insulating floors and external walls in existing house

[cake]

We are planning some house renovations to our 1950s built terraced house and are considering insulating the house, etc. We are considering these 2 items in particular:

1. Insulating external walls to the house. I think the external walls are solid, so I think the best option is to dry line with insulation board behind. Are other materials suitable (sheep's wool, etc.)? How much better would heat retention be if we also lined the walls with neighbours' houses?

2. Insulating floors. There is a gap, approx half metre under floor boards to a concrete base (a smaller gap in the kitchen extension). There is currently a draught from the floor - sanded T&G. How could the floor be insulated given this large gap? Would the floors need to be taken up?

Attic insulation is in place.

Any comments would be gratefully received.

 

[wexford dude]

Cake,

1 - the simplest way to insulate the inside face of your external walls would be to either dab on pre-insulated plasterboard or nail on battens and then your insulation & plasterboard.You will loose more living space with the second option.Kingspan provide both.
I don't think sheep's wool is a viabile alternative here.

2 - this depends on your desired finish and whether you are going for rads or ufh.The draughty floor means that there is plenty of air flow under your existing timber floor which is good.
If you intended to bring a concrete floor up to FFL (- depth for finishes) you could do the following:
- firstly inspect the sub floor to ensure that there is no subsidence issues
- Pour concrete to raise the sub-floor by 250 - 300mm.Make sure any toilet wastes, sink wastes run at this level.Place your dpm next.You may also require a radon sump in this for posterity.Then your insulation (Kingspan) whose thickness would determine the raised depth of the sub-floor.This leaves you with a 150mm floor slab.In this slab you would include your heating & water pipes.
The make-up would be slightly different for ufh.
- The alternative is to put dpm on top of existing sub floor.Make up level to underside of floor slab with aeroboard - 3 no. 100mm thick layers.
You then pour your floor slab.

 

[Damp Man]

Cake,

Use a wall coating on the external walls that will

1 Seal the walls against penetrating damp.
2 Allow the walls to to dry out.

Dry lining was designed only to conserve heat in rooms!