# metal building/concrete question



## drfishalot (Sep 9, 2004)

getting ready to build a metal barn. talked to a guy yest who told me that the concrete would cost as much as the building. kind of surprised me. he went on to say that to do it "right", a footing should be poured all around the building and then a deeper concrete pier where the I-beams bear weight. the weight bearing piers make sense. and then he said that the guy he uses pours 5" concrete. 

I was surprised at the 5" thickness, as well as the "need" to pour a footing all around the edge. when in reality you don't even "need" to pour a concrete slab- I figured that they would just pour the slab though- not a footing.

so do you really need a footing poured and do you need 5" of concrete? the heaviest thing, other than the structure, might be a small 30 HP tractor on the concrete.
Vic


----------



## Rusty S (Apr 6, 2006)

pm 007. rs


----------



## bwguardian (Aug 30, 2005)

You really should pour a perimeter grade beam. As far as the 4" versus 5" of concrete...this is only relative to the amount of steel going into the slab...W.W.F. versus #5 bars @ 18" o.c. each direction. It also makes a difference what kind of soil you have...what part of town are you in? What is the dimension of your structure (metal building)? Contact Mikey (007) here on this board and I bet he can take car of it.


----------



## therealbigman (Jul 14, 2010)

I'm not a builder or a concrete guy, but I would have the footing for sure, whats goona support the weight of the builing, also, I would have a nice size beam of concrete going right down the middle of my slab, as far as the thickness, I don't see why 4 inches wouldn't work, Good luck with your project also you didnt metion the size building you are erecting , my thoghts are with a 20 x 30 30 x 40 type of building.


----------



## wickedinhere (Oct 4, 2004)

Build a pole barn then pour the slab inside way cheaper and the concrete will only support what you have on it. The poles will support the barn i built a 30x30 like this
and have no problems or cracks and my slab is 4". Here is my pole barn.















inside after concrete.


----------



## drfishalot (Sep 9, 2004)

well, I'm thinking 40 x 60, possibly with an upstairs area/small 2nd floor.

I'm in oklahoma, so I don't think 007 would be interested lol.

I guess the metal I-beams would be on 20 ft centers, and free span. so I get the piers part, you would need a good support at the wt bearing areas, but why the footing all around. why not like what 
wickedinhere did, where the concrete floor only has to support what is sitting on it. soil is "clay like"


----------



## drfishalot (Sep 9, 2004)

I like this shape:
http://shop.ebay.com/?_from=R40&_tr...=2+story+metal+barn&_sacat=See-All-Categories

I'm not buying it off of ebay, its just a pic.


----------



## bwguardian (Aug 30, 2005)

drfishalot said:


> well, I'm thinking 40 x 60, possibly with an upstairs area/small 2nd floor.
> 
> I'm in oklahoma, so I don't think 007 would be interested lol.
> 
> ...


With a 40' x 60' shape you will additionally want an interior beam in the 40' width to break it up to two 30' x 40' areas...concrete will crack in a square if you give it a rectangle.

If planning on a 2nd story that is additional weight and even more reason for a good foundation. Having the beams/footings gives it lateral support unless you plan on sinking the columns deep. With the clay soils you have even more reason for stability. I can go on and on but the bottom line is sure you can do a pole barn but it depends out what you want and how long you want it to last.


----------



## wickedinhere (Oct 4, 2004)

The guys that built mine are in Oklahoma(wilson pole barns) they have a website with prices listed and it will save you money. I am getting ready to build a 30x60 and finish the inside to live in.


----------



## TerryM (Apr 19, 2005)

You might want to add a couple of things while you are at it.

Floor drain or two.
Plumbing for a bathroom/shower. (your wife will thanks you, must have)
Footings for a auto/shop lift. (pretty cheap used, and very handy)
Bigger barn (never enough room)

Terry


----------



## Roger (Aug 12, 2005)

We just finished a 24 X 32 that turned out pretty good for a kit. We did all the work except for forming the slab. Dug the footing to 12"s so adding the 4" slab it was probably 16 to 18"s all around. Had a buddy come in and do the forming and rebar work and pour the slab. The rest was on me and my son and some neighbors. Oh, except for hanging the door. I think it turned out pretty well...


