Hi All,
I'm planning to build a small/medium free standing timber frame pavilion and would like to get design recommendations from the ask the experts forum.

The size I'm considering is anywhere in the range of 12' X 16' up to perhaps 16' X 24'. I have access to 16' white oak timbers, anything beyond 16' is difficult to obtain/handle/expensive or would require scarf joints.

So, if you were designing a 12' X 16' pavilion what would you do? How about if it was 16' X 24'? What kind of roof structure? English tying joints or dropped tie? Any nice examples you are aware of?
Thanks,
Chip

The Guild has built a few variations on an Ed Levin design that is quite nice. I helped with the iteration at Effinger School in Lexington, VA. I believe it has been done at least three other times; each a little differently. Pictures are still on the Guild's web page.

Bob

Hi, I'm familiar with the Ed Levin pavilion design, it is indeed a nice frame. The structure uses kingpost trusses, roof purlins, tapered posts, english tying joints.

I am most likely looking at something with just four posts, and a size of perhaps 16' X 16'.

I'm thinking along the lines of a dropped tie beam common rafter structure, with a ridge plate connected to the center of the tie beams with a vertical strut. Braces would also be installed from the vertical strut to the ridge plate (is it called a purlin?).

The ridge plate will eliminate the roof thrust and distribute the roof load equally to the two tie beams (point loads) and the two wall plates (distributed loads).

I believe that the ridge plate would see the largest load and should perhaps be an 8" X 10" with other members being 8" X 8".

What arrangement/joint would you recommend for the rafter pairs meeting on top of the ridge plate? I know that John Milburn is using the step lap joint at both the upper and lower ends of his shed roof rafters.

Any comments or other suggestions?
Thanks,
Chip

hi Pillar:
Just a note here for the good of the order (so they say).
You probably know by now I refer back to historic examples of buildings like the one you are going to construct, which is a very basic small structure. I must say that of all the examples I have seen up here in Upper Canada, never have i came across one with a ridge timber used like you are describing. It seems alittle bit to me like overkill, the rafters need not to be supported in the fashion you are describing, but rather just half lapped at the top, and set in nice mortises on the plate and pinned there..
the Tie beams will easily hold the outward thrust of the rafters, as long as they are well mortised and tenoned and pinned with (2) oak pins (1.25" diam) at each attachment point.
Im not saying not to do it, but why do something unecessary. You can't go wrong following old methods in my book
NH

Thanks for the response NH.
This isn't the first and certainly won't be the last time I will be accused of taking an "overkill" approach to something!

Part of my concern here is that a 16' bent spacing is rather large, at least for me. I may need to reduce this or add a bent.

The other issue is that I was considering a relatively shallow roof pitch, perhaps 4:12 or 6:12. I would like to keep the overall height of the structure low, I do not plan for any loft area. The low pitch roof will also increase the roof thrust.

To use a more traditional design would probably require increasing the roof pitch.
-Chip