Eden Boys' School Case Study

Eden Boys’ School in Preston is part of the Star Academy Group. The school was experiencing water ingress and damage causing staining the internal decorations. Bauder was instructed by AHR, Manchester to assist in qualifying the issues and make recommendations for repair or replacement. Following a detailed survey and some of the deepest trial holes undertaken to date, the report concluded that the original waterproofing system had significantly surpassed the design life as three subsequent overlays had been installed to a very poor standard. The only viable option was to strip various layers of contaminated build-up and install a new robust waterproofing solution, alongside improved drainage details and revised detailing to the various interfaces.

 

Bauder Building Board

 

Project:	Eden Boys’ School
Location:	Lancashire
Project type:	Refurbishment
Roof area:	1567m2
Specifier:	AHR Building Consultancy Ltd
Approved contractor:	FRS Roofing Services Ltd

The saturated condition of the original various waterproofing systems had severely impacted the thermal performance of the school. For that reason, the removal of these various existing waterproofing systems presented the opportunity to thermally upgrade the building to comply with current building regulations.

The systems installed

The Bauder Total Roof System (BTRS) in Charcoal Grey was installed by FRS Roofing Services Ltd at Eden Boys’ School.



This system contains some of the most advanced bitumen membranes available and benefits from Bauders own high-performance insulation. The Bauder K5K membrane in this system are manufactured using highly modified SBS elastomeric bitumen which offers maximum flexibility and high tensile reinforcing layers, meaning this advanced waterproofing system can withstand climatic extremes and resists impact and tearing.

BauderPIR FA-TE Flatboard Insulation is an extremely efficient PIR insulation board with aluminium foil facing on both sides. The top facing features a printed grid pattern to aid site cutting. It is lightweight and has zero ozone depletion potential.

Challenges and considerations

Initially several water blisters had been observed to the gutter details, indicating significant failure of sections from the existing system. The condition survey summarised that the existing roof had been overlaid several times using differing liquid and bituminous options in addition to a mix of bonded and mechanical fixings. As water had been tracking back and forth between the various layers and down through the build-up of all the overlays, the existing system had to be removed and replaced.
The new Bauder waterproofing system would include insulation in compliance with current Building Regulations. A minimum average of 0.18 W/m2K had to be achieved, not a single point on the roof could exceed 0.35 W/m2K. Upgrading the insulation helped the building comply with current Energy Conservation Regulations as well as benefit from long-term energy savings.

Due to the nature of the building, it was important to consider strong and durable waterproofing to minimise the risk of physical damage to the building and its occupants. FRS Roofing Services Ltd were faced with the challenge of removing the circa 300mm of build-up, whilst ensuring that the school remained weather tight. This was achieved and expertly undertaken.

During the installation, the existing cladding was removed to allow working access in order to raise and waterproof the abutment upstands, all in line with Bauder guidelines. This ensures that the roof maintains integrity and the British Standards are met.

At the time of the survey, it was recognised that using torch-on materials would not conform to the recommendations of BS 8217:2005. This states when facing an area which contains combustible material, a minimum 900mm deep zone of the flat area around the material (and any detail flashing to the material itself) requires 'Torch-Free' detailing. The use of gas torches was not appropriate for the application of the roofing membranes, meaning that this project utilised a Torch Free Plan to ensure a safe installation and mitigate any fire risk. This was especially important as the building was often occupied when roofing work was being carried out.

The H5 Acoustic Performance outlines that educational buildings have acoustically sensitive rooms. Therefore, during the early stages of planning for the roof refurbishment, a calculation for rain noise was taken to measure the impact made from the noise of rain falling onto the roof. According to the BB93, The Department for Education and Skills design guide, which explains how building regulations should be designed to provide suitable control of rain noise reverberant sound pressure level in space, during heavy rains noise levels should not be more than 25dB above the appropriate indoor noise. If this is not considered, the indoor noise level could be significantly impacted from the rain which could result in disturbances inside the school.

Why Bauder

A detailed condition survey and an accurate bespoke project specification was provided to the client from Bauder which facilitated a fully informed decision and obtained accurate tender returns. Along with the fully complaint Bauder insulation and waterproofing system, a team of Bauder site technicians monitored and provided support during the installation by FRS. This full service offers the client reassurance of longevity and the assurance that the project would benefit from the Bauder guarantee.

Choosing a Bauder system warrants the complete system compatibility and single source responsibility. All of the Bauder product systems are tested by the British Board of Agrément ensuring that these systems and products meet the latest criteria and current regulations.