# Does NJ IRC 2018 Require Steel Reinforcement in Concrete Slabs?



## nickedemus (Apr 13, 2021)

I don't see that it does. Table R402.2 specifies minimum compressive strength. I don't see any requirements for welded wire mesh or rebar. This would be for a garage slab.


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## my250r11 (Apr 13, 2021)

IMHO it is because a residential/commercial slab is not considered structural. If you have interior load bearing walls or columns they should have footings. It is not disallowed but if you use mess or rebar it should meet the requirements of the concrete manual or ACI. Most slabs in commercial are designed by an arch. or eng. and are inspected to meet what is on he plans.


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## Joe.B (Apr 13, 2021)

There are so many possible factors and potential conditions that could affect the decision making thought process that this is not a simple answer. Required or not it may be a good idea, remember code is a minimum only and not a best practice guide. When factoring the overall cost of building, saving a few bucks on rebar may not seem worth it.


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## nickedemus (Apr 14, 2021)

I talked to NJ DCA and they said that the rebar requirement is design-based, depending on loading and footings, etc. (hence why only the installation method is addressed in the IRC (R506.2.4). 

The IRC is pretty specific about the design of floors, walls, and roofs, so I guess I expected it to have a similar level of requirement for slabs.... But I guess no one is in danger of being injured by a collapsing slab on grade lol.


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## ADAguy (Apr 14, 2021)

Potential for ground settlement, frost heaves, interior partition relocation flexibility if ceiling joists clear span spaces, etc.?


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## nickedemus (Apr 15, 2021)

ADAguy said:


> frost heaves, interior partition relocation flexibility if ceiling joists clear span spaces, etc.?


It's a slab on grade in an attached garage. It's insulated from frost heaves. If earth is not compacted to spec, yes there could be ground settlements. Unsure what interior partition relocation flexibility and joist clear span have to do with it?


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## ADAguy (Apr 15, 2021)

Flexibility to relocate nonbearing interior walls or not.


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## nickedemus (Apr 15, 2021)

Oh. Well, if someone wants to build walls in the garage in the future, I guess they can go ahead and do that. But I'm not going to design it for that. I'm just designing it to be a garage.


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## ADAguy (Apr 15, 2021)

missed the garage part, sorry


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## Paul Sweet (Apr 16, 2021)

R506.2 says "Where provided in slabs-on-ground, reinforcement shall be supported ..."  It doesn't say that reinforcement is required.

Reinforcement in residential slabs-on-grade usually isn't needed for strength, but is more for crack control.  Fiber strand reinforcing might be an option.


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