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I-joists present a very practical and cost effective alternative to a concrete floor. They are an extremely stable flooring solution, helping to eliminate squeaks, shrinkage and snagging.

An I-Joist is a composite engineered timber joist, combining 45mm deep high-grade finger jointed softwood flanges (C24) with a 9mm thick oriented strand board (OSB/3) web. Four flange widths are available at 47, 63, 72 and 97mm wide.

These materials have different specific properties and by combining the two materials in this way to form a composite section you can use the strengths of each one where it is needed most. This results in the new section outperforming the individual materials that it is made from (the sum is greater than its parts) making it more structurally efficient. Using advanced technology these components are combined to produce an innovative alternative to conventional construction timber with many additional advantages.

Timber I-Joists available from Haldane Fisher

I-Joists are designed to give a superior strength to weight ratio enabling the manufacture of longer and lighter structural members.

They are also:

Much Faster to install than traditional Joists

  • Lighter and longer
  • Made to measure - no site wastage
  • Easier to install plumbing and electrics
  • No requirements for mid-span noggins or herringbone struts



  • Longer spans achievable reducing or eliminating the need for intermediate support walls
  • Opportunity to improve floor quality
  • Retro installation of additional services with minimum of disruption


Reduced Building Maintenance

  • No Shrinkage
  • Less squeaks and creaks
  • Less building movement
  • Stiffness and strength built into the floors improving floor rigidity


Cost Effective

  • Despite the higher material cost, reduced overall build cost
  • I-Joists sizes are compatible with those of solid joists - no need for expensive drawing changes.