35 bauder. co. uk Equipment The equipment used for hot air welding is very specialised and we recommend only two manufacturers: 1. Leister Side laps – one of the following:- n Leister Varimat or Bitumat automatic hot air welder 240V/ 4600W with an 80 mm nozzle. n Leister Electron hot air hand tool 240V/ 4500W with an 80 mm nozzle. Head laps and all detailing n Leister Electron hot air hand tool 240V/ 4500W with an 80 mm nozzle. 2. Sievert Side laps – one of the following:- n Sievert TW5000 automatic hot air welder 240V/ 5000W with an 80 mm nozzle. n Sievert TH1750 hot air hand tool 240V/ 2300W with an 80 mm nozzle. Head laps and all detailing n Sievert TH1750 hot air hand tool 240V/ 2300W with an 80 mm nozzle. Both machines are available for hire or purchase throughout the UK via authorised distributors. Ancillary Equipment Other necessary equipment: 1. A current distribution box with a 64A feed to 3 No. sockets ( 20A per socket), each with separate ON/ OFF switch and residual current circuit breakers. 2. 4 mm ² safety extension cables. These are available from Leister and Sievert stockists. Electrical Requirements It can be seen from the above information that a 240 Volt supply will be required to use this equipment. This can either be taken directly from a connection to the building's mains power supply, or from a suitable generator. Unfortunately equipment running on 110 Volt is not powerful enough to provide the heat required to adequately bond bituminous membranes. Generator Specification In situations where it is not possible or practical to use the mains supply, it will be necessary to use a generator with a 10KVA output. n Allows the operative to aim the flame of the torch directly at the roll, therefore avoiding direct contact with the deck or insulation, which could lead to unnecessary product damage or a fire risk. n The weight of the roll bar helps to evenly spread the bitumen flow across the roll. The operative can clearly see the bitumen flow and adjust and control the application speed to suit. n When laying the membranes, the operative can control the speed and bitumen flow accurately, to achieve a neat, even, bitumen bead extrusion from all the lap joints. This is especially important when applying mineral surfaced capping sheets. n The operative can avoid leaving unsightly foot marks in the newly laid ( and still hot) material by walking in front of, rather than walking directly on the membrane being applied. Bauder Long Handled Laproller This product was developed by Bauder specifically for the lap sealing of the ' DUO' range of products, in order to make this operation as quick and easy as possible. SELF ADHESIVE MEMBRANES The Bauder self- adhesive products feature a peel- off foil, which protects the self- adhesive bitumen compound from ultraviolet radiation and prevents the product sticking to itself inside the roll. These products are simply laid into position and rolled up with the roll bar spindle inside. The peel- off foil is removed allowing the membrane to be adhered to the prepared substrate or previous layer. The self- adhesive properties of the bitumen compound are severely reduced when the ambient temperature is below 5° C. This is not a problem when installing BTRS DUO as the self- adhesive vapour barrier and underlayer used within this system both receive heat on their top surface after they are laid, which subsequently activates the underside. However, System Airtech does not receive the same amount of heat and for this reason should not be installed in the winter months. HOT AIR WELDING Overview In instances where naked flames are not permitted on site, but a Reinforced Bitumen Membrane System is still the preferred option, the membranes can be welded together using hot air. Pure self- adhesive is not considered adequate at lap joints as this does not create a homogenous bond between the layers, which is critical to waterproofing integrity. Bauder System Airtech utilises self- adhesive membranes with hot air welding of ' DUO' laps and Bauder Insulation adhesive, to create a RBM solution without flame or hot bitumen. TECHNICAL GUIDE

36 bauder. ie INSULATION APPLICATION METHODS There are 3 methods of bonding insulation that can be used depending on the system specified: Hot bitumen This is the most traditional and still the most common way to bond insulation in bituminous warm roof systems. Grade 95/ 25 bitumen should be used at a temperature of 220- 230° C, poured onto the vapour barrier from a watering can. This is the standard product used in BTRS and Bauderflex systems as it provides a thick, self levelling bed to which the insulation can be applied, with time to move the boards into position before a strong bond is achieved. This product requires the use of a heating pot and therefore a degree of risk to Health and Safety. It is therefore slowly being replaced by alternative products and methods of installation. Bauder Insulation Adhesive This is a foaming polyurethane adhesive, which is poured onto the vapour barrier directly from the tin. It is applied in 8- 10 mm wide continuous strips approximately 200 mm apart, so that each insulation board is set into 3No. rows of adhesive. At perimeters the adhesive is increased to 4No. rows per board to ensure effective resistance to wind uplift. The adhesive takes longer to set than hot bitumen, and this needs to be allowed for by the installer. Factory Applied Bitumen Adhesive Bauder DS1 DUO vapour barrier has strips of bitumen adhesive factory bonded to its uppermost surface, covered with a thin polyethylene film to prevent it sticking to itself inside the roll. Once the product is installed, the surface can be heated with the flame of the gas torch causing the polythene to disappear and the adhesive to become activated. The insulation is then placed into position immediately, and a strong bond is achieved instantly. Cold Roof Specifications The membranes should be laid in the direction of slope, working up the slope. The head of the capping sheet must be mechanically fixed through to the deck using 5 fixings at 200 mm centres. The fixings must be large headed galvanised clout nails or screw fixings incorporating load spreading washers, suitable for the substrate to which they are being fixed. The fixings will be covered within the head lap joint by the tail of the following sheet. Warm Roof Specifications In a warm roof situation it will be necessary to securely fix timber battens across the roof at 90° to the direction of the slope ( before installing the vapour barrier) in order to provide mechanical fixing points for the capping sheet head laps. The battens should be the same depth as the insulation thickness and at least 50 mm wide. The membranes should be laid in the direction of slope, working up the slope. The head of the capping sheet must be mechanically fixed using large headed galvanised clout nails through to the timber battens using fixings at 75 mm centres in 2 rows with 50 mm between rows. The fixings will be covered within the head lap joint by the tail of the following sheet. Sectional Diagram showing layout of capping sheet ( for systems that utilise 5m long capsheets), fixings and fixing battens on roofs between 5° and 60° pitch. Decking, vapour barrier, insulation and underlayer not shown for clarity. SLOPING ROOFS ( OVER 5 ° ) Fixing Battens 2 rows of fixings Capping Sheet 4.9m Batten Centres 100 mm 50 mm 50 mm 5.0 M 25 mm