Conservatory dwarf wall sunk / dpc issue

[los]

Hi, after some advice on how to deal with an issue where it seems that the lower part of the dwarfwall on my conservary has sunk and separated at the dpc leaving a very large gap on both external an internal walls. The air gap is about 1.5cm at the largest tapers down for about 7ft of the length of the 10ft wall on both external and internal walls. This largest air gap is where the conservatory meets the house wall and tapers as you move away from the house wall. I guess the wall bracket is supporting a lot at the moment as the air gap is on both internal + external conservatory walls. Maybe relevant info is that there is a cavity of 5cm between internal and external conservatory walls which are both brick.
The conservatory is quite old, way more than 10years, and I'm pretty sure that this is something that's happened in the past quite some time ago and the base is no longer moving.

So far I have started working on the external wall only by cleaning both dpc sides, yes really, along with brick surface above/below as far as I can get. I have also used a small amount of silicone beneath the dpc to hold it in place as it seems mortar was only used above the dpc.
I have partially filled the gap with a 4:1 mortar to an approx depth of 5cm but leaving the end close to the wall open at the moment before I fill it with mortar after deciding best approach.

I have attached some images giving an indication of before and current situation.

So, is 5cm of mortar depth enough given that the bricks are 10cm in width? my concern, after supporting the wall, is for damp/moisture.

I intend to chase out the vertical mortar when the conservatory joins the house wall and replace with fresh mortar, but would it be a good idea to pump some expanding foam in there to reduce moisture/damp transmission? Would I need to be avoid bridging the internal/external wall cavity?

Also, I'm thinking that I could use the expanding foam trick on the internal conservatory wall to attempt to get to the parts of the brick/dpc unreachable by mortar? This might also allow me to get to the external conservatory wall dpc to provide a better 'seal' on the dpc.

Any advice would be greatly appreciated.

 

[Ivor Windybottom]

It's probably built on topsoil, as is common for conservatories. So it won't stop moving every time a twig rots or a worm digs a tunnel under it. If you fill it with foam, mortar or magic dust you'll probably just get another gap appearing under it.

Is it worth worrying about? It might be better just to relax and let it develop. If the wall falls down then build a new one or replace with a proper extension, this time with some foundations.

Expanding foam might help though, just mask with lots of tape and polythene to prevent all your bricks becoming a giant sticky mess.

 

[Ivor Windybottom]

Actually I'd chip out all the pointing then use a mortar gun to refill it. Do it alternate lengths at a time though, to prevent collapse. You never know, it might have done all the sinking it wants to.

Roughneck Mortar Gun Kit - Screwfix

 

[noseall]

It's probably built on topsoil

Standard connie foundation.
I'd fill with foam for a the good it will do.

 

[los]

Thanks for all for advice - I think I will add some mortar where I can for support before I chase out verticals at the house wall.l, and try to fill the rest with expanding foam, and check it next year for movement. Had some survey done which said it was causing damp ingress into the house, but given it's almost detached not sure how really - thought it might be related to the wall brackets.

 

[^woody^]

The issue is whether is moved, or is moving.

If the former just point and seal things back up and don't make a meal of it.

If the latter, you need to determine why its moved and either deal with arresting that, otherwise its no use filling any gaps.

 

[Ivor Windybottom]

...and if you start thinking about remedial action on a conservatory then weigh up the expense and time against how bothered you actually are about it. Most people don't really use them, so it could be ignored or replaced instead.

I don't get how it could cause damp, unless there's an issue with the roof flashing against the house wall.