Extending Bearing for Oak Purlin

[switch33859]

Good Evening All

I am currently designing the roof structure of an extension I'm starting. The extension will be a timber frame (140mmx38mm panels stick built). The roof structure will be an oak rafter/purlin construction that will be left exposed under a warm roof.

Two bedrooms side by side with a 140mm dividing wall. Each of the purlins will sit on an external timber wall and this central dividing wall. As the external wall will only be carrying one purlin at that location achieving the minimum 80mm bearing will be possible. However at the locations purlins sit on the central wall, it will have to to take the purlin from each room (end on end) and therefore only be able to achieve 70mm bearing.

I would ideally like to achieve 100mm bearing for each purlin. Does anyone know a standard bearing extender that can sit on this central wall and extend the bearing available from a 140mm timber wall to minimum of 200mm?

Would prefer not to offset purlins as the roof slope is quite small so would look lopsided in the rooms.

Thanks in advance.
Dave

 

[screamer]

can you lap them?, so one is 50mm out of line of the other one?
if they're in different rooms no one will see they're not fully in line with each other

also, if you're kit panels that are 140x38, is that the norm nom?
I'm always used to 50mm thick (45 reg)

 

[Deleted member 174758]

Have you considered using something like a steel angle bracket or brackets? These can be cut and made up from 150 x 150 angle steel (4 to 10mm thick) with holes drilled through to take bolts connecting the two together through a wall and also to connect the purlin ends to the angle plates (may require a top fish plate). I have used this type of solution on larger section timbers on refurbs. An S/E should be able to advise