FAQ – frequently asked questions

Here you will find answers to some of the questions we often receive. If you would like more comprehensive information, we recommend reading our whitepaper / technical documentation here.

This short video shows in plain language how the ProSilence system disconnects and removes unwanted vibration noise. Remember that all sound is moving waves, in this case transferred to water to visualize the effect!

Can I soundproof on top of existing walls, ceilings and floors?

– No , you get a so-called “triple leaf effect” as a result of three surfaces. One surface is, for example, the floor on the floor above and the ceiling on the floor below. You should only have two surfaces in an optimal soundproofing solution, so you should remove existing layers of boards as far as possible for the best possible effect. However, if the existing floor is compact enough and lies against concrete, it can function as one “layer” and thus in some cases U-boats can be laid directly on the existing floor. In floor partitions based on wooden joists, it is generally recommended to remove the floor so that you can get underneath and secure only two layers, but the load-bearing and bracing function of the floorboard must also be taken into account, which depends on things like the dimension of the joists and the size of the floor. To reduce the effect of triple leaf in cases where the floor sheet is not removed, it is recommended to perforate the substrate with holes. Up to 20% holes will reduce the triple leaf effect considerably, but will at the same time reduce the load-bearing capacity/rigidity too much, so 10-15% is often what you should choose. In all cases where load-bearing floors are involved, it is recommended to have the project assessed by a technical professional, please read our white paper for more information.

Do I lose a lot of headroom when using the ProSilence system?

– ProSilence is designed to minimize loss of ceiling height, where you can use so-called “cubbing” in the ceiling and thus avoid loss of height beyond around 5mm clearance and possibly 12.5mm for extra (fiberglass) plate layer if you use two layers. If clips are installed in a concrete ceiling, you will lose around 35mm ceiling height + battens of e.g. 25mm. Alternatively, clips can be attached directly to the concrete ceiling to avoid the use of battens, but this involves a relatively large amount of work as each clip uses three attachment points. We also have some brand new brackets available as an alternative to cubbing. You can also build our U-boats into the floor if you have wooden floor partitions and thus almost avoid loss of height, but even if you build the U-boats directly on the existing substrate, this will only result in a 48mm loss of height (in addition to 12.5mm for any extra layer of fiberglass). Keep in mind, however, that in load-bearing floors, the effect of removing the floor sheet metal as a stiffening surface must always be assessed by a professional. Read our white paper for more detailed information.

Is it sufficient to add an extra layer of fiberglass plaster for sound insulation?

– No , adding an extra layer of fiber plaster alone is rarely sufficient. While this may provide some improvement in sound insulation, it will not solve the problem of structural sound or sound leakage through existing structures. For more effective sound insulation, we recommend using decoupling through our ProSilence Clips and U-Boats, which significantly reduce sound transmission.

Can I use regular plaster instead of fiber plaster?

– On the first layer, fiber plaster must always be used as it is screw-tight and the next layer must be installed in the plaster and not in the ProSilence steel studs. The second layer can be replaced with ordinary plaster, but be aware that you will lose 25% of the effect as one layer of fiber plaster has double the insulation effect compared to standard plaster.

What are ProSilence Clips and how do they work?

– ProSilence Clips are specially designed sound-absorbing fixing clips that decouple wall or ceiling structures from the existing frame. This reduces sound transmission between rooms, especially low-frequency sounds. The clips are used together with steel rails and plasterboard.

What are ProSilence U-Boats and why should I use them?

– ProSilence U-Boats are vibration-damping pads that are placed under floor joists or floating floors to reduce structure-borne sound (sound traveling through solid materials such as floors and walls). They ensure that the floor is decoupled from the rest of the structure, providing significantly better sound insulation.

What measure levels do you recommend for sound insulation?

We have three recommended levels of action, as explained here:

– Minimum measures:

Decoupling with ProSilence Clips and/or U-Boats for walls, ceilings and floors. A single layer of fiber plaster is used here.

