slab on grade thickness

[archeng59]

I have specified a 4" thick slab-on-grade for most projects that do not have wheeled traffic or heavy equipment. Recently, one of my architectural clients started requiring that I show a 5" slab-on-grade instead of the 4". Their reasoning is that the 5" slab is the new industry standard. Did I miss some articles or a meeting about this? Anyone else changing from 4" slabs to 5" slabs? My old boss used to spec 5" slabs but I changed back to 4" slabs after starting my own business because contractors were always wearing me out about the extra concrete costs. Just curious if 5" is becoming the new 4".

 

[frv]

I haven't been practicing long enough to comment on whether it is an industry standard, but our company standard is 5".

 

[kaisersoze]

In my experience 4" vs 5" is really client's call, we all know that 4" works just fine. I would say 5" is more common these days but I am not aware of any new standard that requires you to go to 5".

Kaiser

 

[ron9876]

I have used 4" slabs on grade in buildings for years unless there is a load consideration.

 

[a2mfk]

Same as Ron, 13+ years in Florida... Warehouses are a different beast.

 

[archeng59]

Thanks, everyone. I agree that a 4" slab is ok for people spaces. Other occupancies are different.