New concrete floor in 1890's terraced house, advice please.

[Dahermit]

Hi,

I am working on replacing the old tiled floors in my mums house with a new concrete one. Having tried to research what I need to do in order to ensure the new floor is safe and also complies with building regs, I have come up with a sort of specification which I was hoping the experts around here would cast an eye over and let me know if its ok, or make suggestions on things I have got wrong.

OK, so the plan is to do the following:

Layers in order from the top down.

Concrete - 100mm
500guage polythene
Celotex GA4090 insulation board - 90mm
DPM lapped into walls.
sand blinder - 50mm
Well compacted aggregate - 100mm

I will also be putting celotex TB4020 boards around the edge of the slab to insulate the edge.

Like I said, any suggestions/advice verfy much welcomed!

 

[freddiemercurystwin]

Sounds good to me.

 

[theoldun]

Hi,

let me know if its ok, or make suggestions on things I have got wrong.

Like I said, any suggestions/advice verfy much welcomed!

No one can say whether your spec is any good without stating your P/A.
Assume you are looking for 0.22W/m2K.
Unless you are a real dab hand at finishing concrete and can lay a perimeter concrete dead-man, then you are better to finish with a screed.
oldun

 

[jeds]

I'd be careful. Your mum's existing floor is most likely a breathable material - some form of old limecrete or similar - and installing a sealed concrete floor might cause you dampness problems. What sort of walls do you have and how well drained is the surrounding land?

 

[Dahermit]

Hi,

let me know if its ok, or make suggestions on things I have got wrong.

Like I said, any suggestions/advice verfy much welcomed!

No one can say whether your spec is any good without stating your P/A.
Assume you are looking for 0.22W/m2K.
Unless you are a real dab hand at finishing concrete and can lay a perimeter concrete dead-man, then you are better to finish with a screed.
oldun

I have worked out a P/A of 1.16 for one area and 0.29 for another area.


Thanks for your reply btw!

 

[Dahermit]

I'd be careful. Your mum's existing floor is most likely a breathable material - some form of old limecrete or similar - and installing a sealed concrete floor might cause you dampness problems. What sort of walls do you have and how well drained is the surrounding land?

The old floor was made of tiles laid on top of compacted clinker or slag it looked like, the tiles were mortared in. It is pretty damp, we are also doing a damp proof course in the walls while we are doing the plastering etc. The walls are standard brick, solid walls no cavity. No DPM either obviously, just engineering brick layer.