Wrap Steel I-beam with Logs?

[Big Jilm]

Hello All,

I was curious if there some suggestions for wrapping 10-12" I-Beams with 12-14" logs. I am replacing an existing exterior deck structure that is currently made out of logs and failing. We have opted to replace it with a steel skeleton and wrap it with logs to re-create the original appearance. I was thinking about attaching threaded rod to the bottom, routing out the logs in a rectangular U shape and coming up from underneath and screwing on. I am in the initial phases of design, and wondered if there were any suggestions from the forum. I may be possible to substitute HSS for W section, however, I had originally selected the W for flexibility as the deck section is not yet finalized.

Mike

 

[msquared48]

Seems to me that you will need a 16" diameter log to develop the U shape for either a W10 or W12, considering the clear distance from the edge of the flange to the outside of the log. I would like to have a minimum of 2", or better there.

You should also fill in between the flanges and bolt that through the W shape. Then you could lag screw and plug the log section to the infill.

Mike McCann
MMC Engineering

 

[Big Jilm]

Thanks Mike,

I had not gotten down to the specifics of the log sizes yet but appreciate the clear distance guideline. I like your suggestions, perhaps the log guys could then use 2 half logs lagged into this infill piece. as opposed to trying to rout out a whole log.

I appreciate it,

Mike

 

[racookpe1978]

A WT shape would be easier to "slide on" than the large flanges of a true WF.

Obviously, you'd lose the strength of the twin WF flanges, but if you could use a heavier T (thicker webb, longer webb) to make up the loss of that flange, you probably would find the total package easier to work with.

 

[dhengr]

Let’s see some plans, elevations and details, otherwise we are just guessing at what you are trying to do. 12 or 14" dia. logs will span a fair distance and carry a fair load, and the deck worked for years as a log structure. And, now you need 10 or 12" WF beams for the new deck. That must be one heck of a new deck, and you’ve added the complexity of two materials and of the joinery around them. And, you still have logs which must have the joinery water sealed and preservative treated. What are you gaining here? Why not spend the same money doing a good job of detailing a reasonable log structure?

 

[racookpe1978]

True, we are all guessing at the original construction, but I'm thinking that my original thought of a WT is harder than a simpler/cheaper/stronger rectangular tube steel member. Then, notch the log with a simple "U" out out of the top of the log with a chainsaw and adze, slide the log over the TS member from below, and fasten the log outline to the TS member.

The log has no visible joints or cuts longitudinally.