Concrete Slab

[karoc]

Which will be for a pole barn that will have living space and shop space. The contractor saying the slab will be 4" with fiber in concrete for strength. Being somewhat old I am use to seeing rebar or wire mesh in slabs,I know nothing about fiber in slabs. What are ya'll thoughts on this,my shop will be for woodworking etc I don't think be keep a car in there but?

 

[OptionalStop]

I would not pour a slab without at least wire mesh in it. When the concrete cracks, the reinforcement being either mesh or rebar will hold it together.

 

[ConCretin]

Karoc, Give my Guide to Floor slabs in the link below for some thoughts on fiber vs steel reinforcing. In a nutshell, neither makes the floor stronger. Fibermesh minimizes plastic shrinkage cracks and allows you to space your control joints further apart but doesn't do anything once cracks occur. Steel reinforcing doesn't prevent cracks but it holds them together once they occur.

You didn't mention how big your floor is but that will have a lot of bearing on how you approach crack control and restraint.

 

[karoc]

Thanks guys,I was thinking that maybe contractor is taking a short cut. Slab is 32'x70' 4" thick

 

[Kaizen]

My 1050 awesome ft 4K psi slab is 6” thick. Took three New England winters to even see a crack. Hairline on expansion joints. Only fiber in the field. Has rebar in the thickened edge which keeps it all together. Pretty much the norm around here now


Sent from my iPhone using Garage Journal

 

[rok_hunter]

Concrete guys are out back as I type this, putting the finish on my NW Florida 30x40 pole barn slab. Mine is 4", 3,000psi fiber-reinforced with a 12" footer, which is also the only spot that got rebar (two pieces throughout). They used metal keyways integral to the slab that, according to the conversation about an hour ago, are where the slab will eventually crack for strain relief. They said it's the preferred method nowadays vs using a concrete saw or other tools to set strain relief joints in the slab, and results in much smaller cracks/gaps throughout. I also don't plan to put anything heavy on it, topping out with a 3/4 ton truck being pulled in now & then for maintenance, and the builder/engineering review said that slab will be more than sufficient for what I'm doing.

Sent from my Pixel 2 XL using Tapatalk

 

[MetalBuildingFun]

NW Florida? Are you in hurricane country? Did you get this footing engineered?

 

[tdkkart]

My guy said the only reason for wire is if you've got a bunch of extra to hide, and his reasoning made sense, if there's enough force there to shear concrete, do you think a piece of 16ga wire is gonna stop it?

 

[ConCretin]

Slab is 32'x70' 4" thick

I'd suggest one cut the long way and five across. This will give you 16x12 panels, which are a bit on the large side but should be fine with some attention to slump and curing.

Concrete guys are out back as I type this, putting the finish on my NW Florida 30x40 pole barn slab. Mine is 4", 3,000psi fiber-reinforced with a 12" footer, which is also the only spot that got rebar (two pieces throughout). They used metal keyways integral to the slab that, according to the conversation about an hour ago, are where the slab will eventually crack for strain relief. They said it's the preferred method nowadays vs using a concrete saw or other tools to set strain relief joints in the slab, and results in much smaller cracks/gaps throughout. I also don't plan to put anything heavy on it, topping out with a 3/4 ton truck being pulled in now & then for maintenance, and the builder/engineering review said that slab will be more than sufficient for what I'm doing.

I'm not sure metal keyway is the preferred method or results in smaller cracks. I haven't seen metal keyway in twenty years and the amount of shrinkage isn't affected by the type of control joint but it does the job. You are basically creating a crack rather than encouraging one with a saw cut or groove. The downside is the cost and the risk of corrosion having metal so close to the surface. Btw, save yourself some money and skip the fiber mesh. You've already broken the slab into small sections. There is minimal risk of additional cracks.

My guy said the only reason for wire is if you've got a bunch of extra to hide, and his reasoning made sense, if there's enough force there to shear concrete, do you think a piece of 16ga wire is gonna stop it?

