Flashback 1996: Muscling in on Multiple Span Floor Joists!

This report by senior editor Jim Bowden in May 1996 focused on the benefits and major advantages of continuous span floor joists and bearers using the Musclebeam floor design system.

Wed 13 Dec 23


When builder Jeff Turner constructed his own 28-square home at Rowville in Victoria, the bearers and floor joists were laid in two days using a floor design that had two features different from standard practice.

“The first was continuous span floor joists and bearers using Musclebeam of 10 m lengths,” Turner said. “The second was using joist spacings at 600 mm centres to reduce the number of joists required.”

Turner said Musclebeam was so quick to lay when compared with other materials.

“One of the major advantages is that the 10 m lengths were so light (40-50 kg) they were easy to manipulate by myself.”

“Using long lengths, I did not have to worry about staggering joints and there was not a lot of wastage.”

The greater spans possible with continuous lengths enabled Turner to use only 34 stumps instead of the normal 90 to support the bearers, each of which had 3400 mm centres and spanned 1800 mm.

Turner doubled up 122 mm x 35 mm Musclebeam to form 70 mm widths for the bearer lengths and used 122 mm x 45 mm Musclebeam for the joists.

“Installing the Structaflor floor panels was easier and quicker – it took one day to lay – because the Musclebeam joists are much straighter than the alternative lapped joists,” Turner said.

“And nailing through the wraparound plates did not cause any major problems.”

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Markus Golinksi, Hasslacher group/Hess Timber, and Kieran Hayes, XLam, talk timber flooring with Kevin Ezard right) at Melbourne’s Timber Offsite Construction Conference and Exhibition (formerly FRAME Australia).

Musclebeam marketing director Kevin Ezard claims builders who use the Musclebeam Structaflor combination and change to 600 mm centres will substantially cut timber costs because they will reduce the number of joists by 25%.

“For the sub-floors or first-floor construction, the higher the lineal metre cost of the joist, the greater the saving,” Ezard said.

”Cost reductions won’t harm performance because the design stiffness of the joists selected for 600 mm centres gave the same result as those selected for conventional 450 mm centres.

“Fewer joists result in additional cost savings through fewer fixings and nails and less glue. Combined with long length Musclebeam of continuous span over two or more sections, it does not affect the stiffness of the floor.”

Jeff Turner said that when building his home, he had not compared the overall cost savings of Musclebeam with alternative materials.

“The biggest saving was in the time taken to do the job,” he said. “Because I was using long lengths, I had no worries about staggering joints, and there was not a lot of wastage.”

Turner said he had previously used Musclebeam in small quantities for window and door lintels but would now use it more extensively for future construction.

“My son Craig used Musclebeam to build his 40-square home and is very happy with it,” he said.

Turner said he was confident about the Musclebeam floor system design and believed he would unlikely have any maintenance problems.


  • Jim Bowden

    Jim Bowden, senior editor and co-publisher of Wood Central. Jim brings 50-plus years’ experience in agriculture and timber journalism. Since he founded Australian Timberman in 1977, he has been devoted to the forest industry – with a passion.


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