Choice of plaster for renovation of foundation wall, 1945

[spaxx]

Can I repair the holes with any mortar, A or B KC-mortar? Does it need to be red primed before I repair for better adhesion?

 

[leby]

You can probably repair anything, except lime mortar. There should be no need for priming, it should be free from paint and loose plaster. Use fine concrete or abruk. Water before.

 

[Magnus Larsson]

Start watering a few hours before.

 

[spaxx]

It turned out to be tricky to get hold of concrete hollow blocks to replace where broken stones are. Not in stock anywhere in Stockholm, I've seen that you can order but with up to 15 days delivery.

Would it be unwise to use Leca blocks instead?

 

[Magnus Larsson]

I used siporex when I was doing repairs here

 

[leby]

You can use Leca, brick, or set a mold and cast.

 

[spaxx]

You can use Leca, brick or set a form and cast.

Thanks,

Then the same type of rendering mortar should fit both concrete blocks and the chosen repair material similar hardness

 

[leby]

Yes, that's fine.

 

[spaxx]

Hah.. found an interior wall that I believe consists of slag stone, a block was loose and is very heavy.

Alternatively, it could be some sort of massive brick blocks. They are as big as concrete blocks, maybe not as long.

Would regular A/B mortar be sufficient for plastering on such material?

 

[leby]

Difficult to get a grip on hard stone, find a primer, a or b use will work otherwise.