metal web roofs spacejoist spacejoists - metal web services
metal web roofs


David Smith St Ives is a leading supplier of Spacejoist® products. All our metal web solutions are engineered using the advanced Gang-Nail® system software. Our modern on-site manufacturing facility, plus our own timber treatment plant, gives us the flexibility to react quickly to our customer’s needs, delivering a complete floor or roof system to suit your requirement and specification.

Our highly experienced design team, using leading edge computer software, produce detailed structural design drawings and calculations for your project. Utilising our expertise, we can help make cost-savings where possible, and solve complex design challenges.

Spacejoist® are constructed from two parallel stress graded timber flanges connected to the patented V shaped galvanised metal web. The unique metal web design offers increased stiffness and better performance in compression when tested against the markets leading competitors.

design flexibility

The use of metal web floor systems has grown significantly in the UK, with engineered joists replacing both traditional solid timber joists and concrete flooring. Metal web joists improve construction efficiency by reducing installation time, producing less site waste and providing long term stability. Metal web joists are simple to set out and install and, crucially allow for services to run virtually unimpeded within the floor zone.

open web design

The open web design allows for greater design freedom when planning for services due to an easier more practical installation solution. Additionally no drilling or hole locating is necessary, which reduces the possibilities of incorrect workmanship, saving valuable time on site for the service engineers and reducing labour costs.

servicing zones

metal web apeture details
Depth D* H* W* S* X Y
120 73 208 107 605 125
120 73 208 107 605 125
154 97 208 133 605 159
192 121 215 155 605 210
265 178 264 212 705 330

* These dimensions include a 3mm clearance. These are approximate as
discrepancies may occur in manufacture.


Greater clear spans give potential to omit internal load-bearing walls that would be required for traditional solid timber joists. Spacejoist® are suitable for use in ground floor applications and a variety of end support details such as “top chord supported” can be provided. Spacejoist® are also perfect for roofing applications, their inherent strength means they are highly competitive against other timber products or steel. With spans available in excess of 12 metres, Spacejoist® are ideal for flat, low or steep.

spacejoist® features

Spacejoist® offer an excellent alternative to both traditional joists and I-beams. The key benefits being:

light weight

With smaller timber sections and the light weight metal web, Spacejoist® as a finished product is lighter than its timber equivalents. This gives greater handling possibilities on-site.


The speed of setting out of joists on site is increased due to a larger bearing surface, which in turn improves joist stability and enables easier fixing of decking materials. Fixing times are also greatly reduced as the floors are made to measure and supplied with clearly detailed layout drawings.

long term stability

Spacejoist® beams are dimensionally stable. Cross-grain shrinkage is kept to a minimum due to the smaller timber sections used in the design, and this in turn leads to quieter longer lasting floors.

improved sound and vibration.

Spacejoist® SJ10 (254mm deep) offer outstanding acoustic performance and meet the minimum requirements for sound resistance in intermediate floors in England, Wales and Scotland without the need for insulation, resilient bars or additional insulation.

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David Smith St Ives Limited
Marley Road
St Ives
PE27 3EX
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