Cyril le Marquand House in St Helier, Jersey is home to the offices of States of Jersey. The first floor terrace area had been waterproofed with a GRP warm roof system that was now in an aged condition. Due to the unsuitability of the old roofing system to withstand foot traffic, the wear and tear of every day use had led to various punctures and mechanical damage. As a result, water ingress was occuring into the interior of the building and the insulation was deteriorating.

The client turned to Polyroof for a solution that would provide a system that could offer the highest performance across three key criterium: thermal insulation, waterproofing durability and foot traffic resistance. Following a survey by Polyroof Technical Services it was found that the existing roof was in such a poor condition that it would need to be completely stripped back to the original asphalt membrane. Furthermore, numerous details and upstands were present that restricted the potential height of the new roofing system - meaning a traditional trafficked warm roof with insualtion and a plywood or OSB deck, would present difficulties.

ad been suffering from leaks for a long period of time, which had to led to water ingress. As a result of this the existing insulation was becoming defective, leading to growing fuel bills. The client turned to Building Renovations Ltd, a Polyroof approved contractor, for a solution.

There were a number of design constraints that made efficiently improving the thermal performance using traditional balcony systems difficult; the addition of a plywood carrier layer would have impacted on the thickness of insulation that could be installed. A durable waterproofing membrane with a tough anti-slip finish was also required to ensure long-lasting protection from leaking.

Polyroof ‘RES’ Balcony Insulation provided the ideal solution for this thermal upgrade application. The system consists of high performance T&G rigid polyisocyanurate (PIR) foam insulation with a 3mm high-strength, non-compressible and puncture-resistant facing board which provides total protection from regular balcony usage.

After considering the client's requirements for the refurbishment, the Protec Balcony Warm Roof System was put forward as a complete solution. The system includes the innvoate Polyroof RES Balcony Insulation: a high performance T&G PIR board with a 3mm high-strength, non-compressible and puncture-resistant facing which provides total protection from regular balcony usage.

Following the removal of the old insualtion and GRP membrane, the asphalt membrane was made good so that it could provide a vapour control layer. Polyroof RES Balcony Insulation was then bonded to the asphalt - without the need for any mechanical fixings. The Protec waterproofing system was then directly applied to the insulation boards and finished with the Quartz Sand & Polyfinish for an extra-durable, hard wearing surface.

The client had peace of mind that the terrace could be used for heavy traffic without the risk of damage to the roofing system and, with Polyroof's trusted 20 year insurance backed guarantee, their terrace could not be better protected.