Internal insulation query

[joelk2]

Backstory: I have a bedroom in my house at the back of the house which is incredibly cold in the winter and ridiculously hot in the summer. In the winter the walls feel very cold to the touch. The roof is inaccessible and sloped, when I was doing up the room I made a few holes in the ceiling and could see insulation in rolls in packaging within the room space.

If anything fabric is touching the walls for a while it goes mouldy, the walls can get occasional mould patches.

I'm suspecting water ingress is coming through the bricks?

Would some foil and insulated plasterboars make the room normal? Would I get mould issues and would that plasterboard be ok on the ceiling?

 

[joelk2]

Why is it you’re not able to access the loft?
It sounds like an insulation problem ie there isn’t much/any.
What age is the property?
Do you have any heating in it?

Have heating yes, radiator in the room.

Property is around 115 years old

No hatch, is the rear part of the house with a sloping roof. Hence wanting to insulate (even only a little) with the backed plasterboard.

Main part of the house large loft.

I don't think we have a cavity in this part of the house.

 

[joelk2]

If the room is part of the original house then they will be solid brick - one stretcher and one header - most likely for a house that is 115 years old.

If the room is actually an addition then, it may be single skin which is not only awful for insulation, is also fairly insubstantial.

Either way, you have solid/single skin walls with no cavity which are externally facing. So, when you place an item against these walls, the air temperature internally is much higher than the temperature externally causing condensation to build up on the internal face of the wall.

So, anything touching the wall becomes wet and begins to go mouldy.

That’s your issue. Insulating the roof will do nothing.

Best to keep items away from the walls - the only solution from that point would be some sort of externally applied cavity insulation or cladding

its deffo part of the original house so solid brick. my assumption was that a (as below) celotex type insulation with foil would stop thermal issues causing the condensation?

I had this exact situation.

I tore the roof down and found old insulation blocking airflow and evidence of old leaks (fixed by the new roof)
I carefully re insulated the roof and I have just battened the walls out with 50x50mm timber leaving a 10mm gap and filled the stud work with 50mm celotex.

Room is warmish (no radiator in it yet)

this is kind of what im thinking but without taring of the roof

 

[joelk2]

Yes that could work provided you can loose some room space?

I'm willing to sacrifice some room space, (2 walls are externally facing) so wouldn't be too much of an issue.

Currently my 2 daughters are sharing a room and the small cold room is a dumping ground/occasional room but don't fancy letting one of the girls have it as a full time bedroom with potential mould issues.

 

[joelk2]

Or you could externally insulate the walls and render. This is quite a common method of improving properties insulation where it is not possible to use an internal solution.

External is a no go Due to being a conservation area