SpaceJoists are suitable to accommodate large services such as mechanical heat recovery systems.


Features and benefits:

  • Longer spans are achievable in comparison to solid timber. This may eliminate the need for intermediate load bearing internal walls, reducing a building’s overall cost.
  • Extra teeth improve SpaceJoist stiffness and strength which reduces deflection.
  • Burst-through holes increase web strength in compression.
  • Contacts tabs aid load transfer from webs to timber chords, increasing web capacity.
  • Manufactured to size eliminates site alterations saving time on site.
  • SpaceJoist can be designed top hung to eliminate the rim board in timber frame construction, improving air tightness and reducing thermal bridging.
  • SpaceJoist delivers outstanding acoustic performance to comfortably pass English and Welsh 40dB regulations. It even complies with the more stringent 43dB Scottish regulations without additional insulation, plasterboard or resilient bars. When tested with additional 100mm Rockwool insulation it achieves 44dB to meet Scottish Building Regulation Silver Standard.
  • SpaceJoist Category C open web floor solution is approved by the Structural Timber Association (STA) in their product paper 4 as an acceptable option to achieve a fire robust solution during the construction process.
  • Lightweight construction makes SpaceJoist easy to individually move on site without the need for crane hire. Alternatively, floor and roof sections (cassettes) can be delivered to site and craned into position to save build time.
  • Minimum chord width of 72mm.
  • Joists are manufactured off-site ensuring consistent quality and reliability.
  • Joists can accommodate large services such as mechanical heat recovery systems.
  • SpaceJoist can be incorporated into attic truss bottom chords to achieve greater spans, deeper insulation and provide a service void.

General information


Carbon steel




Width x length x depth.

38 x 72 x 195 mm

SpaceJoist TW8.

38 x 97 x 195 mm

SpaceJoist TW8.

38 x 122 x 195 mm

SpaceJoist TW8.

47 x 72 x 219 mm

SpaceJoist SJ9.

47 x 97 x 219 mm

SpaceJoist SJ9.

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One year

Uniclass 2015

Pr_20_85_90_11 Carbon steel lattice floor joists and purlinsPrimary

Specification data - Carbon steel lattice floor joists and purlins Enhanced data


Open metal web joist.



Overall depth (maximum)

195 mm.

SpaceJoist TWB.

219 mm.

SpaceJoist SJ9.

254 mm.

SpaceJoist SJ10.

304 mm.

SpaceJoist SJ12.

375 mm.

SpaceJoist TW14.

425 mm.

SpaceJoist TW16.

Product Reference

SpaceJoist TWB

SpaceJoist SJ9

SpaceJoist SJ10

SpaceJoist SJ12

SpaceJoist TW14

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Timber size.

47 x 72 mm.

47 x 97 mm.

47 x 122 mm.

Environmental information

Country of material origin

United Kingdom


Digital objects

Platform Compatible Version Certified to




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