Derbigum Single Layer Torch-Applied Bituminous Overlay When to Specify Derbigum single layer, torch applied, high performance overlay systems offer the highest levels of durability and waterproof integrity when refurbishing existing roofs where the existing waterproofing is reaching the end of its life.
Key Features Lifespan In the Derbigum BBA Certificate 86/1593C, the BBA say ‘All available evidence suggests that the product will have a life in excess of 30 years.’
Durability Derbigum has a high softening point ensuring stability of the membrane in the hottest weather, high tensile strength and excellent puncture resistance. Derbigum can be installed without any surfacing, regardless of the method of application due to the unique blend of polymers which make Derbigum resistant to UV degradation.
Derbigum Cap Sheet (Black or Mineral) Existing Asphalt (primed)
Performance Derbigum is a range of dual-reinforced, APP (Atactic Polypropylene) modified bitumen, high performance roofing and waterproofing membranes with a life expectancy of 30-35 years according to independent assessment. Enhanced performance properties include low temperature flexibility, excellent fire ratings, stronger reinforcement and ease of application.
Existing Sheathing Felt
Cost-effective Derbigum Single Layer Systems combine proven durability with speed and ease of installation and significantly extend the life of the roof without the need for stripping up of the existing roofing, minimising disruption and disposal costs.
Quality
Existing Screed CERTIFICATE No 86/1593
Existing Concrete Deck
Alumasc operates a quality assurance management system which is independently audited to BS EN ISO 9001:2008. Alumasc extends this quality management to their network of approved installers, for single source accountability and peace of mind.
Environment
Warranties Alumasc offers a comprehensive range of warranty options. The typical warranty period for Derbigum is 20 years. Installed exclusively by Derbigum Approved Contractors and underpinned by Alumasc’s extensive project support service, Alumasc warranties cover both product and installation. Independent insurance backed latent product defect warranties are also available through FSA licensed brokers.
ALUMASC EXTERIOR BUILDING PRODUCTS LTD Tel: +44 (0)1744 648400
Email: waterproofing@alumasc-exteriors.co.uk
Website: www.alumascwaterproofing.co.uk Ref: SD005FR Issued: 01/06/12 Page 1 of 2
Alumasc actively pursues sustainability in the full range of products and systems the company offers through its accreditation to the ISO 14001:2004 Environmental Management Standard. Alumasc, its partners and its suppliers are committed to putting consideration for the built and wider environment at the core of all aspects of their current business and future development. Derbigum membranes are 100% recyclable.
Derbigum Single Layer Torch-Applied Bituminous Overlay System Components Application 1. Prepare the existing roofing system to receive the new waterproofing as necessary, including removal of the existing asphalt upstands. Ensure that the roof is clean, dry and free from dust and debris. 2. Prime the existing waterproofing and upstands with Alumasc Bitumen Primer and allow to fully dry. 3. Install Derbigum Black (or Mineral) Cap Sheet, fully bonded by torch application. 4. Note: Pre-cut the lower corner of the end of each roll at 45º where it will be overlapped by the end lap of the next roll.
n Derbigum Black or Mineral Cap Sheet is a high performance, APP modified bituminous membrane, with dual glass/polyester reinforcement, applied by torch. n Hi-Ten Universal is a polyester based underlay, suitable for bonding in hot bitumen (or by torching where appropriate), for use at the details and upstands only. n Alumasc Bitumen Primer is a low viscosity, solvent-based bitumen primer intended to maximise the adhesion of bituminous membranes to metal and porous substrates.
5. Seal side laps (100mm) end laps (150mm) with a shoe burner torch. All laps must be pressure rolled with a 15kg long handled roller. A small (approx 5-10mm) continuous bead of compound must always visible at the joint. 6. All detail work to be executed in two layers, the first layer being Hi-Ten Universal, fully bonded in bitumen, followed by the cap sheet of Derbigum, fully bonded by torching. At all upstands install a 100 x 100mm reinforcement strip of Derbigum Black into the angle. The main sheet area must overlap onto the reinforcing strip by the full 100mm. Install a final flashing piece of Derbigum, fully bonded to the upstand and overlapping onto the main horizontal sheet area by a minimum of 100mm. NB: Derbigum waterproofing systems are exclusively installed by a nationwide network of Derbigum Approved Contractors.
Technical Support Alumasc Technical Services provide an extensive project support service that includes site surveys, project specifications, performance calculations (e.g. U-values, condensation risk analysis), CAD detail drawings and general technical advice. Contact Alumasc Technical Services via: +44 (0) 1744 648400 waterproofing@alumasc-exteriors.co.uk Online resources are available on our website or via the embedded links below: Web Links Brochures & Datasheets NBS Specifications The company pursues a policy of constant product development and information contained in this publication is therefore subject to change without notice. The customer is responsible for ensuring that each product is fit for its intended purpose and that the conditions for use are suitable. All quoted data is nominal and subject to production tolerances.
ALUMASC EXTERIOR BUILDING PRODUCTS LTD Tel: +44 (0)1744 648400
Email: waterproofing@alumasc-exteriors.co.uk
Website: www.alumascwaterproofing.co.uk Ref: SD005FR Issued: 01/06/12 Page 2 of 2
CAD Drawings for typical details www.alumascwaterproofing.co.uk