We use software from MiTek to design and manufacture Posi-Joists for residential and commercial projects.

These are very lightweight, yet strong metal web joists, which are suitable for use in both floors and roofs. With their open web design, Posi-Joists allow services to be installed quickly and with greater ease compared with more traditional solid timber joists.

Product features and specifications

Span greater distances

With a Posi-Joist, wide spans can be covered, bringing higher levels of design freedom.

Save time on installation

Posi-Joists are lightweight and easy to install, meaning you’ll spend less time on site.

Cut your project costs

Posi-Joist floors use fewer components than solid timber joists, saving you money.

Cost-effective solution


  • The span capabilities mean that these metal web joists can often allow for increased joist centres when compared to alternative systems, reducing the amount of material needed.
  • Joists are manufactured in a controlled offsite environment ensuring a quality product, and are delivered ‘made to measure’ allowing for speedy installation.
  • Using metal web joists often eliminates the need for load-bearing intermediate walls, which can dramatically cut overall building costs.

Flexible options for specification


  • The depth, length and width of these metal web joists can all be adjusted to produce an enormous number of different specifications, each with clearly defined performance criteria. In addition, end details of the joist can be altered to give a variety of support conditions.
  • Posi-Joists can include a trimmable end, incorporating a solid timber block which can be engineered to give up to 130mm allowance at each end for trimming on site.

Tell us about your project

David Smith St Ives design team

Speak to an expert

Adam Ding

We've worked with David Smith st Ives for a very long time. We need suppliers who can cope with our workload, and David Smith St Ives has plenty of capacity.

Kevin Dundas, Supply Chain Manager, Willmott Dixon

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