There are various types of stairs, making it possible to get from one floor to another. In this first part, the Acousticshop worked out a solution to acoustically decouple a spiral staircase from a storey floor in cooperation with Van Cleef Conceptual Design.

Sound Insulation for Stairs | Part 1: Vibration Insulation for a Spiral Staircase

Insulating contact noise

In case of a spiral staircase, there is only one type of sound problem: namely contact noise. The spiral that connects the steps transmits the vibration produced by walking to the floor on which it stands and the storey floor to which the stairs lead. Contact noise from a stairs can only be insulated when the stairs is placed well, after installation nothing can be changed!

Decoupled placing of the spiral stairs

In order to place the spiral stairs on vibration insulation in both an acoustically sustainable and safe manner you will need some technical insight. There is a lot of weight involved and your safety is at stake. The following instructions are devised by a customer and we think they are solid as well! 

In order to steadily position (yet decoupled from the floor) the point load from a heavy stairs including its users, a steel H beam is equipped at its bottom with Regufoam D300 with a thickness of 25 mm.


Then, the H beam is filled with four wooden beams, which will be equipped with Regufoam D300 with a thickness of 12 mm later on. This construction forms the load-bearing foundation of the spiral stairs.

On the pictures below, you can see how the load-bearing foundation all around and embedded in a wooden construction. This massive wooden construction will later on form a platform that is part of the stairs' design. The platform will be sturdily anchored to the concrete floor and fulfills a double function: first of all to keep the stairs in its position, and secondly, in order to hide the decoupled steel H beam from sight. Inbetween the stairs and the steel beam, a hardwooden beam is beamed is mounted to provide a nice finishing. The rest of the round platform will match this hardwooden beam with the same type of wood. After installing the cast-iron staircase, the Regufoam indented 2 mm. This amount will depend per situation.


Steel H beam Regufoam D300 embedded in wooden frame

The end result
The end result looks beautiful! A nice attic in a monumental building that contains a wooden floor, without the problem of contact noise!


Do you have any questions or comments concerning this topic or do you wish to receive a product sample? Feel free to contact us!

Do you want to know more about insulating wooden (storey) floors? Click here.