COSMOFIN FG Welding Guidelines

Transcription

1 COSMOFIN FG roofing membranes can be welded homogeneously to produce a permanently waterproof seal using hot air and solvent welding (diffusion bonding) processes. It is preferable to weld larger seam lengths using hot air welding with a wheeled welding machine (e.g. Leister Varimat). However, it is also permissible to weld the seams using solvent welding. Detailed work should preferably be completed using hot air welding equipment. Before starting the welding work, welding tests on the relevant substrate should be completed to check the quality of the weld. Welding speed will depend on the outside temperature and air humidity. The Installation Guidelines for COS- MOFIN FG should also be observed in addition to these guidelines. Hot air welding In the case of hot air welding, welding machines or hand held welding equipment with temperature regulation and measurement of the temperature at the nozzle should be used. 4. Fluctuations in voltage caused by long power supply lines or other site conditions can lead to different welding temperatures and thus to varying quality of the welded seams. This should be avoided by the use of higher amperage power leads. In general, an independent electrical circuit is required for each piece of welding equipment. This may require the use of portable power generators (minimum 3 kva -15 Amp output). 5. The roofer must have the required minimum level of knowledge and skills for welding and installing synthetic membranes in accordance with the latest technical standards. 6. Different material thicknesses and changing climatic conditions will result in different welding temperatures and welding speeds. Therefore, a test weld should be carried out on the original substrate before starting work. Once the welded seam has cooled down, visually inspect the quality of the seam and test its strength using peel or probe testing. Check the quality of the welds regularly. 7. If using a welding machine without a caterpillar drive, the use of a so-called welding aid may be necessary to ensure the crease-free installation of the membranes. Requirements The membranes to be welded must be dry and free of dirt, dust and residual adhesive. Based on the conditions at the construction site, the following should be observed for hot air welding: 1. The welding temperature is dependent on the welding equipment, the welding speed, the substrate and the weather conditions. 2. Avoid overheating the seam because this could weaken the membrane material and cause degradation of the seam strength. 3. The welding process must be carried out using sufficient contact pressure. If using a hot air welding machine, it may be necessary to add additional weights to the machine. The pressure resistance of the insulation material must correspond to the required contact pressure during welding, as well as to the instructions issued by the relevant manufacturer. Automatic welding The relevant operating instructions issued by the manufacturer must be observed. For the purposes of guidance, the following settings for the temperature and feed rate have been ascertained through internal welding tests carried out at room temperature (20 C). The values stated below should be understood as guidance for setting the optimum welding parameters and do not absolve the roofer from their responsibility to complete the necessary welding tests at the construction site. Changes to the outside temperature, air humidity, substrate and wind or sun can change the following parameters. Name of Temperature Feed rate equipment Varimat V 520 C 2.2 m/min Varimat V2 520 C 3.3 m/min Hand held welding equipment In general, it is recommended that infinitely variable hand held welding equipment with a temperature display and PID control is used. The nozzle width on hand held welding equipment for welding seams should be 40 mm. For detailed work, a 20 mm wide nozzle is also required. Remove combustion residues at the WOLFIN Bautechnik GmbH Page 1 Version: 06/2016

