Soundproofing a shared wall between two flats

Published on 05 Dec 2024

Left: PhoneStar installation Right: Complete project with PhoneStar hidden inside the wall. 

Property owner Chris set out to transform a single dwelling into two self-contained flats, with the main challenge ensuring privacy between the two spaces. The primary concern was sound transfer through the locked door dividing the units. 

PhoneStar, an acoustic board was installed over the shared door to minimise sound transfer. 

PhoneStar contains structured cardboard layers filled with sand that are specifically designed to reduce sound transfer and dampen low-frequency noises—key factors for maintaining privacy in partitioned living spaces.

The PhoneStar boards slot into aluminium channelling, with the structure supported against polystyrene that had been shaped and fitted against the locked door. This setup provides an extra layer of insulation, reinforcing the sound barrier.

Since PhoneStar was only applied to the most problematic area, rather than the entire shared wall, some sound transfer remained. However, the reduction was significant, creating a much quieter and more private environment for future tenants

Chris was pleased with the results, as even a small area of PhoneStar proved highly effective in addressing the noise challenge, helping to achieve the self-contained living experience he had envisioned.