof trusses, it is both healthy and functional. That means a roof is able to properly reflect UV rays and ward off condensation and mould.
What are the different designs and which is the strongest?
Trusses come in various strengths, but the one that is most appropriate for a particular application will be the strongest. Truss designs fall into five basic categories: dropped chord, raised chord, parallel chord, raised heel and scissors.
Raised chords: The benefits of raising the truss higher are twofold, it simplifies attic ventilation and it leaves sufficient space above the exterior wall top plates for insulation. This is the most common form of roof truss used in housing.
Dropped chords: With the dropped chord variant, a conventional truss is topped with a second chord truss to minimise uplift. This type of truss creates a vapour barrier similar to the raised heel truss, providing great insulation properties. In the intersection of walls and ceilings, vapour barriers require additional blocking and siding, which increases construction costs.
Parallel chords: Due to the use of steel members, the cost of this design is higher. High ceiling buildings employ the design, like cathedrals, because it is durable and reliable. Because this design uses steel members, there is thermal bridging, which makes it less energy efficient. It is aesthetically pleasing due to its parallel placement of members.
Raised heel: When you are looking for an energy-efficient truss design, a raised heel is an excellent option. The members of a truss design are arranged in such a way that they create a vapour barrier that eliminates condensation problems in humid areas. Due to the truss’ insulation, that does increase the cost, but the members are also protected from the environment. This design is commonly used in houses and buildings with attic space.
Scissor: Vaulted ceilings often feature this design. As the trusses provide plenty of support, no bare beams are needed with this design. The scissor roof truss gets its name from the way its members slope inward as if they were scissors. This design is difficult to insulate.
All truss designs provide a sturdy foundation for the roof, so it is difficult to determine which is the strongest. Trusses have been tested and improved for years so it all comes down to which option is best for your application.
If you would like to learn more about roof trusses and which solution is best for your construction project, contact us for a fast quote.
We can provide quotes, budgets, and advice, so please contact us today on (02) 4351 2616 and speak to one of our experts. You can also visit us at www.heydenframeandtruss.com.au, if you need additional information about our products and services.
We service the regions of Sydney, Gosford, Newcastle, Central Coast, and surrounding areas.