Cold bridging on internal block wall

[LaChab]

Hi,

 

I'd welcome thoughts on how to start my internal load bearing walls.

 

I'm sure it must have been covered before, but I can't find anything that exactly covers it.........

 

My ground floor internal walls are going to be built up from the ground bearing slab.

There's going to be 300mm of insulation on top of the slab, so the floating floor will finish up 300mm up the wall.

 

So the cheapest answer seems to be just to use lightweight blocks, which I think will give an R value of about 0.6 at 300mm high.

 

Or I could add  a row of Marmox Thermoblock, which would give R of 2. But cost another £600.

And if I did that, perhaps I might as well use concrete blocks, which I'd prefer.

 

Does anyone know how to calculate what the potential heat loss is from a 9.0m 100mm wall resting on a ground slab?

 

I just can't decide if the extra cost is worth it..........

 

Thanks for reading.

[Dave Jones]

ideally you should be using marmox on the inner skin all way round anyway.

[LaChab]

ICF outer walls, so they're sorted, but I realise a good idea for these.

But even the Marmox only give a U of 0.5, so how much will I save for quite a lot of expense?