tube/i beam buried vs bolted?

[fordguy]

I need to put up some lights about 20' up in the air, as well as some shade space to work on stuff.

I see some bury/cement it direct in the ground, others make concrete base and bolt the tube/beam to it

Is one way much better than the other? I am seeing it as bury and pour concrete into the hole a quicker job, versus digging a larger hole and pouring a bse with some J bolts and attaching the tube/beam to that.

Any input aside from that?

Thanks

 

[CarterKraft]

I need to put up some lights about 20' up in the air, as well as some shade space to work on stuff.

I see some bury/cement it direct in the ground, others make concrete base and bolt the tube/beam to it

Is one way much better than the other? I am seeing it as bury and pour concrete into the hole a quicker job, versus digging a larger hole and pouring a bse with some J bolts and attaching the tube/beam to that.

Any input aside from that?

Thanks

However you want it.
I usually pour footings with weld plates because I like the freedom of adjusting the post.
Also the length of the post + the depth of the embedment can cause you to have to buy much longer posts than needed.

No need for a bolted connection at l if you are fabbing on site, that's for a "no weld" type structure.

 

[fordguy]

However you want it.
I usually pour footings with weld plates because I like the freedom of adjusting the post.

this thing?

 

[CarterKraft]

this thing?

Yep, some will have nelson studs but same thing.

I have made my own with plate and bolts, rebar etc. but they are usually cheap to buy.

 

[PAToyota]

Also the length of the post + the depth of the embedment can cause you to have to buy much longer posts than needed.

OP, you say you're putting things 20' up in the air. Most places sell 20'~22' sticks of stuff, so you're looking at longer pieces if you're going to bury 4'~6' of it.

 

[[486]]

rebar in the footings is cheaper than I beam if you're buying both brand new

 

[CarterKraft]

Here's my RV storage bay. Poured footings with rebar cages and weld plates.
That gave me the "brick ledge" and a start of a frame to form up the footings to make the perimeter.

 

[fordguy]

Nice footings! Specs? Depth rebar or no? Nice concrete work, doing it yourself?

Specs on the posts??

 

[AlxJ64]

If you choose to weld studs to a plate or such, make sure you get the weldable type rebar or go with nelson studs like CarterKraft did. Your generic rebar from Lowes and HD are not rated for welding - sure bubba down the street has done it.. and you see hacked together repairs on farm equipment, but its not a good idea and actually not to code structurally. I was involved with a whole series of tests for various welding methods and grades of rebar on a bridge job years ago where an engineer approved a welded splice but didn't directly call out that the bars to be spliced needed to be graded as such. It was caught by a CWI nearby and brought to attention by chance. Fingers pointed, job halted etc. Lab testing and even a field test on a splice that had not yet been poured over showed failure at 30% capacity vs that of the W graded bars that code requires. Lots of concrete and steel wasted to rip it out and start again, but hey... no nuns killed later down the road if the structure collapsed.
Just FYI is all on welding of rebar structurally.

 

[CarterKraft]

12"x12" column footings with a 8x8 rebar cage in the middle 4' deep, due to soil type these where belled (flared) at the bottom for more surface area on the clay/sand.

The wall footings are 6" wide with rebar dowels epoxied into the column footings.

This was all done to "looks good" spec.
The middle and rear post are 10ga 4x4, the front two are 3/16 4x4 for extra strength welding on hinges for doors.

 

[CarterKraft]

I don't know if I have a finished pic but here is a in process.

 

[fordguy]

I dig it! Did you bolt or weld the i beams on top? was this done through an engineer, or backyard math?