Knee brace connections for timber structures of picnic pavilion
Knee brace connections for timber structures of picnic pavilion
(OP)
We are designing the timber framing of a structure like picnic pavolin. we use post 8x8, beam 6x12 and knee brace 4x6. column spacing is about 15.5'. the knee brace connects column and beam.
The problem is that there is about 7 kip axial load in the knee brace (Dead load+snow load). What kind of connection can transfer 7 kip?
I was told not to use the mortise and tendon with pegs because of the cost. Nails, lag screws and bolts do not have much capacity.
Do we have some metal connectors (like joist hanger)?
I never design new timber structures before.
Any suggestions? thanks.
The problem is that there is about 7 kip axial load in the knee brace (Dead load+snow load). What kind of connection can transfer 7 kip?
I was told not to use the mortise and tendon with pegs because of the cost. Nails, lag screws and bolts do not have much capacity.
Do we have some metal connectors (like joist hanger)?
I never design new timber structures before.
Any suggestions? thanks.






RE: Knee brace connections for timber structures of picnic pavilion
RE: Knee brace connections for timber structures of picnic pavilion
Under wind load plus dead load, you may get tension in one of the knee braces. In that case, the entire force has to be resisted by the hardware.
BA
RE: Knee brace connections for timber structures of picnic pavilion
Mike McCann
MMC Engineering
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Motivation: Don't ask
RE: Knee brace connections for timber structures of picnic pavilion
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BA
RE: Knee brace connections for timber structures of picnic pavilion
These wood pavilions are nothing new, I'd try to make it work with classic methods first.
RE: Knee brace connections for timber structures of picnic pavilion
Actually, I can embed the timber post in concrete footing so the base can be modelled as fixed connection. in that case I do not even use the knee brace to make a lateral resistance system. but the knee brace make the frame looks good.
but if I did not put a strong enough connection, the knee brace may be pulled apart from beam during a big wind.
RE: Knee brace connections for timber structures of picnic pavilion
If you are going to embed them, add the knee braces for additional stiffness and looks
RE: Knee brace connections for timber structures of picnic pavilion
BA
RE: Knee brace connections for timber structures of picnic pavilion
RE: Knee brace connections for timber structures of picnic pavilion
RE: Knee brace connections for timber structures of picnic pavilion
Why not fabricate a steel bracket for the knee brace.
RE: Knee brace connections for timber structures of picnic pavilion
Have you got any more information on embedding using epoxy?
Wouldn't the timber soak water in that would run down and trap behind the epoxy?
We've recently just had to design repair solutions for two pole houses that had the poles embedded in concrete footings. One was only 5 years old and the 300mm diameter posts were around 70% rotted away. It would be hard to recommend even using your epoxy method in our region..
thanks
RE: Knee brace connections for timber structures of picnic pavilion
RE: Knee brace connections for timber structures of picnic pavilion
BA
RE: Knee brace connections for timber structures of picnic pavilion
RE: Knee brace connections for timber structures of picnic pavilion
RE: Knee brace connections for timber structures of picnic pavilion
BA
RE: Knee brace connections for timber structures of picnic pavilion
A 3/4" bolt and one 4" split ring will likely have sufficient capacity. It would be a much cleaner connection and is also fairly inexpensive compared to custom steel brackets.
RE: Knee brace connections for timber structures of picnic pavilion
I have seen these pavilions set on concrete piers that had T's bolted/embedded to the pier. There was a slot cut into the bottom of post and it was slid over the stem of 'T'. A hole was cross-drilled through the post and a pin inserted through those holes and a hole in the 'T'. It was quite clever.
Also, I think a proper construction sequence could eliminate some dead load in the knee braces. If the 6x12 beams can handle the dead load without large deflections the knee braces could added last, thereby reducing the dead load in the bracing....of course over time the knee braces may see more dead load as the structure settles/moves.
RE: Knee brace connections for timber structures of picnic pavilion
BA