patching on reed and clinker blocks

[Cristian_lime_plaster]

Hi!, this is my very first post on this forum . I've been reading a bit, but basically I'd like to consult with you guys if you have better suggestions?

Background: I live in a flat in Oslo (Norway) on a 1930 flat, 4th floor (little humidity). When we purchased the flat, the walls had layers upon layers of wallpaper (including fiberglass wallpaper - common in here). After peeling the wallpapers, some plaster came off and we want to patch it.

Our goal is to patch the plaster, and then cover the walls back with fiberglass wallpaper (mainly because of durability). I'm aware that covering lime plaster with fiberglass wallpaper will revert all benefits of lime plaster (like 'breathability'). If something else rather than lime plaster can be used to patch the old lime plaster, then I'm happy with it.

We realised the room has 2 different types of walls (I have no idea why):

wall 1 'rabitzpuss': lime plaster over a reed mat, some animal hair for insulation (see pic 1). After removing the section, I can reinstall a reed section and plaster (see pic 2)

But on some parts behind the skirting area, the float coat came off and has been patched by some mix cement-lime (gray substance, quite hard-solid) - (see pic 3)

wall 2: non-hollow clinker/breeze blocks. Lime plastered with no extra key (I'm not sure how it sticks to the blocks)

Plan:
I think I can do patch the reed mat and plaster: coarse lime with fiber, then float coat without fiber, and then finishing one
Then it's just to glue the fiberglass wallpaper on top of it and paint.


Questions/suggestions:
1.- The question is for picture 3. Should I apply a NHL float coat to fill the skirting area?, should I use something else? - I kind of like how hard the cement is. But concerned as I think they didn't leave much space for the floor to move.

2.- the clinker blocks wall (I have to apply the scratch, float, and finishing coat). How can I make the lime plaster stick to it?. Would it be enough to clean and apply PVA glue?, any other suggestion (I only see stucco online)?

Am I over-complicating things?, would you guys apply gypsum (given that on top will be fiberglass and there's no humidity issues)?. Given that we'll cover it with fiberglass my main concerns are: for the patches to stick to the previous plaster, the plaster not coming out

sorry for the long message, I can put more pics if you guys are curious (I'm just trying to keep it brief )

 

[malc]

Are Gips black band or Gips gold band base coats available at your builders merchants? These plasters can just be sponged up and trowel finished to receive your wall paper.

 

[Cristian_lime_plaster]

Are Gips black band or Gips gold band base coats available at your builders merchants? These plasters can just be sponged up and trowel finished to receive your wall paper.

Thanks Malc!, I just checked and they are available...

Could you please let me know, in your experience, do you recommend this over the lime plaster because they are easier to use, adhesion?

In particular, I wonder if this would adhere to the clinker blocks (after I clean them and prepare). I read the brochure with the specs and can be build up to 50mm (enough for me), but I'm wondering about adhesion over a block with no key?

 

[Monkey Boy]

Key is key

 

[malc]

Thanks Malc!, I just checked and they are available...

Could you please let me know, in your experience, do you recommend this over the lime plaster because they are easier to use, adhesion?

In particular, I wonder if this would adhere to the clinker blocks (after I clean them and prepare). I read the brochure with the specs and can be build up to 50mm (enough for me), but I'm wondering about adhesion over a block with no key?

Gips is easy to use, you only have to add water . You will be able to dub out to the required thickness. You can 1 coat or 2 coat on the thick areas. Gips has very good adhesion we apply it to the very smooth wallpaper blocks.
It will be cheaper and quicker then lime.

 

[Cristian_lime_plaster]

Thanks!, ok I think I got the main info... I think I'll try Gypsum on the difficult cases to have higher chances of success. But still I'll try plastering the easy places with lime just because I want to learn/test how to use it.

I'll post the results in here in like 1 month or so (need to organise and gather courage) and hopefully could be of help for some others in future. Thanks again malc, I appreciate the help about choosing material