Concrete ceiling

[Press5]

Hey guys,

I'm pouring a ceiling out of reinforced concrete supported by cinder blocks on all sides. Reason being is that the project should be underground and as such needs to be able to hold a lot of weight (including potentially a vehicle). The longest span is only 14 feet or 4.25 meters, and I'm aware that European homes often go as far as 6 meters. My only question is how thick should I make the pad. I am reasonably well experienced working with concrete and have done similar pours before and always opted for 6" as it seems to be a safe number. However, those pours never exceeded a 8' span. What is the thickness I should pour the ceiling?

Thank you much,
P

 

[Gozo]

You're using some form of concrete support beams and/or piers, right? Take a look at some local parking decks, you can see the construction and deck thickness there. Since you said this was a ceiling, I have to suppose that someone or some thing may be under this. This really is the type of project, that if you have to ask, you're probably over your head (pun intended). If a floor cracks or chunks out, it's ugly and a pain in the ****, but no one gets crushed in a collapse. Extra caution applies here.

 

[DougWil]

You need to have an engineer design your slab, not some guys on a garage forum in another country.

Thickness, strength of the mix, rebar grade, area and placement and the design load all are factors that control the design.

 

[ford fanatic]

You need to have an engineer design your slab, not some guys on a garage forum in another country.

Thickness, strength of the mix, rebar grade, area and placement and the design load all are factors that control the design.

This. A structural engineer.