Dallmer develops innovative drainage systems designed to meet high technical, acoustic, and design requirements in contemporary architecture. This technical guide explains how sound insulation can be effectively integrated into bathroom design, with a particular focus on level-access showers and drainage systems.
The following guide outlines the principles, standards, and practical measures required to achieve effective sound insulation in bathroom drainage systems.
1. Understand the benefits of sound insulation in bathrooms
Sound insulation in bathrooms plays a key role in maintaining long-term building value and protecting the health, comfort, and privacy of residents and users. In residential and mixed-use buildings, poorly insulated sanitary installations are a frequent source of disturbance, especially in vertically stacked bathrooms.
Effective sound insulation reduces noise transmission between rooms and floors, improving acoustic comfort and privacy. In addition to enhancing quality of life, it contributes to the long-term value stability of a building and helps prevent disputes between occupants.
Sound insulation is particularly important in bathrooms, where water flow, impact noise, and footfall sound occur frequently and are difficult to avoid without appropriate technical measures.
2. Define where sound insulation applies and who should be involved in the design process
Sound insulation in drainage technology falls under the discipline of building acoustics and applies to residential buildings, hotels, healthcare facilities, and other buildings with sanitary installations.
Key participants include architects, planners, contractors, manufacturers of building products, owners, and end users. Acoustic performance must be considered early in the planning process, as many sound-related issues cannot be fully corrected once construction is complete.
3. Identify the purpose of sound insulation in level-access showers
In level-access showers, sound insulation has two primary objectives:
- Protection against functional sound (installation noise)
- Protection against footfall sound
Both sound types originate in the shower area and can be transmitted through the building structure if not adequately controlled.
4. Reduce functional sound from drainage installations
Functional sound includes flow noise from water moving through the drainage system and impact noise created when the water jet strikes the shower floor.
The volume of functional sound depends largely on how vibrations are transmitted from the drain body and wastewater pipe into the surrounding building structure. Because contact points between installation technology, drain bodies, and pipework cannot be fully avoided, the primary task of sound insulation is to absorb vibrations and minimise sound transmission.
Installation products, such as the DallFlex sound-proofing pad, separate the drain body from the surrounding screed and significantly dampen functional sound.
| CeraWall Select + DallFlex drain body and DallFlex sound-proofing pad |
 |
| Floor structure
1. Ceramic floor covering
2. Tile adhesive in thin-bed mortar
3. Bonded waterproofing
4. Screed
5. Separating layer
6. Footfall sound / thermal insulation
7. Concrete surface | System design
A. CeraWall Select Shower Channel
B. Sealing sleeve
C. DallFlex drain body
D. Sound-proofing pad
E. Levelling feet |
5. Minimize footfall sound through floor construction
Footfall sound is generated by mechanical excitation of the floor construction, such as walking on tiles or moving objects across the surface. This sound is transmitted to rooms below partly as structure-borne sound through the floor and flanking components, and partly as airborne sound.
As a result, the entire floor structure must meet requirements for both airborne and footfall sound insulation. Floor constructions using floating screed with sufficient mass and resilient, sound-absorbing layers have proven particularly effective.
High-quality footfall sound insulation, typically made of mineral wool or EPS insulation, can reduce footfall noise to a level that is barely perceptible or no longer audible in the rooms below.
6. Apply relevant sound insulation standards and guidelines
Two regulations are particularly relevant as references for sound insulation in bathrooms:
- DIN 4109, which specifies the minimum requirements for sound insulation
- VDI Guideline 4100, which defines increased sound insulation requirements aimed at improving acoustic comfort and privacy
Always review the local regulations so the project complies with the required standards.
7. Check permissible sound level limits
For functional sound, the decisive value is the installation noise level LAFmax,n (or LAFeq,n). Under increased sound insulation requirements, installation noise must not exceed 30 dB or 25 dB, depending on the performance level.
For footfall sound, the key value is the standardised footfall sound level L’n,w. DIN 4109 specifies a maximum permissible value of 53 dB, while increased requirements reduce this limit to 46 dB for ceilings below bathrooms and toilets in multi-dwelling buildings.
8. Integrate sound insulation measures into system design
Effective sound insulation in level-access showers depends on the interaction between drainage systems, installation components, and floor structure.
Tested system solutions that combine shower channels, drain bodies, and sound-proofing pads can meet or exceed the requirements of DIN 4109 and VDI 4100 when installed in accordance with approved test reports.
By separating the drain body from the surrounding screed and integrating suitable footfall sound insulation into the floor build-up, both functional sound and footfall sound can be significantly reduced.
Explore Dallmer’s product catalog or visit their website to learn more about drainage solutions with tested acoustic performance for bathroom applications. Download the PDF for additional information.
