Underfloor Heating

[harkerhill]

Hi

I've decided to try to get a ground source heat pump working in my house due to the ever increasing fuel costs.

First step is underfloor heating.

This means removing the existing concrete floors, and constructing the floor with (lowest level first)

100mm dolly
DPM
100mm concrete
100mm kingspan insulation
then the ufh pipes
then 65mm screed over the top
(might go for 45mm screed and 20mm slate floors)

Obviously this floor isn't going to be able to breathe, but does that mean that the walls below the DPC will be more damp ?

Will the above cause any problems, or should I change my plan with the construction of the floor?

Any advice would be greatly appreciated.

 

[biffvernon]

Delete concrete, insert limecrete - that's Light Expanded Clay Aggregate (LECA) and lime.

 

[harkerhill]

Delete concrete, insert limecrete - that's Light Expanded Clay Aggregate (LECA) and lime.

But won't the DPM or the foil on the insulation or even the insulation itself act as a membrane for the damp?

 

[NT]

An idea those with more experience could comment on: use a concrete floor, but fit triangle profile wood round the edge before pouring the crete, and once set fill in the triangle with a lime based mortar. You get the concrete floor but the lime area in contact with the walls enables them to evaporate dry.

___________________ floor level
w | /
a | / <-- that bit lime
l |/
l | concrete




If pasted into non-proportional font it'll look clearer, eg notepad.


NT

 

[biffvernon]

What's the point of a concrete floor - other than to speed global warming on its way?

 

[harkerhill]

What's the point of a concrete floor - other than to speed global warming on its way?

A concrete floor is the most efficient for UFH. UFH is suitable for GSHP's which are more efficient than gas, oil etc.... sounds like a way to help with global warming to me.

 

[biffvernon]

What advantage does concrete have over limecrete? (Other than short term monetary cost.)

 

[harkerhill]

What advantage does concrete have over limecrete? (Other than short term monetary cost.)

Just not sure on the point of limecrete if I am putting in insulation (foil backed) and a DPM... I know I can miss out the DPM but then what about the insulation? - wouldn't want to warm up mother earth with the UFH and keep me cold.

 

[Nemesis]

Talk to Ty Mawr about the lime/glass aggregate floors they provide the raw materials for before you go the concrete route.

http://www.limecrete.org.uk/