I have built a single-storey house, with the following principle: 20cm type MI335 cellular concrete walls from YTONG + placostil insulation with glass wool in 2 crossed layers of 60mm. I have a placo ceiling with wool blown above: - I wish to set up 400mm is it good, too much, etc...? - Then my shutter boxes are embedded in the walls so I would have a thermal bridge - How to fix or limit losses. - Last questions: I have a low temperature heating floor (heat pump) - The gain is really good if I put an extra insulation under the pavement (I solenoid vertical foundation to the underplating placostil). Regards,
The MI 335 block has been developed to meet the demands of individual home builders who want to limit the thickness of walls to the benefit of interior surfaces. It is obviously a good product, but I wonder about the contradiction of YTONG which has claimed on all the roofs since always that the cellular concrete of 37,5 or 50 of thickness has the advantage of being to pass of complementary interior insulation... and which proposes today the opposite. In this case, it would be necessary to compare the cost of a concrete block construction with reported insulation compared to an MI 335 wall.
For the thermal bridges of your shutters, I advise you to get closer to YTONG, because I have no information on this subject.
For your attic, 400 mm seems good.
Finally, it is clear that for your heating floor must provide insulation under slab.
Given what has happened this winter throughout France, I now advise to combine radiators or basic convectors to relieve the CAP in case of extreme cold (the cost is minimal).
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