Order screed - plaster

@: "xray107"
I do not know to whom you directed your additional inquiry, unfortunately without a greeting.
"What advantages do you see in the order screed/plaster compared to plaster/screed"
No one wrote here about advantages or disadvantages.
It is usual (and also the easiest way) to work the screed onto the existing wall plaster.
However, Christian also asked:
"Now you keep reading that the plaster must be pulled down to the floor slab for airtightness... is that really so?"
This question has remained unanswered so far.
The answer to this is: NO.
Wall plasters have nothing to do with airtightness in any case.
The reason to work a screed over edge strips onto wall plaster (not the other way around) is only that it is easier to handle the sound insulation or the edge strip this way.
And that wall plasters would be pulled down to the floor slab is wrong!
The edge strip (which you, Christian 123, probably confused with plaster) must, according to DIN 18560, rest down on the floor slab or else (with larger layer thicknesses) on the lower insulation layer, which normally forms thermal insulation on ground floors.
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In the hope that no further questions remain open here: KlaRa

I asked my greeting-less question to the thread starter.

""Now you keep reading that the plaster must be applied down to the base slab for airtightness reasons... is that really the case?"
This question has remained unanswered so far.
Answer to this: NO.
Wall plasters have nothing to do with airtightness in any case"

Maybe I completely misunderstand your post, but everywhere you read that the interior plaster must be applied down to the base slab.
Connection wall - floor:
Especially the exterior walls must be plastered tightly to the base slab, otherwise unpleasant cold air pockets in the foot area may occur later. Therefore, there must be no gap anywhere between screed and plaster.


btw: I also miss a "Hello" and a "Best regards" in your post to me. *puzzled*

Hello,

...and thanks for the previous answers.


On the one hand, I thought it was quite nonsense to build the walls with highly insulating bricks, insulate the roof and the floor slab thickly, and then apply plaster everywhere up to, or just above, the floor slab... In my opinion, this consistently represents a thermal bridge, since the plaster of course does not come close to the WLG023 of the PUR insulation. On the other hand, I would like to have a continuous insulation layer directly on the floor slab, on which the pipes are then laid and thus already "warm." Of course, that is not possible if I have the plaster applied first.

: Thanks!

Best regards,
Christian

With airtightness, wall plasters have nothing to do in any case.

I am surprised by this answer from an expert... of course, the interior plaster forms the airtightness layer – where else should it come from? That is why the plaster is always extended down to the floor.

And a thermal bridge? You can also exaggerate – after all, a floor slab or ceiling is insulated on the sides as well, so how should there be a thermal bridge because of the plaster or the insulation not fitting perfectly?

Hi Sebastian79,

side insulation: yes, but there is no insulation under the floor slab at all... Pulling it onto the floor slab is also relative, as the plasterer goes at most up to the folded vapor barrier, if I have understood correctly. Because the plaster would not adhere to that.

Regards
Christian

I didn’t talk about under the slab either, but at - meaning sideways, because there definitely belongs perimeter insulation there.

The plaster sticks there already - it’s not a foil (or do you actually have one there?). Are you perhaps confusing that with up on the roof?