SmartJoist – Uses & Common questions 

[ Approx. reading time: 2 minutes ]

Australia’s project and multi-residential builders continue to benefit from timber as a key construction material.  This practice is set to continue, with recent changes in building codes allowing builders to go higher than before (up to eight storey) with timber construction. Engineered Wood Products (EWP) enable builders to span further, build lighter, speed up build times and lower costs. 

SmartJoist is a range of engineered timber I-Joists for use in internal floor and roof systems.  The wide range gives builders the ability to choose the optimum – and most cost-effective – I-Joist for their floor system. SmartJoist exclusively offers a robust 255mm wet-area set down joist to complement the key 300mm floor joist sizes. 

Let’s have a look at some of the common questions asked about SmartJoist 

How far can SmartJoist span?

The span of a SmartJoist beam will be affected by the performance criteria a builder chooses to use for their floor system.  The SmartJoist Design Guide (you can download it from here) includes span tables for both AS 1720.3-2016 performance criteria (table 1), or the SmartJoist preferred dynamics EN 1995-1-1-2004 (table 2) which produces stiffer floors for those wanting a firmer feel in their timber floor.  Both tables list the MAXIMUM recommended joist spans, and therefore shorter spans in most cases should produce stiffer floors. Span tables are also provided for residential floors with ceramic tiles (table 3 and table 4) or SmartJoist as rafters (page 39). 

Can I have holes in SmartJoist?

Yes, you can!  SmartJoists can be drilled with large penetrations convenient for plumbing and electrical services.  All SmartJoist webs include a 40mm knock-out hole at 500mm centres for electricians to use for cables. The diagram below shows a general guide for larger holes. 

Builders can check what holes can be placed in SmartJoist in a number of ways: 

  • The SmartJoist Design Guide is available here to download – click here, and pages 31 – 33 provide detailed information and tables on hole/duct placement and sizes allowable.  
  • For basic holes, the Tilling ‘enhanced’ smartphone app has a section in its SmartFrame>Calculators specifically on SmartJoist Web Hole which can be used to verify proposed hole sizes and locations. 
  • For more complex hole combinations, or to verify, builders chat to NHS

For the ultimate in convenience, the SmartFrame Design Centre can design complete floor systems from engineering and architectural drawings with pre-cut service penetrations.   These floor solutions are provided to order, with rapid lead times.  To purchase SmartJoist products or arrange a design and quote, please contact your local NHS office.  

Contact us for any questions you have about this article – 4979 0000.