ᐅ Railing-supported staircase on screed or unfinished subfloor?

Hello everyone,

Do load-bearing stair railings need to be anchored to the rough subfloor, or can they also rest on the screed? I have two quotes for such staircases, and both stairbuilders want to have the stairs rest on the screed because the compressive load is not very high.

One stairbuilder writes that the newel post rests on the screed and is fixed with a dowel. The dowel could also be extended down to the rough subfloor.

The other stairbuilder writes that the newel post also rests on the screed and that a rubber bearing is placed between the screed and the newel post.

The staircase is supposed to run from the basement level up to the ground floor without a stringer attached to the wall. What I have mostly read so far is that stairs must be installed on the rough subfloor and that fixed components must not be connected to a floating screed. But why do the stairbuilders propose having the newel post rest on the screed? What are your thoughts on this, or is there any applicable standard, such as a DIN, regarding this? Many thanks.

My feeling is that a raw subfloor is better. By the way, this is also how it was done in our case. At the start and end points, the screed was left out accordingly to avoid drilling or hammering.

Uwe82 schrieb:
My feeling is that a raw subfloor is better.

I agree, and the effort required is probably quite limited. What surprises me, however, is that stair builders don’t usually plan for this. Unless the point load on a railing-supporting staircase isn’t very high. And if the newel post only rests on a rubber pad, the screed can still accommodate some movement.