Afternoon All. Apologies for my delayed replies. I thought I had notifications set to tell me when someone replied. It seems I did not!
@Temp I would like to keep the garden side roof height as high as possible, so I don't bang my head and also restrict light into the property. It is quite deep at its deepest, ~4.4m, so any pitch has a big impact on this height. Height of the roof at the back wall of the house will be ~ 2.9m (topside) I am not keen on a flat roof, as the coverings are never pretty. So I was thinking as shallow as possible to get away with a pantile style tile. Something in the region of 5deg. Less than the minimum prescribed pitch, but given its an outside seating area (i.e. not a weatherproof habitable space), it doesn't need to be watertight as such, and building control might allow it. If it does need to be watertight, was thinking the same, but with some EPDM (or similar) beneath the tile to act as the watertight layer, and the tile on top for cosmetic.
Open to suggestions though. Just want it to look nice and fit with the traditional style of the structure/house.
@Alan Ambrose Yes there will be a roof. The only reason to build it is to have somewhere to sit in the glaring sun/rain. I was thinking mortice and tenon for the main joints. Is there a standard size for the mortice for a given beam size? Would the same go for the knee braces into the upright and beams? If I do put a shallow pitch on the roof, then birdsmouth would probably be the way to go for the rafters I think. And yes, the plan is to have small brick pillars ~5/6 courses high with a chamfered pillar on top, for the main upright posts to sit on.
Any suggestions on how to finish the structure on the LH and RH property boundary? If there are 4 upright posts with a main lateral beam, would you just run the rafters from the back wall of the house to the lateral full width? Or have something different on the outer most edges?