Insulating internal wall which is currently open to the cold loft

[StephenStephen]

Hi all,

We've a couple of rooms that are always cold.

Having a lath and plaster wall which is internally open to the cold loft probably doesn't help!

What is best to fill this space with?
Can I seal up the top with expanding foam?
Do I need to be concerned about condensation?

The first photo is looking horizontally at the top of that internal wall as it extends above the room into the loft
the second is looking vertically down from the loft into the wall

Thanks for any ideas, cheers, Stephen

 

[Tigercubrider]

I'd see if I could find any large bits of polystyrene as I am a tightarse.
loads of people are having a new telly for xmas so there should be a fair bit.

or use expanding foam
Read the instructions and be careful as it doesn't stop expanding for a while
maybe shape a bin bag in the top of the wall so that you don't fill the cavity

 

[StephenStephen]

I'm thinking that i probably do want to fill the cavity? (but with what?)

 

[Tigercubrider]

You could use chopped rock wool ? Not sure if it is still available but you used to buy it in sacks to rake over a loft. Just pour it down and maybe use a stick to ensure that it doesn't stick and block up

Or polystyrene balls?

Cavity batts are often used but you'd need to check that the width/ thickness was suitable for the cavity

 

[Ian H]

Pour in those little insulation balls?

POLYSTYRENE BEADS / BALLS POLYTERM BLU INSULATION CAVITY WALL ETC https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/223277863883

I can’t imaging you being able to get a good fit with anything rigid.

 

[John D v2.0]

pouring in balls would surely be a disaster, unless the void is perfectly closed everywhere they'll end up somewhere they shouldn't! In cavities they pump them in with glue to try to stop them falling everywhere. The wool would make more sense.