On Jul 3, 10:52 pm, "Newshound" wrote:
"sm_jamieson" wrote in message

oups.com... 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.

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.

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.