How do I insulate under old cottage floor - and should I?

[tidgecourtier]

I'm in the middle of a cottage restoration and seem to be receiving lots of conflicting advice. The ground floor cottage has old floorboards. In one room there has been some remedial work and concrete has been put under the floor - still with joists and suspended floor. In the other room there is simply earth under the joists and floorboards. Please help - should I put down a damp proof membrane here and then insulate with rockwool or similar between joists, or will introducing a damp proof membrane trap moisture and therefore create condensation. Please could anyone with similar experience advise. Many thanks.

 

[mointainwalker]

In the other room there is simply earth under the joists and floorboards

Are the joists sitting on the earth or is there a gap ? If so, how much ?

 

[tidgecourtier]

Thank you very much for your reply. The joists sit on stubby lines of bricks and then obviously the floor is attached to the joists. There is approx 8 inches between earth and timber floor.

 

[mointainwalker]

I do not believe a membrane is necessary. Lift the boards and support the fibre-wool on chicken-wire or similar between the joists.. The underfloor should be vented by air-bricks to keep air dry.

 

[tidgecourtier]

Thank you so much - what a great tip, the chicken wire, that is.
I shall definitely do that - renovating seems to be a very steep learning curve - just too many decisions!

Many thanks