----------



## drfishalot (Sep 9, 2004)

TerryM said:


> You might want to add a couple of things while you are at it.
> 
> Floor drain or two.
> Plumbing for a bathroom/shower. (your wife will thanks you, must have)
> ...


floor drain-- check
plumbing for full bath-- check
lift-- I don't really work on stuff anymore
bigger barn--.............well, I thought I could get the 40x60 for 20-30k, lol yeah right, bout twice that. now if I go to a plain ole rectangle, no upstairs metal barn I could get it a lot cheaper. the there is insulation--check, the small living part will have central heat and air--check.

can you finance these buildings like a home with the current low interest rates?

barn guy told me the concrete flooring was going for about 6.75 a sq foot- is that reasonable


----------



## osobrujo (Jan 13, 2005)

If your support posts/frame is put up first, the posts are in concrete, three feet in the ground. These post in concrete will support the building, therefore you can pour the slab later, since it will only support the weight of the heaviest object you put in the building.
If you pour your slab first and your walls will be on the slab, the slap will be supporting the weight of the walls and the building. Now, you will have to dig the footer to help keep the slab from cracking, with all the weight.


----------



## Bubbaette (Apr 10, 2005)

My husband built his about 15 years ago. It is 30 x 50 with 16' eves and has a 5" slab with beams (or whatever you call the things that run all around and through the middle) and 15 - 10' x 36" bell bottom piers. Here's a diagram. But -- he overbuilds EVERYTHING!

He has fairly heavy stuff in it and so far it hasn't gone anywhere. 

This is a rough diagram.


----------



## TIMBOv2 (Mar 18, 2010)

THAT ONE WILL BE THERE FOREVER


----------



## BullyARed (Jun 19, 2010)

Bubbaette said:


> My husband built his about 15 years ago. It is 30 x 50 with 16' eves and has a 5" slab with beams (or whatever you call the things that run all around and through the middle) and 15 - 10' x 36" bell bottom piers. Here's a diagram. But -- he overbuilds EVERYTHING!
> 
> He has fairly heavy stuff in it and so far it hasn't gone anywhere.
> 
> This is a rough diagram.


Better than a nuke bunker


----------



## BullyARed (Jun 19, 2010)

Roger said:


> We just finished a 24 X 32 that turned out pretty good for a kit. We did all the work except for forming the slab. Dug the footing to 12"s so adding the 4" slab it was probably 16 to 18"s all around. Had a buddy come in and do the forming and rebar work and pour the slab. The rest was on me and my son and some neighbors. Oh, except for hanging the door. I think it turned out pretty well...


Very nice job and building. Excellent! I like to one like this.


----------



## Can't buy a bite (May 19, 2010)

Probably the biggest defining factor will be your local building codes. Roger's building is a perfect example. Very nice looking structure but it has no wind loading what-so-ever. If you're under city or county jurisdiction and permitting, they will have final say what you can and can't do.

As far as concrete, I've built turn key commercial metal buildings for a General Contractor for many years... The foundations are based upon Geotechnical engineer's soils reports and recommendations, combined with the column reactions from the metal building manufacturer.
I can't give you applied knowledge of soil conditions in Oklahoma, but in the Gulf Coast the soils are very expansive. Couple that with the Texas heat and we have the reason for 5" concrete. We try to maintain 1 1/2"-2" of concrete cover over rebar to prevent the steel from heating and "popping up" the concrete and you want the rebar placed in the upper third of the slab thickness to resist the expansive upheaval forces of the soils. The reason concrete with wire mesh typically fails, the mesh always ends up near the bottom of the concrete, so it does nothing to stop the upheaval forces.

Metal buildings can have bay spacings up to 30' although 20' & 25' are the most common. The wider the bay spacing, the stronger the main frames have to be to carry the load.

PM me if you have any questions, I'll be happy to help.


----------



## Barbarian (Feb 12, 2009)

osobrujo said:


> If your support posts/frame is put up first, the posts are in concrete, three feet in the ground. These post in concrete will support the building, therefore you can pour the slab later, since it will only support the weight of the heaviest object you put in the building.
> If you pour your slab first and your walls will be on the slab, the slap will be supporting the weight of the walls and the building. Now, you will have to dig the footer to help keep the slab from cracking, with all the weight.


