Building a Steel Barn

[rmasonjr]

I purchased trusses, purlins and the legs for a 30'x24' barn. I have staked the legs out, squared everything up and I have a question about leveling the legs. How do you level the tops of the legs?

For example, the legs will sit in 2.5' concrete and I'd really like to level the tops before setting the trusses and purlins. So, what is the easiest way? I was thinking of some laser-leveler to shoot from leg-to-leg and cut off the tops, but not sure what to use.

Any thoughts?

Thanks!

 

[Duffster]

I purchased trusses, purlins and the legs for a 30'x24' barn. I have staked the legs out, squared everything up and I have a question about leveling the legs. How do you level the tops of the legs?

For example, the legs will sit in 2.5' concrete and I'd really like to level the tops before setting the trusses and purlins. So, what is the easiest way? I was thinking of some laser-leveler to shoot from leg-to-leg and cut off the tops, but not sure what to use.
Any thoughts?

Thanks!

That is the way to do it. I would use a chain saw or a skill saw and sawzall.

 

[kennyd]

A real cheap method is some clear tubing and some water colored with food coloring.

Water tube level You can Google and find ,ore examples.

 

[CCWKen]

Your eave struts need to be level across the top, not the posts. An inch or so is close enough for posts. You can mark the posts with tape at the "sink line". Match that up to the top of the forms if that's how you're setting the posts. Or you can even weld an anti-sink plate to each post at the correct level. The sink line is measured from the top so each post is the same showing out of the concrete. It's pretty hard clean-cutting posts once they're up unless you have the tools/equipment.

 

[rmasonjr]

@kennyd - I had thought about the water level, but thought it might be easier to get a laser and shoot across to the posts.

@CCWKen - I have a sawzall and it cuts pretty good; while they are on the ground I can get some scaffolding or even my tractor's bucket to get me up to the top to get a clean cut. The posts are going to be set one at a time to a 2.5' depth, so I should get the same distance from the top to the top of the form.

Does anyone have a recommendation for a good self-leveling laser-shooter?

 

[MarkV]

Just wondering how you decided on the post at 2.5' deep? Most pole barns post are set at 4' and the friction of the backfill on that 4' of post has a great deal to do with the resistant against up lift forces like wind.

MarkV

 

[LD1]

A transit is the first thing that comes to my mind. They are very usefull. I don't own one but do know a few people that do and I always borrow them when doing some building/decking/concrete work etc. If you know anyone that has one, I'd ask to bottow it.


As to the 2.5' depth, I really cant comment other than IMO i think it should be sufficcient. Especially a steel post sed in concrete. Up here in Ohio I usually set deck posts and building posts to 36"-42". 30" clear down there I think would be good.

 

[rmasonjr]

@LD1 - Thanks - I'll see what I can find on google for a transit. Doing the research on this is interesting!

@MarkV - 2.5' set in concrete is plenty to hold it. If it were just filled with dirt, then 4' would be needed...

 

[AlanB]

The accuracy needed will depend a lot on what type trusses you are using and what they are sitting on.

On my building using poultry trusses the tops needed to be pretty darn level as the truss supported to the top of the post.

When you say a steel barn, are they all steel posts etc. or are you saying wood posts and steel skin?

Anyway, on my building done with 6x6 posts and steel poultry trusses (30 X 36) we set the rotary laser level in the center and marked all the post with that. It was easy. Just so it is said and not overlooked and you probably realize it and I am not trying to be insulting, but anyway, set your level (or transit or whatever you use) somewhere (I picked the middle, but really anywhere is fine, some folks want to be outside so they can leave it up without it being in the way and set a benchmark. A benchmark being somewhere you can repeat too. In my case, we picked the short post and marked the benchmark on it. This mark is the one when you take the level down and then put it back in place that you set everything too again. You want to pick one and repeatedly go back to it.

You may also want the benchmark to be something like a tree off to the side of the building so that you can reference back to it on the outside.

From that point, mark all the posts at "level" at a convenient to access height say 4' then measure up or down as needed to set various boards and heights.

Oh, and for cutting my 6x6 wood posts, took my worm drive circular saw and cut from 2 sides, went fine. (stood on scaffold)

 

[rmasonjr]

@AlanB - yeah, the entire shop is steel - trusses, legs (posts), purlins with galvanized tin 'skin'.
Thats a good idea on starting at the center. I was thinking of just picking the shortest set post and shooting to all the others and cutting them off, but starting in the center might accomplish the same thing?

I'm definitely going to fuss over it a good bit. I guess part of the fun of building it is playing with the details

Thanks!

 

[MarkV]

@AlanB - yeah, the entire shop is steel - trusses, legs (posts), purlins with galvanized tin 'skin'.
Thats a good idea on starting at the center. I was thinking of just picking the shortest set post and shooting to all the others and cutting them off, but starting in the center might accomplish the same thing?

I'm definitely going to fuss over it a good bit. I guess part of the fun of building it is playing with the details

Thanks!

Thanks for explaining the materials more. I for some reason thought we were talking wooden posts and setting them 2.5' deep. I now see you are talking about a 2.5' deep footing for each post. How does the post attach to the footing?

