Hi 

 

I am planning our renovation starting in the next couple of months or so

 

I started another topic regarding my new concrete floor make up, currently my property is joisted and floor boarded with a decent sized void beneath (need to take measurements once flooring is up)

 

The planned make up is: 

 

200mm Type 1 MOT

50mm Sand Blinding

150mm Concrete slab

200mm PIR insulation

UFH Pipes

50mm Screed

 

So total depth around 650mm, there is 2 DPM layers also

 

Some comments and research have suggested their could be better ways to do this but i can't find a definitive answer

 

I would really appreciate some advice/information and some potential floor make ups, We will be using wet UFH with ASHP for heating throughout

 

Thanks in advance

 

 

50mm of screed is very little if this is to be a low energy dwelling. To take advantage of different types of energy consumption and to maximise efficiencies, I am always an advocate of a bigger slab so you can store slow release heat energy in it. I would dial back the type 1 to 150mm depending on how much you 'need', reduce the sand blinding layer to 20-30mm, install a sacrificial 25mm EPS layer atop the sand, and then the DPM. 

That would allow you to get closer to 80-90mm of screed which will then act more like a storage heater than a radiator.

 

In absolute honesty, I would flip the whole lot on its head if it were my place, and have the 150mm of concrete as my heated ( and cooled ) slab with the insulation atop the type 1. 

You say :-

200mm Type 1 MOT

50mm Sand Blinding

150mm Concrete slab

200mm PIR insulation

UFH Pipes

50mm Screed

 

I would go thinking top down :-

 

75mm Screede, 150mm concrete, dpm/vb, 300 EPS, no sand blinding compacted recycled crushed concrete.