Concrete usually cracks as the result of tension from drying shrinkage. You are correct when you say wire won't prevent cracks but it does hold them together. Personally I wouldn't place a slab without wire or bar. It's cheap insurance to maintain the integrity of your slab in the event of unexpected circumstances.

 

[rok_hunter]

NW Florida? Are you in hurricane country? Did you get this footing engineered?

Yes, and yes. The plans for the entire structure, slab included, needed an engineering review/approval before permits could be pulled.

Sent from my Pixel 2 XL using Tapatalk

 

[dcg9381]

Thanks guys,I was thinking that maybe contractor is taking a short cut. Slab is 32'x70' 4" thick

Not necessarily. And certainly you have the right to specify steel if you want it. Around here, I do steel and beam type construction. Up north - I've got family member doing the fiber route. Both are valid, but ask questions..

 

[MetalBuildingFun]

Yes, and yes. The plans for the entire structure, slab included, needed an engineering review/approval before permits could be pulled.

Sent from my Pixel 2 XL using Tapatalk

That footing and foundation blows my mind, lol.

Mine is #6 rebar-2 top and bottom in my 12"W X 24" deep footings, including the corners being #6 rebar as well. Then there is #4 rebar on 12" spacing throughout my slab. Just goes to show things are different depending on location and soils regardless of the weather.

 

[karoc]

I'm use to seeing slabs for houses and not pole barns,which I was told that slabs for pole barns are floating slabs(new to me) Since there is not lot of weight can get by(I guess) with thinner slabs and basically no beams. But the sub base has to be good to help support the floating slab,which I did not ask about the sub base for the slab.This is a 32'x70' pole barn with 1000sq ft living space then rest as my hobby type woodworking shop. Which this locate in East Tx close to Toledo Bend,so trying to gather all info I can before sign on dotted line. Guys thanks for all responding,getting a good ideal

 

[rok_hunter]

That footing and foundation blows my mind, lol.



Mine is #6 rebar-2 top and bottom in my 12"W X 24" deep footings, including the corners being #6 rebar as well. Then there is #4 rebar on 12" spacing throughout my slab. Just goes to show things are different depending on location and soils regardless of the weather.



[emoji38]_hitti

I know our codes are different than south FL, and I think even different than those within ** miles of the coast. [emoji1745]

Sent from my Pixel 2 XL using Tapatalk

 

[Kaizen]

I'm use to seeing slabs for houses and not pole barns,which I was told that slabs for pole barns are floating slabs(new to me) Since there is not lot of weight can get by(I guess) with thinner slabs and basically no beams. But the sub base has to be good to help support the floating slab,which I did not ask about the sub base for the slab.This is a 32'x70' pole barn with 1000sq ft living space then rest as my hobby type woodworking shop. Which this locate in East Tx close to Toledo Bend,so trying to gather all info I can before sign on dotted line. Guys thanks for all responding,getting a good ideal

Is this a single story? Mine is a completely open design with no bearing points.
Anyway i would just check if you have a wall supporting two floors of living area sectioning off the house part. In that case I think I’d ask for a thickened beam under the wall like the edges should be getting. Also run bar in that beam. Just a thought. Can’t hurt.


Sent from my iPhone using Garage Journal

 

[Leaflessshadetree]

I like fiber but it is not a replacement for rebar or wire mesh.

 

[karoc]

Is this a single story? Mine is a completely open design with no bearing points.
Anyway i would just check if you have a wall supporting two floors of living area sectioning off the house part. In that case I think I’d ask for a thickened beam under the wall like the edges should be getting. Also run bar in that beam. Just a thought. Can’t hurt.


Sent from my iPhone using Garage Journal

Its single floor,space above the ceiling will just be for the ac furance,plumbing so there is really no weight since the 6x6 post and the wall girts will be carrying the weight. But in my shop I have mill that maybe weights in at 2500 lbs which is spread over I guess 2'x3' area then lathe that is about 1300 lbs plus few other things that about 500lbs or less. But all that will be spread out in my hobby shop.