Glulam/Heavy Timber Connections

[GalileoG]

-What is the industry standard with respect to who is responsible for the design of heavy timber / glulam connections? The EOR or the steel fabricator? The company that I work for have always left the design of heavy timber connections to the steel fabricator / connection engineer - only showing schematically the type of connection and the required number of bolts - this seems odd to me, I have always detailed heavy timber connections in FULL as the EOR.

-Do you design and detail glulam beam connections (beam to beam, beam to column, etc...) as a fabricated assembly of steel plates or simply pick out a Simpson Strong-Tie connector from the catalogue? Which is typically done and when would one choose one over the other?

I am located in Canada if that matters at all.

Thank you!

 

[msquared48]

Could be an East coast - West coast thing, but I always call out the connection, whether it's Simpson, or specially designed. I specially design it only if it is not listed or made by Simpson.

Frankly, with some connections, you have to specially detail and design the connection to get the proper members to support the others, sometimes providing two or even three views - sometimes even an isometric.

Mike McCann
MMC Engineering

 

[dhengr]

GalileoG:
It seems to me that the EOR is responsible for these connection details, and all the more so when you start mixing materials. What the heck does a steel fabricator or detailer know about glue lams or heavy timber? Then, I’m not even sure if you can tell me if this stuff is really structural steel or misc. metal, so then who does this design and detailing. That fight will come up too. You designed the beams or trusses, who knows more about these members than you do, right then and there. So, do the connection details and be done with it. The number of bolts, spacing, edge and end distance, member size and grade are all in your domain and control while designing the member, so take the few extra steps and complete the process. You know how you want the connection to work, some third party doesn’t.

I used to do some of this kind of work for a glue lam supplier, where they got the job from an Arch. or contractor without any real structural design having been done, jest purty pitchers or ideas. I designed the beams, columns and connections for them. They detailed my connections and showed any of our special needs at masonry or steel bearings, etc. on their own shop drawings, and we furnished the whole package. Then they subed. the connection fab. out to one of the steel shops they worked with. I checked their shop drawings before they went out; crazy geometry, crazy cutting dimensions and cuts, hole and notch locations, etc. and the connections were fabed. right off our drawings.

 

[jayrod12]

We've done a few jobs here in Manitoba with heavy Glu-lam. The first time we detailed them and got asked if we would allow the glu-lam suppliers the opportunity to design and detail them. They were clunky looking but the client on that job didn't really care as long as they were cheaper (which they were).

There have been a few times where we have detailed the connections because the architects were looking for a specific type of connection (knife cut plates with only the bolt ends showing on the glu-lams.

So in the end it is up to the architect and client in our office, if they don't care how the connections look, we specify loads and get the glu-lam guys to design and detail the connections. If they care, we detail them.

 

[woodman88]

I have always done the connections for my trusses. If the client wants to hire someone else to provide a difference connection, at least I have a connection to show (and to show that I gave it to the client, of) what I said would work.

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.