Alumasc Roofing

Caltech QC

Manufacturer: Alumasc Roofing 

Materials: Poly Methyl Methacrylates (PMMA) 

Caltech QC is based on a two-component, liquid-applied polymethylmethacrylate membrane, reinforced with an embedded polyester fleece with a nominal mass per unit area of 110 g∙m2

The system is available in winter and summer grades, for use where application temperatures are between 0°C and 20°C, and 10°C and 35°C respectively.

The system is applied to provide a waterproofing membrane with a minimum dry film thickness of 1.8 mm

BBA logo

Number: 17/5392 PS1
Issue date: 02/03/2017

Approved for use on

Flat Roofs Green Roofs Pitched Roofs Roof Gardens 

For use as a fully adhered waterproofing layer on new and existing:

  • exposed flat and pitched roofs with limited access
  • protected (including zero pitch) and inverted roofs with limited access
  • green roofs and roof gardens


Concrete Mastic Asphalt Steel 

The system has been assessed for use on concrete primed with Caltech QC Primer C, asphalt primed with Caltech QC Primer B, and unprimed steel. The adhesion to and compatibility with other substrates must be confirmed by test


25 Years 

Accelerated weathering tests and evidence from existing installations confirm that satisfactory retention of physical properties is achieved. All available evidence indicates that, under normal conditions, the system will have a service life in excess of 25 years.

Installation Requirements

The system should only be installed by installers who have been trained and approved by the Certificate holder.

Puncture Resistance

P1 - non accessible

Most Compressible Substrate (eg insulation)

P4 - roof gardens, inverted roofs and green roofs)

Most Compressible Substrate (eg insulation)

Fire Safety

A composite build-up comprising: • Caltech QC (pebble grey) applied at a rate of 3.1 kg∙m–2, including Caltech QC RF110 Reinforcement • a 0.6 mm thick bitumen carrier membrane • 120 mm thick PIR Insulation board bonded to a vapour control membrane with a two-component PUR adhesive • 19 mm thick plywood primed with a synthetic rubber resin, when tested in accordance with DD CEN/TS 1187 : 2012 (test 4) was classified in accordance with EN 13501-5 : 2005 as European Class BROOF(t4), and when tested in the flat position in accordance with BS 476-3 : 2004 achieved an EXT.F.AA rating. The system can contribute to a roof being unrestricted under the national Building Regulations.

Protected or inverted roof specifications, including an inorganic covering listed in the Annex of Commission Decision 2000/553/EC, can be considered to be unrestricted under the national Requirements

The designation of other specifications should be confirmed by: England and Wales — test or assessment in accordance with Approved Document B (Volumes 1 and 2), Appendix A, clause A1 Scotland — test to conform to Mandatory Standard 2.8, clause 2.8.1 Northern Ireland — test or assessment by a UKAS accredited laboratory, or an independent consultant with appropriate experience.

In the opinion of the BBA, irrigated green roofs and roof gardens will be unrestricted under the national Requirements.

If allowed to dry, plants used may allow the spread of flame across the roof. This must be taken into consideration when selecting suitable plants for the roof. Appropriate planting, irrigation and/or protection must be applied to ensure the overall fire-rating of the roof is not compromised.

Certified Products

The following products are also covered by the same certification:

  • Downloads

Alumasc Roofing

White House Works
Bold Road
St Helens

T : 01744 648 400

E :

Website disclaimer:

“The information contained in this Website is for general information purposes only. The information is provided by manufacturer members and their accreditation certifications and while we endeavour to keep the information up to date and correct, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with regard to information or products. Any reliance you place on such information is therefore strictly at your own risk.

LRWA Is not an accreditation body and does not test products or have a role in determining whether a product or system is fit for purpose. An agrément certificate is only issued for a successful product or system following a detailed assessment including both laboratory testing and inspections by the certificate provider.”