Shop floor

[Wade1984]

I am going to pour a floor in a pole barn. Since the barn is already built and no weight from the barn will rest on slap, I was thinking of pouring a straight 5" slab with no beams. I am trying to decide whether to use rebar, rebar and fiberglass, or just Fiberglas. Any ideas would be greatly appreciated.
 

[Mark - IN.]

Wade, I suppose it depends on what you're going to use it for. In my newest barn, I had a concret floor poured, 4" thick, reinforced with both rebar and fiberglass because I figured it would make a difference and it has. Heaviest tractor ever on it about 10,000 lbs. Its good for moving and storing pallets of fertilizer and feed, but I don't have a forklift so I don't know that I need concrete. Its ok. Has cracks, no big deal. I don't remember what it cost, but if I had to do it all over again, I think I might not have poured the whole thing and stopped at a slab for an office and a working pad for the hoist, but thats me. My other barns got dirt floors and do just fine. Maybe I should be happy with the concrete and stop taking it for granted? Maybe slab with ratboard around its more valuable than I notice. I know there's stuff living under it, not sure what though. I know there's stuff living in my barns with dirt floors, nothing big though that can't be dealt with. Oh well.

Good luck.

Mark
 

[504]

Rebar at the door and mat for the rest.
 

[Puddles]

Had an engineer tell me one time that there is absolutely no structural value in concrete mesh, all it does is hold the concrete together after it breaks.

Few things I had done for my shop floor, at each door opening I went with a thickened edge. I dug a 12” wide by 12” deep trench.
On each side of the 6” x 12” posts the concrete crew nailed HTT-16 clips to tie the slab to the post. But one time I seen a set of blue prints for a pole barn there was a detail for drilling a hole through the posts and sticking a # 4 bar through the hole and bending it back at about 45 degrees into the slab area with about 3-feet long tails.
Do yourself a big favor, don't forget expansion joints!

http://www.strongtie.com/products/connectors/LTT-HTT.asp



 

[Puddles]

One thing I forgot to mention. If you hire out the placing of your slab, guys who do flat work for a living love to pour concrete wet! Makes it easier on them, so watch the slump of the concrete! Water just kills the strength of concrete! Then again water is your friend during the cure process. This time of year it's probably not a big deal, but when the weather warms up, you really want to keep the slab as wet as possible! On job sites it is required to cover a pour with white visqueen or burlap fabric.

http://www.youtube.com/watch?v=iOBK6NGfMtE
 

[George Marsh]

A friend and concrete finisher put my 6 inch floor down, 30x40. Used my self leveling rotating laser, found a spot where the laser just hit the bottom of overhead door. Then put a 16p nail in every post where the beam hit. Only had to use one form board at the overhead door, which we drilled holes in for re-bar to connect the slab to the apron. Friend used a Georgia buggy to truck the concrete inside the barn. Concrete finisher doesn't like fiberglass. We used wire and cure and seal sealer. Day later he cut the lines in floor. 4 years later and no cracks.
 

[Puddles]

Georgia buggies?! Now there's some guys who aren't afraid of work! Or were they powered Georgia buggies?
 

[Stephen Newell]

I guess a lot depends on how you are using the shop and the soil you have. I have sugar sand where I'm at and the shop I have doesn't have equipment driven in on it. I poured a floor 3 1/2" thick with just remesh in 1985 and it doesn't have any cracks at all.
 

[Russ from MN]

You didn't say if this is a barn for livestock or a shed for equipment, it makes a difference. I like rebar. especially around the perimeter, and a lot depends on the base.
 

[Puddles]

A girlfriend of my wife has been an Iron Worker, (rod buster) for 30-years. She was telling me one time she placed the rods for a slab on 12-inch centers. She said when the slab dried it cracked at every bar! Makes you wonder what the coverage was. Most places require 3-inches, but in some slabs that can be hard to do. A lot of home owners make the mistake of placing the bar right on the ground, or standing on it while making the pour. Need to use lots of dobies if you plan on standing on top of the bar.

http://www.lowes.com/pd_82538-286-099102_0__?productId=3044209
 

[Russ from MN]

That sounds to me like the concrete was poured way to wet! Some people like to soup it up so its self leveling, and it makes for very weak concrete, and a lot of shrinkage. Also maybe the rebar was too close to the surface, or it was not floated enough.
 

[Pops1532]

Make sure your base is compacted well and doesn't have any sod that will decompose.
5" minimum thickness.
#4 rebar spanning any/all excavations (plumbing or electrical trenches, etc) and across the door openings.
How will the building be used? If you're going to store heavy equipment you'll want rebar. If it's just going to see automotive use then 6X6 wire mesh will do.
Fiber has it's good points.
What mix are you going to use? I suggest 4000 psi for flat work.
Cut the relief grooves the day after the pour.
As others have said watch the slump.
 

[paul]

Rebar. For sure. Controls the cracks.

Some like fiberglass to keep the small bits from chipping loose.

Others don't like fiberglass in a shop because the fibers showed up on the surface, and make ichies.

--->Paul
 

[dpendzic]

6 x 6 mesh 1 1/2 inches from the surface will work good. Fiberglass fibers help a lot but makes the surface rough.Use low slump concrete or add plasticizers to increase workability.Air entrainment helps reduce shrinkage and increase durability.
 

[George Marsh]

Motorized buggies, Overhead door was on one end, trucked some concrete 40 ft. I think I figured that a quarter inch cost me $100, so I purchased a self leveling rotating laser and had the dirt near perfect.