Fastening wood column to steel beam
Fastening wood column to steel beam
(OP)
I am working on a project where a new hvac unit will be installed on a roof. The contractor would like to cut through the roof membrane and install 6x6 wood columns on top of the existing steel beams. An lvl would then be installed on top of the columns to support the hvac unit. What is the best way to fasten the 6x6 columns to the steel beam? Or would it be better to install steel columns and have the lvl's rest on top of the steel column? Thanks.






RE: Fastening wood column to steel beam
Simpson and others make a variety of clips that might work - Strong-tie.com
I guess you cold drill holes through the I-beam flange and lag screw the columns.
RE: Fastening wood column to steel beam
The 6x6 will only be about about 1'-2' tall. Are you saying lag screw through the flange into the bottom of the columns? I was thinking of using steel angles and bolting the angles thru the top of the flange and to the column. What do you think?
RE: Fastening wood column to steel beam
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Fastening wood column to steel beam
And your idea is OK by me. Mine might be cheaper - but if you only need a few - who cares. Just make sure any moments can transfer if need be.
RE: Fastening wood column to steel beam
Biggest issue may be thermal and moisture though. With steel columns they will be big thermal heatsinks to the interior of the building (depending on climate). With wood you need to seal and boot the wood to prevent water intrusion properly at the roof interface.
______________
MAP
RE: Fastening wood column to steel beam
RE: Fastening wood column to steel beam
The diagonal bracing would be OK too. Just have one omore area of roof penetration tyo deal with using the diagonal, and one more potential for a roof leak...
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Fastening wood column to steel beam
(1) The contractor doesn't want to weld to the existing roof beam
(2) The platform columns need knee braces and I have to elevate the platform more than intended (steps may be needed).
This is also assuming the existing framing can support the added loads.
Can you provide more specifics about the construction needs.
RE: Fastening wood column to steel beam
Will steel angles on all four sides f the columns be sufficient or do I need to elevate the unit to provide knee braces?
RE: Fastening wood column to steel beam
Is it acceptable to use wood as a structural member in this building? Check on the fire rating requirements.
By using steel columns (short stub columns) and perhaps rigidly welding to the existing roof beams, you might get by without any knee braces if you can laterally brace the supporting beams against the twist or bending in the columns. Essentially using vertical cantilevered columns as your lateral bracing system.
Also, for RTU's set above a roof, it sometimes makes a lot of sense to allow some space below for maintenance on the roofing materials in the future. We usually use at least 24" clear to allow access underneath.
RE: Fastening wood column to steel beam
Any suggestions or input? Thanks in advance.
RE: Fastening wood column to steel beam
RE: Fastening wood column to steel beam
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Fastening wood column to steel beam
RE: Fastening wood column to steel beam
RE: Fastening wood column to steel beam
Alternate would be to use a bent plate and bolt it to the top flange of the steel shape.
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com