Help with cracked 1st floor wall

[Dimias]

I have a two storey extension that was done to my house well before I bought it (at least 12 years ago).

On the first floor there is a crack on the side wall both exterior and interior. It is plaster-breeze block-pebble dashing. Interior it just runs along the corner. Exterior crack is about 2m in length, about 3cm wide in widest point but most of it it is 1-3mm wide. There is no sign of any issues on ground floor.

Insurance company arranged a video call with building consultant who concluded that it wasn't subsidence and nothing covered under insurance, he said it was very slow movement of the side wall pushing against the back wall. He verbally said to me he would just peel back the plaster, repair the cracks from inside, put some metal supports in place then re plaster. Outside is in a really awkward position to get to.

I've now had a builder round to quote for the work and he's said he can do the inside only but would recommend doing outside as well and it should be covered under the insurance.

This has left me a bit confused what to do.

So my question is do you think it's worth just doing the inside? Or am I just going to get into issues again in a couple of years time.

I've attached some pictures as well.

 

[^woody^]

It does seem indicative of thermal movement of the wall panels, rather than foundation movement. Are you sure that it is not covered by your policy? Building consultants employed by insurers are not impartial and should not be determining the policy cover, just advising on building matters.

It does need repairing from both internal and external, but firstly the actual cause needs to be determined and confirmed that the movement is not ongoing. Only then can the correct repair be devised and carried out.

 

[A Trowel]

it was very slow movement of the side wall pushing against the back wall

Seriously that is that supposed to mean ?
Tell your insurance you’d like a site visit from a structural engineer not a video call for someone with a made up job title

 

[KenGMac]

Problem is that the "Insurance" definition of Subsidence is simple, it is ---the downward movement of the foundations---

If you have no indications of crack damage within the ground floor wall then ???

The upper floor damage will be called by your Insurer as a "Lateral Stability" issue where the exterior wall is [obviously] seen to part company from a gable? wall??

As for repair, check out the various systems in "Helifix" they can restrain a corner by boring in and fitting thin spun steel bars, it works, i have specified such systems on several occasions, both for exposed external corners and also internal walls to external walls, a very versatile and clever set of options.

Ken