Meridian High School Case Study

Meridian High School is a coeducational secondary school with academy status, located in the New Addington area of the London Borough of Croydon.

Bauder Building Board

Project:	Meridian High School
Location:	Croydon
Project type:	Refurbishment
Roof size:	2046m²
Specifier:	Daniel Connal Partnership
Building owner:	GLF Schools
Approved contractor:	Skyler Contracting Limited

The Survey

Bauder area technical manager, Chris Clarke, carried out a condition report on the flat roof areas that were causing concern. Core samples were taken from various locations of the roof. They identified that areas of the deck were damp, confirming that the waterproofing was failing there. A visual appraisal showed that several of the roof areas had substantial greenery growing on them and detritus that was, in some instances, blocking the guttering. The roof surface was showing typical signs of ageing such as surface oxidisation, cracks, splits, blisters, rucks, and laps coming apart.

The thermal performance of the existing roof build-up was poor and well below current standards. One of the risks associated with inadequate levels of insulation is the potential for condensation to form within the structure or waterproofing system during periods of climatic extreme. The insulation on this project would need to be upgraded to meet current Building Regulation requirements.

The survey confirmed that the existing waterproofing on much of the building had come to the end of its service life and needed refurbishment before a serious failure occurred. The proposal for renovation included upgrading the insulation, replacing the rooflights and increasing the upstand height around the glazing.  
 

Systems installed

Bauder approved contractors, Skyler Contracting Ltd, installed the following systems and products at Meridian High School.

Bauder Total Roof System PLUS
The Bauder Total Roof System PLUS (BTRS PLUS) features the most advanced bitumen membrane currently available, BauderKARAT. The dual modified cap sheet utilises APP modified bitumen for robust weathering durability and a bottom layer of SBS modified bitumen for maximum flexibility. The composite glass-polyester reinforcement sits between the two layers. BTRS PLUS is suitable for use on both refurbishment projects and new constructions.

BauderPIR FA-TE Insulation
The installed system incorporated BauderPIR FA-TE Insulation in a variety of thicknesses to achieve the required U-value for the school. This aluminium faced insulation is extremely efficient and lightweight – ideal for refurbishing an existing roof where weight loadings may be a consideration. Bauder insulation provides excellent thermal performance and has outstanding dimensional stability and compressive strength, achieving an “A” rating in the BRE Green Guide.

Rooflights
Natural light is provided by a large continuous structural rooflight, mounted upon an upstand kerb. The glazing is thermally inefficient, and in some places cracked, allowing water ingress. The old glazing was replaced with Bauder Structural Rooflights, a modern thermally efficient structural rooflight, and kerbs were raised where necessary to create a minimum upstand of 150mm.
The BTRS PLUS system offers the highest levels of performance supported by the most comprehensive guarantee on the market.

Systems and products

Bauder Total Roof System PLUS with BauderPIR FA-TE Insulation
   

1 BauderKARAT cap sheet	5.2mm thick dual modified APP/SBS, torch applied bitumen cap sheet offering the ultimate waterproofing solution.
2 BauderTEC KSA DUO 35 Underlayer	A self-adhesive elastomeric bitumen underlayer.
3 PIR FA-TE insulation	BauderPIR FA-TE Insulation was used on this project to upgrade the thermal performance of the building to meet current standards. Various thicknesses were used on the different roof areas.
4 VB4-EXPAL	This robust bitumen AVCL provides temporary waterproofing once laid, ideal for refurbishing a dilapidated roof.

 
Structural Rooflight

There are a number of Bauder Structural Rooflights that can be utilised to fulfil the requirements of a roof refurbishment or enhance the design of a new build project.

• Mono-pitched
• Pitched polygon
• Self-supporting pyramid
• Ridge light
• Hipped-end
• Low-profiled barrel vault