Pitched roof - hangers or bearer plate?

[Combover]

Hello all,

I'm currently designing a lean to roof for a lean to type extension and wondered if it would be easier to birds mouth the joists to a bearer plate of do a sort of inverted birds mouth and fit joist hangers into the brickwork.

Any help would be gratefully received!

 

[^woody^]

Sit them on a 50x100 timber bearer with m10 expansion bolts every 500mm

 

[Combover]

Sit them on a 50x100 timber bearer with m10 expansion bolts every 500mm

Thanks.

What sized joists am I looking at for roughly 3.5 m span?

 

[^woody^]

3.5m is borderline for 50x150 c16 timber at 400 centres - it depends on the actual pitch and tiles and if the "roughly 3.5m" is more or less than 3.5m.

You need to measure this more precisely as you may need a purlin if its more than 3.5m

 

[Combover]

Woody,

It's less than 3.5m I was going for 150 x 50 SW rafters @ 400 Centres, so looks like I will be ok.

I've allowed for birds mouthing the joists over the top of the bearer plate so they sit on top of it.

Roof pitch is low at 15 degrees.

Cheers