screed or concreting my floor

[ambercelery]

I want to level my kitchen diner - and having removed the old quarry tiles from the old kitchen revealing the old concrete base, the flooring is about 10mm to 20mm deeper in the old kitchen,
There is also a small hole which has allowed me to peer underneath the existing concrete base - and there is a cavity betneath the concrete of about 5 inches.
What do i need to do in order to relay and level the floor?
I couldnt see any sign of damp proof membrane - should i put down a plastic damp proof membrane before i put new concrete down?

Am I ok - just to build up the exisiting floor by the required 10mm-20mm with concrete (sand 3:1 cement) - or do i need something else?

If i was to use Damp proof paint i.e. Bitumen paint - should i paint this before i put the concrete down, or on the top coat, or both ???

Cheers

 

[noseall]

[quote="ambercelery";p="871829"

the flooring is about 10mm to 20mm deeper in the old kitchen,

by this, do you mean that the difference between the floor heights is 10-20mm and that the floor in question is LOWER?

There is also a small hole which has allowed me to peer underneath the existing concrete base - and there is a cavity betneath the concrete of about 5 inches.
What do i need to do in order to relay and level the floor?

i'm not really getting this bit. do you have a block & beam floor?

I couldnt see any sign of damp proof membrane - should i put down a plastic damp proof membrane before i put new concrete down?

it will depend upon your answer to the previous question

Am I ok - just to build up the exisiting floor by the required 10mm-20mm with concrete (sand 3:1 cement) - or do i need something else?

10-20mm doesn't allow for a deep enough screed and is likely to cause problems unless additives are used in the screed. you are in that awkward thickness of being too thin for a standard screed and too thick for floor levelling compound.

Cheers[/quote]