Roof column onto deck

[JStructsteel]

Designing a deck with a roof structure, and the column is coming down to the deck below. Trying to figure best option to anchor the column. Have about 1200lbs vertical, and 1100 lbs uplift at the worst case.

Attached are two options, left, bearing on beam required below. Cant figure out a good base. Thought about the Simpson ECB, but they are pricey. Second option is bolted connection between the beam.

(2)-2x12 for the supporting beam, 6x6 column
[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1694366869/tips/Column_Base_x3woay.pdf[/url]

Anyone else got a good idea?

thanks

 

[JAE]

You could do either.
The left one may not have a standard Simpson column base you could use but you can always have one fabricated out of 1/4" steel plate to whatever dimensions you need.
Probably one with a horizontal base plate directly under the column with two side straps going up on each side of the column for through-bolts. Then have two steel tab plates extending down on each side of the lower support beam and weld them to the underside of the flat base plate.

Length and number of bolts as required for uplift and to meet NDS requirements.

 

[KootK]

It's the one on the left for me all day long. Gravity loads in bearing whenever possible it the way to go in my opinion.

 

[KootK]

An idea for the idea heap. SDS screws. These setups always make me nervous as I worry about how "survivable" the leftover post stub is at 2.5" wide. That said, you're already doing this at the low post.

 

[SWComposites]

with all of the deck failure issues out there, why would anyone cheap out on connection fitting hardware?

 

[JStructsteel]

Thanks, Yes I am leaning towards the left. Simpson makes a ECB (elevated column base) that keeps it up for water, and also gives me the uplift capacity.

If the contractor is wrapping the columns, I will more than likely just do straps and he can hide them.

KootK, I like the idea too of notching the column, would also give a bit of extra lateral capacity for what that is worth.

 

[Eng16080]

NO to Option B. Like KootK mentions, I would be worried about cross-grain shrinkage. Per NDS 2018, Section 12.5.1.3: "The perpendicular to grain distance between the outermost fasteners shall not exceed 5" unless special detailing is provided to accommodate cross-grain shrinkage of the wood member." Considering that the lumber will likely be wet PT when installed, I think that shrinkage is a real risk.

I would start with Option A and sister small 1.25" pieces to the double 2x12 to match the post width. From there, use some galvanized Simpson straps to connect the beam to the post, fastened with nails or wood screws, or steel plates with through bolts. If using bolts, keep the vertical spacing under 5".

I've also used the detail KootK shows above with the post notched. I usually try not to notch stuff though if there's another reasonable option.

 

[Eng16080]

Not to contradict what I just wrote, but based on your loads, I believe Option B would technically work with 2 through bolts located at mid-depth of the double 2x12. With the bolts side by side, that would eliminate the shrinkage issue with the beam.

That said, I still prefer to support gravity loads with direct bearing.

 

[JStructsteel]

Thanks all. This has come full circle. I think It will be the option KootK provided, notch the base of the column and have a bolted/screwed connection as needed.

Might have to sharpen my pencil on the wind loads, I was pretty conservative with the 1100lbs I stated.

 

[lexpatrie]

This looks like a guardrail attachment? Or is it actually like a post supporting a pergola above?

 

[JStructsteel]

@ Lexpatrie, its supporting a roof above.