Cold bridging / insulation

wersal gummage

Hi folks,

Possibly over thinking this but have seen this concept of cold bridging etc and can't really say I understand it and whether I need to take it into account here.

I've removed an external vent cover and removed an old fkexi ducting pipe. I'm replacing with rigid ducting. All fine. Only query I have is that basically the "hole in the wall" is massive, a good square foot, and inside that hole there's a lot of empty space before I hit a dedicated ducting tunnel, when I install the new duct I'm left with a massive kind of empty space inside the external wall. So this was always like this I just didn't know about it. Just wondering before I close up a new vent, should I shove a bit of earthwool or the like into the hole? Not sure if I'm then causing issues with hot or cold bridge or I even need to look into this?

Thanks for any suggestions

dbas

https://www.boards.ie/discussion/2058342393/cold-bridging-insulation

Hi

Can you share a photo of this.

From outside looking in, and inside looking out?

thanks

10-10-20

https://www.boards.ie/discussion/2058342393/cold-bridging-insulation

Sounds like it's a basic cavity wall and you've discovered the cavity itself between the inner and outer leaf.

A photo will confirm this, but you would normally back-fill the hole in the wall with a mortar mix, leaving only the vent pipe to bridge the cavity and with no mortar from the internal wall touching the external wall at all, or vice a-versa. Example in the image below where you can see insulation in the cavity and the cavity is not otherwise bridged.