On 14 Dec, 13:12, dg wrote:
On 14 Dec, 12:39, sm_jamieson wrote:

Trying to think outside the box.
I have plenty of headroom in the loft. What sized timber I beam would
I need to use instead of the typical RSJ to support the ridge ? Loft
size 5.5m x 7.5m, normal cut roof with purlins at 1/3 and 2/3 heights,
V onto spine wall at purlin mid point, clay tiles etc.
Thanks,
Simon.

How do you know you need a ridge beam? Rafters are self-supporting and
there may be little or no load at the ridge

dg

Sorry, I didn't say - there will be a dormer on one side.
I do wonder about lateral forces in this situation - maybe a thin
timber I beam would not be suitable.
Simon.