I want to build a green oak frame to form a covered area against a garden wall, with a lightweight roof. It will be approximately 8m long and 2.5m deep. Question - would it be best as two or three bays? Two bays would require less timber, as only one pair of intermediary posts, wind braces etc., but I worry that the top plate may be too cumbersome when raising the frame. I expect to use timbers probably 130mm x 130mm. I’ve not built with green oak before so my worries might be unfounded.
I would say three. Going to be tough to get an 8m piece I would expect.
Going to be hard to lift too. Isn’t an 8m piece in those dims going to sag?
What lightweight roof? Please dont use poly carb triwall, making that effort on the frame to put that on top would be a shame!😊
What lightweight roof? Please dont use poly carb triwall, making that effort on the frame to put that on top would be a shame!😊
What's the alternative for such a structure..... I'm planning a smaller scale similar build and was going for Tri wall polycarb.......
I've helped out on a few green oak and recycled oak frame buildings.
8m is a very long run, would be a line of friends to pick that weight up.
I suspect over that length you would also need to think about twisting and curving as it dries - more bracing is what we did on the building we worked on.
Whatever tools you use, expect to sharpen all of them again when using green oak.
The longest span is 4m not 8m.
Seems a little unnecessary to use a square timber though is that a green oak thing? You'd be better with deeper and thinner.
Try entering your dimensions into The Sagulator.
It's designed for shelving but can give you an idea at least....Maybe.
Thanks gents. I was planning on using 4m lengths for the top plates with a central join, it was 4m lengths I was concerned about lugging about - not just for the raising (as I can call mates round to help), but when needing to move about when jointing, practice fitting joints etc.
So I think my options were two bays using 4m top plates, joined above the central post, OR three bays with 2.75m top plates, joined above each of the posts. The latter will be easier to manipulate, but will require more timber for the extra posts and more time needed for a greater number of joints. I guess I could start my wife on a body-building course so she is more able to help……
Dad built a roughly 4m x 5m green oak barn / shed.
I don’t think you are but, Don’t underestimate the weight of it. Each section was weighty. Even moving it about to work on was hard work.
Cedar shingles for the roof.
Must be something in the air as I'm currently trying to spec/cost out a pergola for my new garden. For a corner pergola @ 4x4m @175mm posts in kit form the prices are ~£6k.... Out of curiosity has anyone ever used https://oaktimberstructures.co.uk/oak-pergolas/ ?
Build on the ground and raise it, Amish style
130mm x 130mm sounds small but IANAC
Thanks TheDTs, that was the reason behind my question, really. I’m basing the timber dimensions on those used in our green oak house extension. Whilst the main posts are 175mm square the intermediary posts are 140mm square and by my judgement would be more than big enough for what I have in mind. The current plan is for a lightweight corrugated roof or clay roof tiles, to be determined, on pine rafters, so I don’t think the loading certainly for the former would be great.
