concrete flooring

[diy001]

Can someone advise me re concrete flooring please. The ground i propose to build my extension off is currently concreted. It is below the internal floor level but not sure if it is low enough to lay the 50mm sand, dpm, 50mm insulation, 100mm concrete, 25mm screed. As you'll understand i want the floor to be level with my other internal floor levels not higher.

I'm guessing the current difference is around 15cm max. I will check this when i get home and will post exact.

If it is 15cm could i get away with not digging up the floor by minimising the upper layers of flooring. i.e sand concrete screed.
I just want to be sure. many thanks.

 

[diy001]

surely someone must be able to help me on this.

 

[freddiemercurystwin]

Only joking!

 

[Norcon]

Forget about the 50mm sand. You don't need that.
Go for 75mm insulation and 75mm fibre screed.

 

[diy001]

Norcon are you saying, i should leave the origional concrete base,
1, lay DPM
2, lay 75mm isulation
3, lay 75 fibre screed
and job done.

I was working off this

http://www.lets-do-diy.com/Projects-and-advice/Concrete-work/Laying-a-concrete-floor.aspx

 

[diy001]

Only joking!

Hi FMT, how you doing.

 

[Norcon]

are you saying, i should leave the origional concrete base

Depends.
If its top soil below then dig it up.

 

[diy001]

norcon what do mean top soil? im

 

[Norcon]

The stuff in your garden which grows grass or plant vegetables in.

 

[diy001]

i know what soil is i just just know what you mean.

Currently there is a concrete floor of which i dont know the depth and im sure if i was to dig it up i would find soil.

What i need to know is must i dig the concrete up? if so please explain why.

I have 15cm from the concrete to dpc in which i could insulate screed dpm sand whatever.

Is that enough space for me to lay a correct concrete floor without digging the concrete up?

http://--/Projects-and-advice/Concrete-work/Laying-a-concrete-floor.aspx

I just need it to be a little clearer, sorry.

 

[diy001]

guys i would really appreciate the advice!

 

[freddiemercurystwin]

Still joking!

 

[diy001]

I'm not laughing mate, if you not willing to contribute to advice then why you posting?

 

[freddiemercurystwin]

I'm sorry.

 

[wavetrain]

Don't be sorry FMT, this person claims to not know what top soil is in the building section of a DIY forum and also has a history of abusing forum members.