onshore vs. offshore brian hubbs, Peng, bep, and james higgins rdh building engineering Ltd.

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1 onshore vs. offshore curtain WaLL SySteMS brian hubbs, Peng, bep, and james higgins rdh building engineering Ltd. 224 West 8th Ave., Vancouver, BC V5Y 1N5 Phone: Fax: S y m p o S i u m o n B u i l d i n g E n v E l o p E T E c h n o l o g y o c T o B E r h u B B S a n d h i g g i n S 1 0 5

2 abstract The popularity of Asian (offshore) glazing systems has risen dramatically in the past few years. They can offer economic advantages on large projects as well as advanced features not available domestically. While the quality and delivery of offshore products can be on par with the best domestically produced systems, there are also companies offering products that do not conform to domestic standards and codes. The most common advantages and pitfalls of using offshore glazing systems are presented through the authors own experience on projects. The process of using offshore glazing systems is examined from the early planning and selections stages through product manufacturing, testing, and installation. The design team and glazing consultant will face cultural, economic, and technical challenges when using offshore glazing systems throughout the project. These challenges include supplier duties and tariffs, hardware issues, cloning, language barriers, differences in test lab procedures, health and safety considerations, and field review and verification requirements. Risk mitigation recommendations are presented herein for each of the challenges faced and aims to provide a roadmap for the successful implementation of offshore glazing systems in North America. SPeaKer brian hubbs, peng, bep rdh building engineering Ltd. BRIAN HUBBS has over 25 years experience as a consultant practicing exclusively in the field of building science. He is recognized by his peers as being a practical building science engineer and researcher who consistently delivers innovative solutions. He has a unique blend of theoretical and hands-on knowledge gained from completing hundreds of building enclosure investigations and rehabilitation projects, as well as from design consulting and construction review of building enclosures for new buildings h u B B S a n d h i g g i n S S y m p o S i u m o n B u i l d i n g E n v E l o p E T E c h n o l o g y o c T o B E r

3 onshore vs. offshore curtain WaLL SySteMS BACKGROUND Offshore glazing systems are becoming more common in North American building markets as more large-scale buildings utilize curtain wall systems as the exterior cladding. Glazing systems manufactured and often assembled in Asia are generally cheaper than North American systems, are often available in a wider selection of products, and can offer greater design and manufacturing flexibility. The cost savings come from lower material and labor costs, a larger bidding pool, and a larger production capacity. The challenges of adapting the offshore glazing systems to North American climates and standards increase the need for consulting, installation, and in some cases remediation expertise on these projects. OFFSHORE CHALLENGES Import Costs Many offshore glazing systems are subject to import duties and tariffs. The actual amount is dependent on the company, the country of origin, the destination country, and the amount of assembly performed prior to importation. Duties and tariffs can change at any time, and this can significantly affect the economics of the entire project. It is important to understand the current and expected duties and tariffs for each manufacturer in order to compare the real costs of the contract and ensure that each offshore manufacturer s takes on the risks associated with changes in import duties and tariffs so that they are not passed on to the owner. Shop Drawings Initial project challenges can arise from the manufacturer s being unfamiliar with the local standards, codes, and climate. Where a North American manufacturer s experience may lead to an understanding of the inherent challenges of the local standards, such as the need for rainscreen design in the rainy climate in the Northwest U.S. and Canada, many Asian manufacturers often have much of their experience focused on hot desert climates, which have their own unique design requirements. Selecting or developing a glazing system appropriate for the local climate conditions is critical to the success of the shop drawing process. If a new glazing system is being developed for use in North America, local consultants and offshore designers will need to agree on the basis of design before shop drawings are started. However, even with a good understanding upfront, it has been our experience that the shop drawing review process is considerably more onerous, requiring two to three times the number of shop drawing submittal reviews, compared to an experienced domestic manufacturer, before all significant issues are resolved. The cost of this additional effort should be considered when comparing overall system costs. Supply Model Different supply models can be used to reduce the risks of using offshore glazing systems. In the first model, an offshore plant will manufacture and completely assemble the curtain wall or window wall system; the product is shipped and then installed by local installers. In the second model, the system is partially manufactured and partially assembled offshore, with a local supplier completing the assembly, generally using North American hardware and North American insulated glazing units (IGUs). Alternatively, the glazing system components can be imported individually and used to completely fabricate the system domestically. Figure 1 Broken hardware found on-site after installation. Figure 2 Bundles of broken operable vent hardware from a single floor. S y m p o S i u m o n B u i l d i n g E n v E l o p E T E c h n o l o g y o c T o B E r h u B B S a n d h i g g i n S 1 0 7

