Is steel required in concrete floor slab?

[rrrrrrrrrr]

Our builder has just poured the concrete floor of our 3m x 4m kitchen extn and as I don't think he put any steel into it.

As far as I can see he started with a hard core base, then a plastic layer, then foil backed foam insulation (a lot of the foil got ripped from them walking on it) and then poured a layer of readymix concrete.

Is this ok? Do we not need a reinforcing steel grid in the cement?

Maybe the slab is thick enough so it's not required?

I just want to get my facts straight before I ask him about it tomorrow.

 

[j26]

I think that's fine. If it was an upper floor, reinforced steel would be required, but I don't remember ever seeing steel in a ground level floor, even when the floor in the living room in my last house had to be dug up (leak).

 

[sfag]

Mine has - I believe the site engineers said it needed double layers of steel of less strenght than the foundations so it might be regulation?

 

[jhegarty]

No , no need for one.

I presume you are not going up more than one floor ?

 

[CharlieR]

An anti crack mesh A152 or A252 possibly?

 

[DELLBOY 08]

Concrete has high compressive strength but low tensile strength.

A142 steel mesh reinforcement (which has high tensile strength) is commonly used in ground floor concrete beds to compensate for this.

Ask the builder why he didn't use it.

 

[wexford dude]

The standard ground floor slab would not require steel mesh reinforcement.The standard slab is a floating slab.This means that the weight of the slab is borne by the compacted hardcore underneath the floor insulation & the dpm.The slab is prevented from touching the rising walls by the 25 thick edge insulation (which also serves to prevent cold bridging) so the slab is completely independent of the main structure.The slab thickness is normally 150mm and should not be less than 100mm.

You would normally only need steel mesh reinforcement if the floor is suspended i.e actually bears onto the rising walls due to the hardcore being more than 900mm thick.

It can also be a good idea to use a layer of A142 mesh in the top of the slab if you are putting in UFH.This can help prevent cracking as the slab heats up and dries out.

It sounds like your floor slab is a floating slab so you should be ok.

Personally I would insist on a layer of A393 mesh in the bottom of house foundations.