purlins in aircrete

[sm_jamieson]

Is it OK for the regs to build roof purlins into the inner aircrete skin of a cavity wall ? (cold bridging etc) Can they rest on the aircrete blocks without any padstone ? I have to support purlins near the top of such a wall, and hangers usually need a weight of masonry above. I cannot think of any other way of getting a good support with the lightweight blocks. If it was rafters, a wall plate would be used, but the wall is sloping, so this would not be suitable. Also, can the aircrete blocks be cut height-wise to support the purlins at the correct height ? Thanks, Simon.

[Newshound]

Can you have a purlin at the bottom of a rafter? Or is this like a sleeper wall which comes part way up the rafter? Either way, it sounds more like a wall-plate to me.

[sm_jamieson]

the regs to build roof purlins into the inner aircrete

I have several purlins supporting thin 47mm rafters (called counter- battens on the plan). The purlins are where they would usually be, at right angles to the rafters, and at various positions up the roof slope. In every house I have lived in, purlins in the loft have been built into the wall, but I have never lived in a "new" house with aircrete inner leaf. The question is about building purlins into an aircrete inner leaf in this way, to current regs. I guess most modern houses have trussed roofs and no purlins. Simon.