4 Figure 3 Six-story indoor four-sided test wall located in a large plant in Shenyang, China. Insulated Glass Unit (IGU) Selection Another potential challenge with offshore glazing systems is their use of offshore IGUs. The IGU glass production and assembly factories overseas can range from state-of-the-art plants using high-end production tools to plants using sawhorses and manual caulking guns. To reduce the risks associated with IGUs, control the supply chain and specify coatings and glass from a known manufacturer that has a modern production facility. Visit the IGU factory to review the fabrication process. Pay special attention to glass cleaning, low-emissivity coating edge deletion, and the continuity of the primary and secondary sealants. Review the IGUs again during installation to verify the work has remained consistent throughout fabrication. Note that offshore IGUs are available in a range of colors and coatings that are often not possible to match in North America. This can lead to difficulty if glazing replacement is needed during the life of the glazing system. A reliable solution is to order sufficient extra IGUs to be shipped and stored locally or select glass colors and coatings that can be replicated domestically. tently the least reliable component of the glazing system. The failures often come from the use of plastics and metals not suited for the mechanical stresses associated with operable units. In a single building in Vancouver using offshore curtain wall, over 100 pieces of hardware broke during the initial installation and commissioning. Figures 1 and 2 show examples of the broken hardware collected on-site. There are two Hardware Offshore manufacturers will often offer hardware designed to replicate well-known Italian or German hardware. In the authors experience, replica hardware is consisways to reduce the risk associated with hardware. The lowestrisk option is to specify brand-name hardware from manufacturers in Italy, Germany, or North America and ensure that it is used. This will ensure that the moving mechanisms that require durability and longevity through continued use will remain working for the desired service life. Alternatively, a viable, lower-cost option is to select from the standard hardware that is offered with the glazing system and has been used many times before. This hardware should then be tested to meet the required durability standards, and samples of the products should be reviewed and installed in test mock-ups. Standards and Testing Building codes require conformance to the AAMA/ WDMA/CSA 101/I.S.2/ A440 standard, or the North American Fenestration Standard (NAFS) for applicable glazing systems. Fenestration specifications will also require testing using American Society for Testing and Materials (ASTM) and American Architectural Manufacturers Association (AAMA) standards, as well as Insulating Glass Manufacturers Alliance (IGMA) standards for insulated glass units (IGUs). The problem is that very few offshore manufacturers have access to labs with CSA, WDMA, AAMA, or IGMA certification. At the very least, test labs must be certified by a standards organization recognized by the local governing laboratory accreditation organization (for example, the Standard Council of Canada [SCC]). Accreditation is gained through international reciprocity agreements for similar standards in other countries. In China, it is the China National Accreditation Service for Conformity Assessment (CNAS) with agreements reached through the International Accreditation Forum (IAF). Testing completed in labs not recognized by the local accreditation organization will not be valid and may have to be redone domestically. Tight construction schedules and lower testing costs may mean it is more efficient to test offshore. A shipment of curtain wall or window wall will take at least a month to arrive by boat from China and then will have to be assembled and tested locally. Any issues found during testing will then have to be relayed back to the manufacturer, and the entire process starts again. Several large offshore manufacturers have their own dedicated testing facilities located near or in the plant. It is critical to ensure that these facilities are independently operated and certified to avoid a conflict of interest. Figure 3 shows an example of a large test facility located at the manufacturer s factory in China, and Figure 4 shows a typical testing facility in North America. The most important benefit of testing offshore is that the manufacturer gets to see Figure 4 ATI s outdoor multistory test wall in Fresno, CA h u B B S a n d h i g g i n S S y m p o S i u m o n B u i l d i n g E n v E l o p E T E c h n o l o g y o c T o B E r

