Choosing the Right Type of Foundation

Slab vs. vide sanitaire? Discussion here along with info on how to layer with the moisture barrier and insulation.

https://www.ecohome.net/guides/2370/slab-on-grade-or-foundation-and-basement/

Some other useful articles here:

Tips from these pages:

  • Dig out the earth and then pack it tightly before pouring any concrete.
  • You can – if you’re crazy enough – do this without using any rebar (as if!)
  • You can literally make it up as you go along. These guys used rockwool under the slab and EPS under the footings. How does that not compress when under concrete and with the weight of the house on it. 
  • It IS important to use a Radon/vapour barrier before pour cement.
  • Remember to put the rebar over the vapour barrier!
  • Polished concrete is a good idea – but who is capable of doing this here in France?

Floor insulation

A good video on youtube about how to insulate a floor. 

Insulation a floor
( Poser un plancher isolant thermique)

Website to calculate how much 100mm flooring I need.

Calculation

Shopping list

The price here comes in at about 50 euro/m sq = 3150 euro


Alternative cheaper product

Recticel
Bricodepot.fr

This is Recticel FitForAll and here it’s sold in 30mm and 60mm sheets. But they are available up to 100mm (30mm, 40mm, 60mm, 82mm & 100mm) according to the Recticel Site 
Lambda 0.023

This would result in a cost of 945 Euros for 7m x 9m (15 euro TTC / m sq) 60mm sheets


From the following site, 100mm sheets are available for 28 euro / m sq (= 1764 euro for 7m x 9m)
https://thyez.entrepot-du-bricolage.fr/pr-dalle-isolante-polyurethane-fitforall-120×60-cm-epaisseur-100-mm-recticel-matc09-963844,31224,29,444.htm


Celotex

GA4090 ( 1 304,52 € for 69.12m sq ) 90mm sheets 
Lambda 0.022 Watts per mK
R value  4.05

http://www.isolation-pas-cher.com/catalog/category/view/s/isolation-plancher/id/17/?cat=135


Wood Fiber General

Not too good really, 4cm
R value 1.05

James

Wood Fiber Pavaflex Confort

Conductivité thermique : 0,038 W/(mK)
100 mm : R = 2,60 m².K/W
180 mm : R = 4,70 m².K/W
200 mm : R = 5,25 m².K/W

materiaux-naturels.fr
180mm boards are 18.75 Euro/m sq = 1181 euro for 63 m sq


Video on installing floor insulation


Under screed (on slab) possability.

This EPS is much cheaper than more promoted branded stuff and probably just as good. Here is a company in POLAND
https://www.matbay.fr/eps-toit-et-plancher-standard.htm

For example 64 sq metres of 20cm of this R6.45 (per 20cm) would be 817 euros.


Another good video on how to insulate the floor below. Has key details of where to put a vapour barrier – GRADE -> Gravel (with drainage) -> EPS foam -> Vapour barrier (also holds the foam down before 4″ of concrete is poured – > Concrete


Good video on insulation below slab from Kingspan

https://www.youtube.com/watch?v=-sc8y073RUc

Thin sand blinding to level ->appropriate damp proof membrane (well lapped and folded), should lap high enough to connect with, or form, the wall damp proof course -> eps at least 2cm thick vertical around perimeter, top should be level with top of the floor screed (damp proof course), layer and overlap eps -> overlap eps boards with polythene sheet (as a vapour control layer), make sure polythene sheet has 150 mm overlap

PDF details 
https://www.barbourproductsearch.info/Kooltherm%20K103%202nd%20Issue%20Aug%2016-file071371.pdf