Cavity wall insulation removal advice please
I would really appreciate some guidance on my current cavity wall insullation issue at my home please. Just wanting to get second opinions on my options & see if anyone has been in the same boat.
So the flat roof on my two storey rear extension has some damage from wear & tear (it's quite old & I should have replaced sooner) anyhow water has got in and gone down one of the cavity walls which is insulated with rock wool the nasty yellow stuff. I've had a camera put in there & it's soaking causing damp in my kitchen & wet walls in my bathroom. I am patching the roof up for now & replacing when the weather breaks, but my question is do I need to remove the wet old insulation or will it dry out? My kitchen & bathroom are always cold so I feel they need the insulation but I had professionals around who said it needs to come out to the tune of nearly 2k. Whats ur thoughts do I pay to remove because it's old & damaged? Or do I leave to dry out? Do I consider replacing? And once I take the roof off will I be able to access to remove or do I absolutely need professionals to get it out? Any help & guidance would be appreciated, thanks
Advice from 3 local tradespeople
You need to remove the insulation if it has got damaged 2k charge depends on the m2 of the extension rule of thumb about £25 m2
Wet rock wool insulation won’t dry properly in the cavity it should be professionally removed to prevent ongoing damp and heat loss. Once the roof is fixed, you can consider replacing it with a moisture-resistant option. DIY removal isn’t practical and specialist equipment is needed.
You need to remove the wet old insulation. It won’t dry out properly inside the cavity and will likely lead to ongoing damp, mould, and heat loss if left in place.
Yes, you should pay to remove it. Since it’s old, water-damaged, and no longer effective, it’s not providing insulation anymore and may be making the cold worse by holding moisture. Removal is the right step, even if it's costly—it protects your home long-term.
Leave to dry out? – No, it won’t dry properly inside the cavity and can worsen damp problems.
Consider replacing? – Yes, after removal and roof repair, replacing the insulation will help with warmth and energy efficiency.
Access to remove after taking roof off? – Partially, but you likely won’t reach all areas effectively.
Need professionals to get it out? – Yes, full removal usually requires specialist tools and methods, so professionals are strongly recommended.