5 and understand the consequences of his or her design and installation decisions and methods firsthand. The most significant disadvantage of testing offshore is that the installation is often performed by offshore installers who will not be present when the system is installed domestically. Testing of the curtain wall system represents a unique opportunity for the glazing contractor who has been awarded the project to get familiar with the system, train installers, and examine the sensitivity of the system to installation procedures. When testing offshore, the glazing contractor who has been awarded the project should be intimately involved with the installation of the test mock-up and be present during the testing. If this is not possible, consideration should be given to constructing and testing a mock-up onsite prior to the start of full-scale installation. Despite internationally recognized accreditation, test procedures must still be verified and checked by the curtain wall consultant and architect at the offshore test lab. In general, testing should be completed with consultants present. It is more important to understand failure mechanisms and the repair strategy than to simply obtain a pass/fail rating. Therefore, testing should not be allowed prior to the formal test date unless the consultant team is present. Figures 5 and 6 are from a project where previous testing had obviously been performed prior to the formal test date, complete with short-term modifications made Figure 7 Window wall frame constructed with weep holes at extrusions on all sides of the window opening. to enhance performance. When the system was returned to its unadulterated state, the test sample failed to meet the water penetration test. Communication and Culture In dealing with offshore manufacturers, the language and/or cultural barriers can have a significant impact on the relationship when addressing technical challenges as they arise. Specify that technical communications, both verbal and written, be in English. A technically competent translator, fluent in both languages and who has worked in Asia and North America, is vital to overcoming issues at technical, design, and testing meetings. Nontechnical translators can be invaluable at other types of meetings and during social interactions, but they are not able to accurately translate technical discussions. It is important to recognize cultural differences. Where a technical issue or manufacturing mistake in a North American plant can be seen as a good opportunity to find a solution and address the problem permanently, in some cultures it can be seen as Figure 5 Wet goop wiped off operable gaskets prior to testing for water penetration. Figure 6 Open bucket of petroleum jelly compound sitting near the test specimen. a serious threat to the integrity and honor of those involved. The process for finding a solution or tracking down the origin of a defect should allow all parties to save face and to proceed in a manner that does not focus on placing blame. PLANT VISITS Taking any and every opportunity to visit the offshore manufacturing plant prior to shipment overseas can mean the difference between having to fix a flaw discovered while the product is still in the plant or discovering the issue many months later onsite and having to remediate in-situ. Quality control and quality assurance review work starts in the plant where concealed seals, materials, drainage planes, and fasteners are visible and deficiencies can be corrected immediately. In offshore plants, deficiencies are primarily systemic errors caused by incorrect instructions or poor setup, which leads to identical repetition of the same mistake, resulting in large remedial costs if the S y m p o S i u m o n B u i l d i n g E n v E l o p E T E c h n o l o g y o c T o B E r h u B B S a n d h i g g i n S 1 0 9

6 Figure 8 Spandrel back pan fully welded on all edges, ground smooth, and painted. repairs are not corrected in the factory. Figure 7 shows an example of a systemic error found in the plant due to incorrect instructions and a lack of understanding of interior drainage requirements for glazing systems. The plant visit can also showcase some of the strengths and technical advances of the offshore plants. Where a North American plant may aspire to achieve efficiencies by reducing the work required for each component, the offshore plants can spend more time on each component, mainly due to reduced labor costs. Figure 8 shows an example of a component that requires multiple extensive manufacturing steps to reach completion. While many offshore facilities visited by the authors are well-run and meticulously organized (Figure 9), the physically massive manufacturing plants can be prone to fewer safety precautions and less hazard awareness (Figure 10). It is important to stay aware of the surroundings at all times, and it is a good idea to bring personal safety equipment and not to rely on the plant safety standards alone. ON-SITE CHALLENGES When the glazing system finally arrives at the construction site, check it to ensure the product supplied is the same as the product tested and reviewed offshore. On a large project with a tight construction schedule, the glazing system will come in several shipments spanning over many months. In that time, small changes in the glazing system can occur due to availability or unavailability of materials and components, as well as high staff turnover. It is important to continue to review each new shipment for manufacturing consistency. If factory visits have not been performed, partial disassembly will likely be required. In one case, on a high-rise building in Burnaby, BC, a key structural component in the head of the window-wall system in the second shipment was found to be substantially different from the component found in the first shipment and shop drawings. The change required verification that the new design would meet the structural requirements. As a result, samples of the second batch of window wall had to be tested locally. CONCLUSION It is inevitable that offshore glazing systems will be used, as their perceived economic benefits and technical capabilities are widely recognized. When offshore systems are considered, a specialty curtain wall consultant with direct experience with the proposed systems and country of manufacture should be retained from the early planning stages through to construction completion. Once a manufacturer and system are selected, the specialty consultant, architect, curtain wall designer, and local installers need to work as a team to design, test, and manufacture the system successfully. This will inevitably require trips to witness testing and manufacturing offshore; consideration of cultural, language, and economic factors; as well as continuous diligence regarding quality and consistency. Once on-site, the focus shifts to the installation; however, continuous quality assurance checks of the system during installation are also required to ensure that the installed product meets the project requirements and has not changed from the tested configuration. This methodology will help to ensure the successful implementation of offshore glazing systems in North American projects. Figure 9 A large plant floor with organized and well-kept workstations. Figure 10 Workers assembling mock-up without appropriate footwear or head protection h u B B S a n d h i g g i n S S y m p o S i u m o n B u i l d i n g E n v E l o p E T E c h n o l o g y o c T o B E r