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[cAtLeYx]

noseal, With all due respect, I did not say you don't construct the inner leaf - I said you leave the DPC exposed (i.e., hanging over the sub-structure brick/blockwork on the inside) you then construct the cavity wall, roof, windows etc until wind & watertight. The previously installed DPC is then able to lap over the DPM when the structure is watertight and the oversite is not puddled with water and exposed to the elements.

 

[Donnapaddy]

They stood on it and it cracked ,I suppose because the polystyrene insulation has hive in it ,it rained heavy the night they put it down.and new regs say you have to put selatex along the damp proof ,and I think water got down the sides of this to the underneath ,as concrete will not seal to the selatex insulation

 

[noseall]

noseal, With all due respect, I did not say you don't construct the inner leaf - I said you leave the DPC exposed (i.e., hanging over the sub-structure brick/blockwork on the inside) you then construct the cavity wall, roof, windows etc until wind & watertight. The previously installed DPC is then able to lap over the DPM when the structure is watertight and the oversite is not puddled with water and exposed to the elements.

Yes that will work as long as everyone tiptoes around the polythene for the next two months. How does this method work when a troweled slab is specified i.e. power floated slab whereby the tamping process uses the masonry as a guide and the power float needs to overshoot the masonry?

 

[noseall]

Oh, and how do you get the concrete in?

 

[cAtLeYx]

Yes that will work as long as everyone tiptoes around the polythene for the next two months.

noseall - You have no idea - There is no "polythene" - The Damp Proof Membrane is laid on top of the oversite once the structure is complete.

How does this method work when a troweled slab is specified i.e. power floated slab whereby the tamping process uses the masonry as a guide and the power float needs to overshoot the masonry?

A power floated slab is a whole other subject. Its still gets laid after the structure is watertight. A laser level is used to level the surface and the power float polishes the surface once curing commences. (Hydration)

Oh, and how do you get the concrete in?

The "concrete (Oversite) is cast on completion of the sub-structure...... Give me strength.

 

[noseall]

The "concrete (Oversite) is cast on completion of the sub-structure...... Give me strength.

What, through one of the windows? Yes, you would need plenty of strength to get that lot through a window.

You intimated that this is normal procedure for (domestic dwellings) builders. It is not. Factories yes. I have never seen a housing estate whereby the slabs are cast after they put the lid on and all the windows in. Have you?

Yes it is possible to cast the slab later on but it is not the sensible or practical way to build. The OP's case is unfortunate but difficult to avoid under the circumstances.

Why was the DPM and insulation laid before the structure was wind & water tight. There would be no benefit to the sequence of works. The insulation and DPM should be removed and only installed when the structure is enclosed.

It is you who have no idea boyo.

 

[Donnapaddy]

Can this not turn 8n to a argument as a complete novice I am just looking for the right advice thanks

 

[noseall]

Can this not turn 8n to a argument as a complete novice I am just looking for the right advice thanks

The slab should not move once laid. The water will dry out but may leave a void. Small amounts of water will have no consequence to the slab. It won't matter a jot if the slab gets wet after it is laid. It will dry out once the roof is on.

 

[noseall]

id be more worried as to why it cracked the next day, water doesn't crack concrete

Me too. Trés bizarre.

 

[cAtLeYx]

What, through one of the windows? Yes, you would need plenty of strength to get that lot through a window.

Read my the item again - I said Sub-Structure for your clarification the sub-structure is from top of foundations to DPC - Therefore you have no Super-structure constructed yet to

get that lot through a window.

You intimated that this is normal procedure for (domestic dwellings) builders. It is not. Factories yes. I have never seen a housing estate whereby the slabs are cast after they put the lid on and all the windows in. Have you?

Again read my comment again. No you are correct, "I have also never seen a housing estate whereby the slabs are cast after they put the lid on and all the windows" This is because the slab (Ground bearing) is cast on completion of the Sub-Structure..!

Yes it is possible to cast the slab later on but it is not the sensible or practical way to build. The OP's case is unfortunate but difficult to avoid under the circumstances

I have never once suggested in any of my comments above that the slab should be cast after the Super-Structure is complete.

It is you who have no idea boyo.

Below is the the correct sequence of works
1. Remove topsoil
2. Reduce level dig - This will be to the underside of the type one stone. (Formation Level)
3. Excavate foundations
4. Cast foundations
5. Construct sub-structure blockwork to DPC level
6. Install cavity fill
7. Back fill foundation
8. Lay and compact type one stone
9. Cast ground bearing slab
8. Install 200mm wide DPC to the inner leaf. 100mm on the bed joint and 100mm hanging over the inside.
9. Construct Super-structure
10. Construct Roof & Coverings
11. Install windows and doors.
12 - Wind & Watertight (Milestone)
13. Lay 1200 gauge Damp Proof Membrane over the previously cast ground bearing slab, lap perimeter up under the previously installed DPC and seal joint
14. Lay ridged insulation (This is the item the OP has advised that is being installed now prior to wind & watertight).
15. Lay screed

Perhaps you could review the above, advise on what sequence you would change and confirm what the advantages would be.

 

[Donnapaddy]

The have put the damp proof membrane down and first layer of concrete then they have started breeze blocks half way up now .this is why it's getting filled with water

 

[cAtLeYx]

Can you reconfirm your first post that the water is pooling under the insulation. Has the DPM and insulation now been removed?

 

[Donnapaddy]

Hi yes the water was on top of the membrane when they broke the section of cracked concrete up ,we mopped the water up he then put new block of insulation down and re concreted that bit .but before he done that the water was seeping onto the membrane from the rest of the floor so I assumed water is still under their .he said it will get ducked in to the concrete and dry out .also the damp proof membrane is cut off at the height of the selatex round the edge ,should it be loose or fixed to the bricks .I've tried to show it in the pic .thankyou

 

[kazuya]

cAtLeYx without wanting to get involved in any arguments if you read the OPs first post, they are going with DPM, insulation, concrete then im assuming screed, not DPM, concrete, insulation then screed. Never done it that way myself but it seems acceptable.
Anyway regardless of that i dunno how many sites youve been on, but on the ones ive been on the only part of the floor that gets done after the buildings up is the insulation then screed, excepted sometimes on large steel framed buildings.

OP it might take a while but the floor will dry out, Im just a bit confused as to why the slab cracked, you can normally walk on concrete the next day with no problems, is your builder a large gentleman lol

 

[Donnapaddy]

The foreman is ...so should it have been concrete as first fix.then when roof etc is on and windows they then put insulation down and concrete then the screed ...also does the screed need time to dry before wood or lamminate is put down .thanks for your help