HELP - What are GROUND SLABS ST3-OPC

[zappastix]

Hi

We are just digging the footings for a small extension.

Reading through the plans again it specifies;

GROUND SLABS ST3-OPC / 20mm agg.

What are Ground Slabs?

This is the full section;

New concrete foundations to be ST1-OPC/20mm agg plus ground slabs to be ST3-OPC / 20mm agg.

Solid ground floor to be 100mm blinded hardcore . . . . .

Do we make these ground slabs on site when the delivery truck arrives or do we purchase them.

Just to let you know the property is on reclaimed beach so very sandy.

Many thanks.

Stephen

 

[comparethebuildingmateria]

Hi, i have been a grounworker for a number of years and i have never jeard the terminology "ground Slabs", the footings detail is correct and also the make up of the oversite is right, but ground slabs??????? sorry cannot help

 

[zappastix]

Thanks anyway comparethebuildingmateria.

 

[^woody^]

Surely if you have some drawings, it will show what ground slabs are on them? It seems like some standard specification text, so check the plans to see if any are actually in your project

Normally these will be a big slab of concrete acting a foundation or a raft or suchlike

 

[r896neo]

Is it an abbreviation of ground floor slabs as in the concrete subfloor? I'm sure you knew but though i'd mention it in case but the ST1 OPC 20mm is a concrete spec as in St1 (something like C20 if i remember right) ordinary portland cement and 20mm stone.

 

[Static]

Urm i thought ST1 was lean mix.. which is something like C7.5.. not really to be used in a structural capacity.. should only really be used for non structural fill..
You should contact your drawing designer for confirmation of what ground slabs refers to.. but chances are it is for the ground floor slab..

You should consider upping the foundations to ST2 or ST3

 

[r896neo]

Oh sorry, just looked it up static is quite right. I was thinking of st4 being about C20. Yes st1 is as static said pretty lean and not really foundation material.

 

[zappastix]

I've just spoken to the Chartered Surveyor who provided the plans (a few years ago), he didn't really remember why he said ground slabs.

So now I have just got to order strong foundation mix via a truck.

Thanks for every ones help.

I'm sure I'll be back.