John weren

Dan Parker wrote:If you extend one of the legs you may be able to fit  fasteners that will secure the rafter to the beam. Here I am showing a L8x6x3/8 with two additional screws or bolts with nuts.

Thanks!  That seat may work well at the girder truss to header joint, 3 ply/4.5” wide.

I guess could rotate the angles 90 degrees and add one to each side of the truss as well as per pic.

wrench weren wrote:

Dan Parker wrote:For the truss to header connection I would consider a piece of steel angle as a seat.

Depending on the diameter of the header, a size of steel angle with equal length legs could be specified. This approximately 8” long piece could be placed on the header with one leg oriented parallel to the truss or rafter to creat a seat.  Four holes in the angle could pass lag screws to secure it, two vertical screws and two horizontal.

Thanks for the thoughts.  Not sure I entirely follow.  Could you send a pic or do a basic sketch on phone?

. Header is anywhere from 6.5” to 7.5”

Dan Parker wrote:For the truss to header connection I would consider a piece of steel angle as a seat.

Depending on the diameter of the header, a size of steel angle with equal length legs could be specified. This approximately 8” long piece could be placed on the header with one leg oriented parallel to the truss or rafter to creat a seat.  Four holes in the angle could pass lag screws to secure it, two vertical screws and two horizontal.

Thanks for the thoughts.  Not sure I entirely follow.  Could you send a pic or do a basic sketch on phone?

Mike Haasl wrote:Wow, that is a funky shape!  Looks like you have some engineered plans, might they have specified a connection at the peak?  

The triple truss likely can hold the weight of the whole roof.  The other rafters just need to be solidly tied to the peak and the perimeter beam so they don't shear down into the building.  Normally with rafters you have to worry that snow load will push them down and blow out the walls of the house.  Here the truss is probably designed to hold them up (if connected well enough) and keep the wall beams from getting pushed outward.

All those words don't resolve the need for a very good connection between the rafters and the central truss.  

One thought could be to bolt through the vertical central 2x6 of the truss to add a block of wood (dark red) on either side.  Then the rafters (green) can rest on that block as well as be nailed/timberlocked to the truss.

Ya it’s shaped to conform to existing oval garden.
That’s a good thought with block and would be less obstructive than a longer board running in same place but from both edges of truss, but may exert excessive pressure on that piece of GTruss (may be overthinking it)  Would still be nice to tie the rafters to the GTruss for lateral movement, even though posts are solidly in the ground.

Yes the engineered drawings (for permit) specifically hurricane ties but not significant detail as was trying to save on cost

Mike Haasl wrote:So the bottom of the truss is flat and would be sitting on your round beams and you're wondering how to attach them?  

I would be tempted to just cut a small flat on the top of the beams.  Maybe 2-3" wide so they don't remove too much wood but give a flat spot for the truss to rest.  Then once the truss is sitting on them, toenail them in place or use some big hurricane ties to connect them.  I don't thing huge J bolts would be needed since they won't really want to move in any direction once the roof is on.  

Will you be doing one tripled up truss and then framing rafters radially from there to cover the rest of the building?  

Yes planned on making a small smooth flat surface about  1-1.5” deep on top of round beams and slight knotch in rafters to make smooth connection.  Tend to overbuild and was alsothinking the J bolts would look better that storm ties. Storm ties would wrap around the round beam and be visible.  Thoughts on the three ply girder truss sitting directly above the vertical pole, on the two connecting header beams?  Yes re rafters to G truss. I will add pic.  It’s a non symmetrical greenhouse.  Need to figure how best to connect the 4 rafters at the peak on each side of the girder truss. A hanger similar to pic probably works best but needs to be fabricated.

Hey there, I’m a newbie from western Canada and working on a greenhouse project.  I’m wondering how best to connect my girder truss and rafters to the round header beam?  I could use a J bolt if I offset the rafters a bit from the top of the vertical posts.  Not sure if it’s best to have the girder truss(3 ply) resting on the header beam and vertical post joint anyways?  Could fashion up some sort of metal bracket as well. Any thoughts would be greatly appreciated!
JW
Figured pics would help to explain easier

That’s great advice and I totally agree.  Just a matter of finding someone who specializes. I already have the poles and the fairly large span is what complicates things. Not locked into the reciprocal roof.  Just need something safe, looks good and reasonable cost.  

Hey there, would be curious to hear how this turned out?   I have a oval green house structure I need a roof for that has a diameter of about 30x25ft, and thought a reciprocal roof would be a great/natural choice!  I just failed to realize the span required and that 16ft length poles wouldnt do it.  Then I have to consider snow load etc.  So instead of winding it I have to get back to basics an ensure my ducks are in order.  Would be great to hear more about this project.  Regards

Hey there, my search for info on reciprocal roofs brought me to Permies.  Lots of great info and look forward to learning more and sharing what I can.  We recently moved to 5 acres and are expanding our garden.  feels like we've been gardening since we could walk but still feel like a newbie, there's so much to know and learn.  We have about 16 raised garden boxes, anywhere from 8x4 to 16x4 and are looking to add another 15, 3 x 8's, in a oval green house we are building. We've been setting up water harvesting as well....lots to do!  We are located in NW Calgary AB so our growing season can be shortened by our crazy weather....huge snowfall yestersay and today.  Hello to all and look forward to connecting!