2 nozzle outlet regularly with a brass wire brush. In order to achieve sufficient contact pressure in the seam area, a pressure roller made out of silicone rubber is required. The roller should have a diameter of approx. 32 mm and a width of approx. 43 mm. Welding technique: The individual membranes are rolled out to release any tension and overlapped by at least 50 mm. The temperature on the welding equipment is set to between 450 C and 470 C. The welding work is carried out in three stages: 1. Tacking the seam The seam is tacked to avoid the overlapped sections of the membrane moving during the welding process. 2. Pre-welding Pre-welding creates a barrier and prevents the loss of heat. An unwelded seam should be left free in front of the pre-welded section: mm when using a 40 mm nozzle mm when using a 20 mm nozzle Final welding The final welding stage must result in an airtight and watertight seam. The individual membranes are joined together through the plasticizing of the welding areas as a result of heating. A homogeneous seam is achieved by immediately pressing down with even pressure on the seam area using a pressure roller that is moved in parallel to the nozzle. Crease marks in the seam should be avoided at all costs because they could lead to capillaries. Solvent welding: The membranes to be welded must be dry and free of dirt, dust and residual adhesive. The solvent welding agent can be applied at a minimum temperature of +8 C without the need for any additional measures. At temperatures below +8 C, either hot air welding should be used for the welding process or the seam area should be pre-warmed using hot air welding equipment (attention: do not prewarm the seam using a naked flame risk of explosion). All solvent welding agent containers should be kept firmly closed before and after use because to avoid moisture penetrating the container which could impair the dissolving power of the solvent welding agent and it will not be possible to achieve a permanently stable connection at the seam. In order to apply WOLFIN solvent welding agent to the seam area, use non-glued, vulcanised flat brushes or WOLFIN rapid welding brushes in combination with WOLFIN spray bottles. The regulations for occupational health and safety must be strictly observed when handling solvent welding agent. The solvent welding agent may not be mixed with another solvent. In order to avoid condensation forming in the containers, they should be stored in ventilated, temperature-controlled rooms and not outside. The containers should be protected against frost and direct sunlight. In order to achieve a homogeneous seam, the following fundamental aspects should be observed: - A quantity of approx. 20 g/m of seam is required. Avoid excessive dosing of the solvent welding agent. - It is important to achieve a straight welded seam parallel to the edge of the membrane. Avoid the formation of welded peaks in the rear welded area. - Sufficient contact pressure using a silicone roller/sand sack should be ensured. - Excess solvent welding agent should be immediately removed using a clean, white cotton cloth. Seam sealing: COSMOFIN liquid should be used to seal the welded and inspected seams at the edges. Occupational safety: Sufficient ventilation and aeration should be ensured when working with solvent welding agents in enclosed rooms. Explosion proof fans should be used. The regulations issued for the handling of tetrahydrofuran by the relevant professional associations must be observed. Welding technique: The sections of COS- MOFIN F membrane used for the connecting or detailed work or the COSMOFIN FG membranes on the surface of the roof are rolled out to release any tension and overlapped by at least 50 mm in accordance with the installation instructions. A minimum welding width of 30 mm must be maintained. WOLFIN Bautechnik GmbH Page 2 Version: 06/2016

3 The solvent welding agent is applied between the overlapping edges of the membranes using a gentle spreading motion, whereby the membrane on the top is pressed down onto the lower membrane at the same time. Fixing plates used for linear fastening in front of upstands should be kept free of solvent welding agent. chamfer plane. This process is absolutely essential for membrane thicknesses of 1.5 mm or greater. Then immediately blow hot air into the open T- joint and at the same time roll over the edge of the underlying membrane vigorously with a pressure roller. Checking the welded seams: Once the welding work has been completed, all seams need to be checked and, if necessary, reworked. The test should be carried out using a WOLFIN seam test needle that is pulled along the edge of the seam while exerting slight pressure. Polystyrene insulation: If using polystyrene insulation, damage to the insulation through heat exposure or solvent welding agent should be avoided using suitable measures e.g. sufficient overlapping of the membranes. Forming end joints It is imperative to avoid cross-joints. This can usually be achieved by arranging the membranes with a corresponding offset. Internal and external corners Injection mould parts are available for forming internal and external corners. It is preferable that these parts are installed. Welding T-joints: It is important to proceed particularly carefully in areas where multiple membranes overlap e.g. end joints (T-joints). Heat up the upper edge of the membrane in the area of the capillary. The edge of the seam needs to be chamfered in advance using a Internal corners External corners WOLFIN Bautechnik GmbH Page 3 Version: 06/2016

4 Weld the base plate to both the waterproofing membrane on the surface of the roof and the membrane collar around the pipe. Protrusions Sealing/enclosing pipes can be carried out by hand using sections of COSMOFIN F membrane cut to size. The pipe firstly needs to be enveloped with a COSMOFIN F membrane collar with the vertical overlap welded tight. A piece of COSMOFIN F membrane (base plate) with a hole 3 cm less than the pipe diameter is cut out of the middle. The upper flashing is achieved using a hose clamp suitable for the circumference of the pipe and sealed. Warm the COSMOFIN F around the hole and while still warm pull the base plate over the pipe and collar down to the deck membrane. WOLFIN Bautechnik GmbH Page 4 Version: 06/2016

5 System accessories The following products are available and should be used for the efficient and safe installation of COSMOFIN FG membranes: COSMOFIN F homogeneous membranes for detailed work COSMOFIN coated metal sheet COSMOFIN internal and external corners COSMOFIN lightning rod protection tubes Teroson AD 914 and Teroson AD Adhesive Spray for connection binding The above information corresponds to the generally recognised technical standards, as is documented, for example, in the German Flat Roof Guidelines for DIN Furthermore, they correspond to our current state of knowledge gained through the development and production of COSMOFIN FG, as well as the findings from the practical use of the product. All previous versions become invalid upon publication of these application guidelines. If any questions arise, you should seek expert advice. Technical Hotline Telephone: / Fax: / WOLFIN Bautechnik GmbH Page 5 Version: 06/2016