X2. The exterior beam and the 5" thickness is not what is making it so expensive. Yes, they add to the cost but not excessively.


----------



## CHARLIE (Jun 2, 2004)

I dont think anyone mentioned that the bolts or steel thats holding the building to the slab must be in plenty of concrete not just 5 inches. Yes beams around the outside and throughout the building will be a must if you dont want cracking. If the foundation isnt right then the entire building will be junk later.

Charlie


----------



## 007 (Mar 11, 2008)

When I poured this 40' x 40' slab for ShadMan, I had a 16" w x 18" deep exterior grade beam with 6- #5 re-bar in the beam and #4 re-bar on 16" centers in the 5" slab. I think $6.75 a sq ft is a bit high.


.


----------



## twoZJs (Jul 23, 2008)

"Quote; a footing should be poured all around the building and then a deeper concrete pier where the I-beams bear weight. the weight bearing piers make sense" 

I believe the major purpose for the footing beam is being missed here on this tread by the conversation/concentration is focused on supporting the building weight. That avenue will be taking care of AFTER the building WIND LOADING vs ANCHOR abilities are addressed. Everything I've seen so far here will take off like a kite except the pole-in-the-ground route. The pic above this posting, those bent/formed sheet metal channels may peal from those spaced anchors like a lid off of a good can of potted meat. 
Yes, the floor slab should be able to float separate from the bond beam and piles, so pour the slab last with true expansion felt. 
Anchors, I would not install anything less than 3/8 'Js' on 24" ctrs. At each support post, needs to be addressed w/special loading support. 
Pole route; Each pole should be down a min of four feet in the gnd. Each pole should be set on a min four inch thick 18" dia slab, back filled with two 80# bag of crete with wire. 
Just my .02. I like to see something still there after a big blow.


----------



## drfishalot (Sep 9, 2004)

Excuse my ignorance:
-I believe the major purpose for the footing beam is being missed here - 
-I had a 16" w x 18" deep exterior grade beam -

I am guessing that you guys are calling the concrete in the footing a "beam" and not actually putting a steel beam in there-correct?

and this " wind loading", what are we talking about here. most kits are rated to like 90-100 mph. I assume that has to do with the fastening of the sheet metal to the " horizontal stud things" (are those purlins?), as well as the fastening of the vertical supports to the flooring/pier assembly?

thanks for all the info guys.


----------



## bwguardian (Aug 30, 2005)

drfishalot said:


> getting ready to build a metal barn. talked to a guy yest who told me that the concrete would cost as much as the building. kind of surprised me. he went on to say that to do it "right", a footing should be poured all around the building and then a deeper concrete pier where the I-beams bear weight. the weight bearing piers make sense. and then he said that the guy he uses pours 5" concrete.
> 
> I was surprised at the 5" thickness, _*as well as the "need" to pour a footing all around the edge.*_ when in reality you don't even "need" to pour a concrete slab- _*I figured that they would just pour the slab though- not a footing.*_
> 
> ...





drfishalot said:


> Excuse my ignorance:
> _*-I believe the major purpose for the footing beam is being missed here - *_
> _*-I had a 16" w x 18" deep exterior grade beam -*_
> 
> ...


So at first you did not think you needed a perimeter grade beam...and now you have a perimeter grade beam?

The main purpose of an exterior grade beam is of course load bearing capacity, but it also serves to keep the compacted substrate fill from being washed out which would cause slab failure.

The structure may be rated for 90-100 mph but that typically stops at the top surface of the slab...ie. there is no lateral stability. This is why most, if not all metal building manufacters want a seperate Engineer to design the slab on grade.


----------



## WilliamH (May 21, 2004)

If you want it done right hire a General Contractor who is familiar with the erection of pre-engineered buildings.

Request a soils report to be done by a geo-technical engineer.

Have the foundation designed by a structural engineer based on the recommendations in the soils report and the reactions provided in the pre-engineered drawings.


----------



## drfishalot (Sep 9, 2004)

So at first you did not think you needed a perimeter grade beam...and now you have a perimeter grade beam?---sorry BWGuardian, I got ya confused.....

-I believe the major purpose for the footing beam is being missed here - thats a quote from twoZJz

-I had a 16" w x 18" deep exterior grade beam - thats a quote from 007


-


----------

