concrete questions?

[zfrank07]

slab is going to be 24x24 and 4" deep.....its concrete with the fiber....should i get rebar or wire put in it also? if so which one? if i go with rebar how much rebar would i need to get? what size? and how far do you put it apart???

 

[zfrank07]

also insulation questions? what kind of insulation would be best for me to use...ive search and search and cannot seem to find anything, only pics of garages that are insulated, dunno what i need r13 or r30 or ?????

 

[walrus]

These questions are pretty general, where are you?, what are you going to do in your garage?

 

[zfrank07]

im in ky...garage is going to be studded, osb and vinyl siding, metal roof!! i am going to use to park cars and work on projects out of it.

 

[brownbagg]

rebar is for load factor, does not do the same job as fiber and mesh.which are for shrinkage crack. If you going run a bulldozer or peterbilt on your slab, yes rebar. Your pickup, not needed but you can do if you want. rebar not cheap no more

 

[GB Hicks]

Get the rebar. If you are going to make something that will last over-build it a little. Rebar is not cheap,but it is cheaper to put it in now instead of later when the slab has cracked.

 

[kbs2244]

At the very least get the mesh mats of reinforcing steel and tie them together or overlap them one row.
Most pros I deal with don't think much of the fiber.

 

[shmo]

I think most pros don't think much of the fiber because it is slightly harder to work.

The question of "how much weight will you put on it" is the key here. Another question is geography. Where will your garage be? Is it extremely cold? Do you have issues with road salt?

For a normal residential style garage (in my area), I think fibermesh thrown in with a 5-sack mix will be more than adequate.

 

[shmo]

Oh,

and I recommend placing a vapor barrier under the concrete. I cannot believe how many guys do not do this simple step.

 

[zfrank07]

what do u mean by vapor barrier? the weights isnt going to be a big thing...most weight will be a full size truck... and the wifes car. it gets cold here but not extreme cold temps. im in ky. quite a bit of road salt when it does snow here.

also insulation, what insulation would you guys use?

 

[ddawg16]

The weight of the cars....and the wood...the walls, the tools, the roof.....

Do rebar....you can't add it after the fact....and it's a very small cost compared to everything else.

Look at this way....would you paint wood without putting on primer?

 

[hydramatic]

vapor barrier=visqueen..get the thickest they sell..

 

[FlameOut]

I did re-bar in my 28 x 34. Placed about every 18". My slab is also between 7 & 8" thick (was supposed to be 5 but I messed up)

I'm glad I put the re-bar in. Probably added about $400 to the job, but I feel better. I also used a vapor barrier (6 mil plastic) on top of my gravel fill

 

[tcianci]

A vapor barrier is always a good idea, lots of production guys don't like going with it because it takes forever and a day for the slab to set up so thay can finish it. The re-bar is overkill, big time. If I were pouring a 4 inch slab with fiber-mesh in the mix, I wouldn't even worry about the wire. The most important thing in preventing concrete cracks is to make sure that your fill is adequately compacted and you use control joints on larger slabs.

 

[krooser]

I poured my floor in '94 with 4" fibermesh and a six bag mix. I have two tiny cracks in the slab and they appeared within two years.

I have a HEAVY 9000# Weaver two post lift that has had a loaded E350 on it and I don't have any cracks anywhere near the lift. No rebar... no wire. The contractor that did the pour always used the fibermesh with good results.

Now if you have poor soil conditions you may need some re-inforcing but I worked a concrete crew years ago and we poured hundreds of driveways, slabs and basements without using any steel.

My shop is over a backfilled sand base without any vapor barrier since the sand drains very good.

 

[cyamaha2007]

we use fibermesh at work but ony in small projects like cattleguards grade rings septic tank caps. The stuff seems to break up in transport more often than rebar enforced concrete. I do quality control for the reco walls that you see under overpasses and huge retaining walls. They have tried to use fiber in test pours for our 5x8 panel molds and when lifted out by the back side in 12 hours they simply broke in 2. All 7 of them. We pull the forms with rebar every 12 hours no problem. I am using epoxy coated rebar in my shop floor we have a nice stash of it in the woods at work.