MarkV

 

[Raspy]

rmasonjr,

I'm still unclear on what you are doing. Bear with me.

On my steel posts that sit on concrete, I have bolts sticking up out of the concrete. Then the posts set on the bolts with jacking nuts under and lock nuts over the post foot.

I measured from the bottom of one post with a tape measure and took a reading with a transit. Then I measured all the rest and adjusted them to match. It turned out to be a bit tricky to get the lowest one high enough to begin with and the lowest one was my starting one.

Next adjust them to verticle without changing their height.

If you have some without bolts pre-set, as I did, you can set them on blocking and shims. Then mark the concrete footing, move the post a bit and drill in an anchor bolt. For these, use 3/4" or the size of your choice, threaded rod in grade 8. Drill a larger hole, I used 1", to allow for imperfect drilling. Cut pieces to length and epoxy them into the drilled holes with the jacking nuts and lock nut installed as you go. Try to get 6" penetration minimum and use Simpson bolt setting epoxy as it's approved for this use and will break the concrete before pulling out. Or you can use bolt setting, expanding mortar that sets in munutes. If you use this method screw on an extra nut that will be buried in the final slab. Be careful to keep the posts in alignment, both verticle and in line with the other posts. Run some strings and use some tie straps, clamps, stakes, 2 X 4s, etc as needed. Pry against other posts, the tractor bucket or a stake to stabalize till the mortar or epoxy sets.

If you choose to use this method you'll end up with the whole building sitting there on bolts that will get grouted in or poured in with the final slab.

It's very important to check your transit or laser level for accuracy!! Do this by taking readings in opposite directions to verify consistency before you commit. Before I got a good transit I had to take two readings on every post from opposite directions and average the difference to get a good number. this was very frustrating and time consuming. It also required a chart be made and updated as I went along.

I was able to get all my posts to within about 1/8 inch. They could have been closer but for pre-cast bolt problems.

I don't subscribe to the "within an inch or two is fine" theory. Do the best you can all the way up to avoid big problems later. With the jacking bolt method you can visually sight up along the trusses and end wall beams. You can see how straight they are and adjust as needed.

Be sure you have a good work platform! I made one from an entrance gate that is made of 2" square tubing. It has a gate that opens in and is about 6' X 3'. A very secure place to take up purlins, wrench on bolts and have lots of tools handy without fear of falling.

 

[crazyal]

How soon are you thinking of doing this? If you have a couple of weeks before hand I would suggest buying a laser level off of ebay and then selling it once you're done. I have a relitively cheap one but not Chinese made. Here's a link to a new one.

Spectra Percision Laser LL200 - eBay (item 120591313049 end time Jul-12-10 13:50:51 PDT)

I have seen other used ones sell for about half that and if you can wait until a better price comes you could sell it for about the same price you pay for it. I've been extremely happy with mine and decided to just hang onto it.

It uses an invisible laser and a receiver that has both an LCD arrow telling you if you are high, low, or in-line as well as a tone, fast pulses means you're too high, slow pulses too low, and solid tone for level. You set the tripod up sort of level, it has a bubble, and then it self final levels. I've used it for leveling the forms for my garage's cement slab, setting grade for drainage pipes, as well as several other projects. After 5 minutes at most you'll be an expert.

 

[Mace Canute]

A real cheap method is some clear tubing and some water colored with food coloring.

Water tube level You can Google and find ,ore examples.

Years ago, I bought a small water level kit that supplied the clear hose ends that would thread onto the ends of your common everyday garden hose. It was on sale for cheap, and I thought it was one of those things that if I ever needed it, would sure make the job go easier. It's around somewhere....

 

[Hawghauler]

My first shop the builders left a good 6 inches extra sticking up on the posts and it turned out to be a blessing as they did a poor job in compaction and the posts settled on one side which was starting to ripple the metal. They were able to raise the cross beems and re-adjust, accounting for the settling and the shop was fine. (all warranty work). Just a thought.

 

[dfkrug]

I was thinking of some laser-leveler to shoot from leg-to-leg and cut off the tops, but not sure what to use.

I am also working on an all-steel building. To determine the exact length
of the columns, I use a laser tool called RoboLaser, from Toolz. I bought
it when it first came out back in the mid 90s, and I used it extensively
to get my grades correct in digging the foundation for my house.

It is a motorized self-leveling laser that is remote controlled. It sends
out a dot that is visible in daylight (no special detector needed). The
remote turns it on/off, and rotates the body of the unit. I mount it
in one location on a tripod and mark where the dot hits my columns.

Toolz is now RoboToolz, and the device has been improved. There is even
a super-bright green laser now, good for 300 ft, instead of only 100 ft.
You can find the older tool used, or pay $100-150 for the newer one, new.
Several people I know bought these after seeing mine work, and how
reasonable it was.

 

[Raspy]

Here are some more pix of our project. Next is the roof.

 

[Raspy]

More pix

 

[Raspy]

Still more

 

[Raspy]

Some things that have really been helpful with this project are the basket for the forklift made from scrap steel, the A frame in the tractor bucket made from 1 1/4 inch pipe and chain, the tractor which has moved many, many tons of material, dug the foundation, dug about 700 feet of ditch, dug the septic tank hole and graded the whole area.