Moderate measures:

Same as above, but an extra layer of fiber plaster with GreenGlue damping adhesive between the panels. In addition, a sound door is used.

Maximum measure:

Two layers of fiberglass plaster also on the other side of the wall, our strongest acoustic door and separate, soundproof ventilation.

What is the difference between airborne noise and structure-borne sound?

– Airborne noise is sound that travels through air, such as speech, music or the sound of a TV. Structure-borne sound is sound traveling through solid materials, such as footsteps, knocking or vibrations from machinery. Effective sound insulation requires measures that address both types.

How much sound insulation can I expect when using your systems?

– The result depends on the action level and existing construction, but our solutions can significantly reduce both airborne and structure-borne noise. By using ProSilence Clips, U-Boats and fiber gypsum, a noticeable improvement can be achieved.

How do I know which measures I need?

– If you’re unsure, we can help you find the right solution based on your needs and budget through our engineering service here. Our recommendations range from simple improvements to advanced soundproofing systems. For larger projects or uncertain situations, we can also perform a professional sound measurement both before and after.

Can I install your systems myself?

– Yes, our solutions like ProSilence Clips and U-Boats are designed to be easy to install for both professionals and hobbyists. We offer tutorials and support if you need help along the way.

Why is low-frequency sound harder to isolate?

– Low-frequency sound (e.g. deep bass sounds) has longer wavelengths and penetrates building materials more easily. Isolating these frequencies often requires more extensive measures, such as decoupling and the use of heavier materials.

Do I always have to use both ProSilence Clips and U-Boats?

– Not necessarily. It depends on where the sound is transmitted and what your biggest problem is. ProSilence Clips are used on walls and ceilings, while U-Boats are used for floors. In many cases, it is recommended to combine both for optimal sound insulation.

Do I need to use GreenGlue between the board layers?

– GreenGlue is a sticky mass that never hardens. The mass works by setting it in motion and extracting sound energy in the form of heat. The effect is very good and the wall appears far more dead and effective, so using GreenGlue between board layers is our clear recommendation after many years of experience using this damping adhesive. By the way, GreenGlue is not an adhesive, even though the name suggests this. Remember that there is a difference between GreenGlue Compound, which is the compound you place between the board layers, and GreenGlue Sealant, which is used in the board joints (flexible and stable sealant).

Do I need to think about ventilation?

– If you are soundproofing an entire room rather than just a single wall or equivalent, ventilation is an absolute requirement, as the room is hermetically sealed to maintain its function. If you’re going to use an existing ventilation solution, it’s therefore important that you have both supply and extract air in the soundproofed room. In many cases, and especially in rooms where several people will be staying, such as a home theater or media room, the common system delivers too low air exchange, and thus our DreamScreen CineVent solutions are often recommended, which is a separate unit that is only used in the soundproof room. This ensures sufficient air exchange. Also remember that the vents must be soundproofed, and the solutions often specified by ventilation companies are in many cases too weak. In short, use at least 1 180-degree bend with at least 1 meter before and after the bend towards each inlet and outlet, well insulated with at least 10cm insulation around the entire pipe. The type of pipe can be Flexit’s flexible sound trap pipes. When you purchase project planning from us, we will deliver proposals for the installation of soundproof ventilation.

Why do we use silica gel instead of rubber in our decouplers?

– We’ve always been on the lookout for the perfect material for decoupling! We’ve been testing and using rubber for many years, as well as testing a number of other solutions, such as synthetic TPE plastic. The main challenge with all rubber is that, over time, it becomes hard and stiff and thus loses its decoupling effect. Synthetic TPE does not have sufficiently good fire-retardant properties. That’s why our clips and U-boats are designed in our proprietary composition of silica gel, which is adapted so that it decouples very well and at the same time has sufficient load-bearing capacity. Silica gel will never become as hard as rubber and our specially developed material is also unique in terms of fire resistance.