McGarrell Reilly Homes - REGUPOL vibration 450 - Foundation Isolation

When developing two three-storey apartment blocks adjacent to an active railway boundary in Cambridge, McGarrell Reilly Homes required a foundation isolation strategy capable of mitigating ground-borne vibration and preventing Structure-borne noise transfer into residential dwellings.

Working alongside the structural engineers and main contractor Durman Stearn, CMS Danskin Acoustics specified a combined REGUPOL RAV 300 (now vibration 450) and our vertical isolation foam system to isolate both the base and perimeter of the concrete foundations, ensuring long-term vibration performance and structural protection.

This approach allowed the development to proceed with confidence despitechallenging ground conditions and proximity to active rail infrastructure.

THE CHALLENGE

The site was located directly adjacent to a live railway boundary, creating a significant risk of ground-borne vibration entering the building structure.

Primary risks included:

• Transmission of low-frequency vibration into

residential units

• Potential Structure-borne noise affecting occupant

comfort

• Long-term structural fatigue caused by repeated

vibration loading

• Requirement to integrate mitigation measures at

foundation stage

A solution was needed that could:

• Deliver vibration isolation at low frequency
• Maintain structural load capacity
• Adapt to variable ground conditions
• Integrate seamlessly within the construction programme

THE SOLUTION

CMS Danskin Acoustics specified a dual-material isolation strategy to achieve complete foundation isolation.

Base Isolation - 185m² of 50mm REGUPOL RAV 300 (now vibration 450)*

Installed beneath the concrete foundation slab

Polyurethane-bound recycled rubber granulate material

Designed to achieve natural frequencies in the range of 8– 12Hz

Perimeter Isolation - 560m² CMS our vertical isolation foam system

Installed to the vertical sides of the foundation pits

Medium-density closed cell structure foam

Natural frequency performance in the range of 10–12Hz

Due to the rough excavation faces, permanent formwork was introduced to create a consistent substrate for installation. Once isolation materials were in place, a damp proof membrane was applied and the concrete footing cast as normal.

This ensured full encapsulation of the foundation structure within a vibration isolation envelope.

THE RESULT

Following preparation of the foundation pits and installation of

permanent formwork, both REGUPOL RAV 300 (now vibration

450) and our our vertical isolation foam system were installed

efficiently and without programme delay.

Garry Ford, Company Buyer at Durman Stearn, commented:

“The flexibility of REGUPOL RAV 300 meant we could easily

overcome the unexpected complications of the ground

composition. Once the sides of the foundation pit had been

prepared with formwork, the installation of the anti-vibration treatments was straightforward.”

The adaptability and proven performance of the isolation

system provided confidence to both contractor and developer,

leading to continued specification.

TECHNICAL EXCELLENCE.

EXCLUSIVELY DELIEVERED.