On 7 Nov 2005 02:46:13 -0800, wrote:

I have a shallow pitch roof design that involves 225mm timber purlins
supporting 50mm counter-battens, then battens and interlocking concrete
tiles. Span of purlins is 4 metres. (Insulation between purlins based
in knauf insulation examples). Then purlins were to be hung from
masonry using joist hangers.
What could I replace the timber with in order to make the roof thinner
? I have no experience with composite beams etc.
Cheers,
Simon.

Steel

Do you mean purins or rafters ?

Steel must be boxed in. You need to go back to the engineer and ask
him to recaculate. The extra weight may effect him, and he can advise
what size you need. Or simply go back and ask if the roof can be done
thinner.

Rick