Insulating a floor

[Peakdistrict]

I'm sure it's been asked before,but I couldn't find an answer when I tried searching.

We have stone flagged floors laid on earth. They are in good condition and level but I've been toying with the idea of lifting them to add some insulation.

Whats the best aproach to doing this? Can I just add a sub base of stone compacted, kingspan or similar insulation, sand screed on top of that then relay the flags dry onto that? Or do they need crementing in place?

 

[a twig]

For me you’d be at the risk of causing/exacerbating damp problems by doing anything like that,

Unless other more learned members of this parish have had better experiences your only option in my opinion would be limecrete with LECA etc then relaying over the top with a lime based mortar

 

[a twig]

Or leaving it as it is and investing in hessian / sisal based rugs / carpet. there’s a thread somewhere on that very topic

 

[Peakdistrict]

For me you’d be at the risk of causing/exacerbating damp problems by doing anything like that,

Unless other more learned members of this parish have had better experiences your only option in my opinion would be limecrete with LECA etc then relaying over the top with a lime based mortar

Thats my concern. I recently lifted to 1970's bitumen that had been poured over to level it out and thus caused damp to move into the walls instead. Thankfully whoever did it used a membrane between the flags and bitumen, so it came up easily with no cleaning required. But it's very drafty beween the flags somehow and just generaly cold under foot even with shoes on.

 

[88v8]

it's very drafty beween the flags somehow and just generaly cold under foot even with shoes on.

What... wind coming up from the floor? Maybe you have a dragon.

Presumably the house has no dpc in the walls so as you say one has to be careful not to send damp into the walls by using Kinspan or suchlike impermeables.

A limecrete floor would be a bit warmer, the main advantage is that the floor would be dry which your flags may not be at present. Damp does leach away heat, so just having a dry floor would make quite a difference.
At the same time you could consider underfloor heating, if you want to get into such complexifications.

A simpler solution might be furry slippers.

 

[Peakdistrict]

What... wind coming up from the floor? Maybe you have a dragon.

Presumably the house has no dpc in the walls so as you say one has to be careful not to send damp into the walls by using Kinspan or suchlike impermeables.

A limecrete floor would be a bit warmer, the main advantage is that the floor would be dry which your flags may not be at present. Damp does leach away heat, so just having a dry floor would make quite a difference.
At the same time you could consider underfloor heating, if you want to get into such complexifications.

A simpler solution might be furry slippers.

Furry slippers are already well used here!

Not sure why theres a draft up through the floor, but there are drafts in almost every crack, window and skirting board too. The joys of an old house.

Underfloor heating is out of the question due to running costs. I can imagine it would be the best way to heat downstairs, but with the current price of oil and 2 family members working from home 4 days a week, I can see it being on constantly.