
Roof Trusses, Attic Trusses & Posi-Joists
If you're planning a project that involves roof trusses or Posi-Joists, considering the feasibility of a trussed roof, or exploring the advantages of metal web joists, we offer design, manufacturing, and delivery in as little as five working days. With nearing two decades of experience, a state-of-the-art facility and some of the best designers in the industry, you can trust Tailor Made Designs to be a reliable partner throughout the process.
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Fink
Simple, quick and cost-effective, the fink truss is a staple choice for simpler builds or ones working to a budget.
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Attic
Utilising what would otherwise be wasted space, the humble attic truss is our favourite option for almost every project.
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Raised Tie
Popular in garages and upper floors, the raised tie adds a touch of interest to any room with the practical benefit of some extra headroom.
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Scissor
Costing roughly the same as a fink truss yet adding bags of character thanks to its vaulted ceiling, the scissor truss is an underrated option.
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Mono
Ideal for sheds, extensions, garages or simply as an element within your overall design in combination with other truss types.

Free Guidance
If you're in the initial stages of design, reach out to us and one of our experienced designers can provide expert guidance on the feasibility of incorporating a trussed roof into your project. As an example of what can be done, have a look at one of our recent projects below.
Explore one of our designs ⤵
Posi-Joist documents
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The World of Roof Technology
ViewThis comprehensive guide to trussed rafters includes and roof truss framing includes information for specifiers, technical information on trusses and information for safe handling of trusses on site.
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Guide to Attic Trusses
ViewThe ‘Room-in-Roof’ (‘RiR’) or attic truss is a simple means of providing the structural roof and floor in the same component.
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The benefits of Posi-Joists
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Strength 💪
Thanks to the clever combination of timber and steel in their design, Posi-Joists can span greater distances than solid timber, reducing or even eliminating the need for load-bearing walls or steel beams.
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Service Routing 🚽
Thanks to their open-web structure, Posi-Joists can accommodate various services without modification. With MVHR becoming all the more common, this is a huge benefit to both installer and customer.
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Ease of installation 🔨
Posi-Joists are manufactured to the size of the building and can be simply dropped into place. If the building isn't perfectly straight, Posi-Joists can be supplied with trimmable ends.
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Weight 🏋️♂️
Posi-Joists use less material to achieve the same strength as solid timber, making them significantly lighter and easier to handle.
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Quality ✏️
Posi-Joists are designed in specialist software and produced under factory-controlled conditions, ensuring an unmatched level of quality every time.
Posi-Joist Span Table
Available Configurations
Depth (mm) | Joist Width (mm) | Centres (mm) | Max Span (mm) |
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Useful documents
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The World of Posi Technology
ViewThis comprehensive guide to all things Posi includes standard details for masonry and timber frame construction, installation guidance, information on acoustic and fire performance and much more.
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Posi-Joist Brochure
ViewThis brochure provides a general overview of the product outlining the many advantages of specifying Posi-Joist.
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Posi-Joist Acoustic Test Report
ViewFull acoustic test report for different Posi-Joist floor makeups detailing Posi-Joist’s different acoustic performances in different situations.
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Posi-Joist Standard Details
ViewA comprehensive set of Posi-Joist standard details including masonry and timber frame details.
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Posi-Joist Installation Guide
ViewA pictorial guide to best installation practice, including detailed written installation instructions and useful Do’s and Don’ts
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Benefits of Posi-Joists
ViewConstructed of kiln dried stress graded timber and plated together with high strength steel webs, metal web floor systems have a number of benefits compared with other floor and joist systems.
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Posi-Joist Fire Summary
ViewThis document details the extensive programme of fire tests that MiTek has undertaken in order to provide a range of compliant floor build ups for 30, 60 and 90 minutes fire resistance to EN Standards.