Cavity wall or insulate?

[camerart]

Hi,
I have a cold corner of my house, northerly aspect. It used to be an outside toilet, and coal shed.

I'm thinking about knocking the walls down and changing them to cavity wall, and realised that the footings would need to be wider, then I got a thought that I could insulate the inside with 'say' 2inch foam insulation instead.
Is this a good idea?
Cheers, Camerart.

 

[phatboy]

Should work, loads of info on here about methods.

Or you could insulate it externally, and then it would get a nice new render coat too....

 

[Wayners]

I heard about spray cork insulation recently that might be worth considering

 

[camerart]

I heard about spray cork insulation recently that might be worth considering

Hi W,
I've been seeing a bit about spray insulation, and it needs caution.
Thanks,
C.

 

[camerart]

Should work, loads of info on here about methods.

Or you could insulate it externally, and then it would get a nice new render coat too....

Hi P
External may be a bit difficult, and to match the rest of the house would look a bit out of place, against nice red bricks.
I'll look into internals a bit more.
Thanks. C.

 

[camerart]

Hi,
I'm going to add a damp membrane to the solid wall, fixed with battens, then add 75mm insulation and plasterboard.
I'm going to check how to do all of this, but if anyone has a link, will you post it please?
C

 

[mrrusty]

My solution. Other suggestions may differ.........VCL goes on the room (warm) side. Build an insulated stud wall with a cavity to the brick wall. Stick an airbrick in the external wall to ventilate the cavity behind the insulation. Result - same construction as a timber frame house. The ventilated cavity will keep it dry should any condensation form in it. On the cold side of the insulation you could/should also add a breathable membrane. I would aim for 75-100mm insulation - you'll sacrifice a little room space, but it'll be much warmer.

 

[camerart]

My solution. Other suggestions may differ.........VCL goes on the room (warm) side. Build an insulated stud wall with a cavity to the brick wall. Stick an airbrick in the external wall to ventilate the cavity behind the insulation. Result - same construction as a timber frame house. The ventilated cavity will keep it dry should any condensation form in it. On the cold side of the insulation you could/should also add a breathable membrane. I would aim for 75-100mm insulation - you'll sacrifice a little room space, but it'll be much warmer.

Hi R,
This is very similar to what I intend to do in last post.

The membrane goes aginst the solid wall, with drain vents at the bottom for moisture drainng, held on with battens, which is an inch cavity, then foam insulation is screwwed to the batten.
All passed by building control, so I'm not thinking anymore.
Thanks, C.