Replacement kitchen floor slab

[adrianpettitt]

Hi,

 

I am renovating our 1930s semi, making the existing ground floor kitchen, dining room and lounge, into an open plan space. 

 

The kitchen floor is concrete, whilst the rest of the ground floor is wooden. Having taken up the quarry tiles I have found the subbase is very poor, very uneven and has no insulation, as you'd expect. So I am going to break is all out. BC have stated that I need;

 

150mm Hard core

50mm Sand

DPM

100mm Celotex PIR

100mm Concrete slab

65mm Screen

 

There will also be a Celotex insulation upstand around the external walls. I am also internally insulating the external walls as they have no cavity. So, to my first question: How thick should the PIR upstand be? As thick as the PIR on the walls?

 

Second bit of advice I'd like is on getting the new floor level. I've never done this before, so is a little daunting on how I mark the levels.

 

Thirdly, the Hardcore base has to be compacted, so which type of whacker plate do I hire? And does the blinding sand layer have to be compacted with one too? Is it the type used for doing patios or the type you see used at road works?

 

Enough questions for now.

Thanks in advance.

Adrian