Architectural Envelope Experts
Table of Contents Company Introduction
Introduction to Aluminum Division
Sustainability in Production and Design
The Principles of Faรงades-Design
Expected Technical Work Output Chart
Derivatives and Expected Deliverables: Schedule
Cladtech International Green Building Agencies
Cladtech International is the regionâ€™s leading building envelope specialist. Backed by Al Rajhi Holding, a distinguished building solutions firm, we strive to provide our clients with comprehensive answers to their needs. Our vertically integrated business structure, including design, development and processing capabilities, allows us to meet all your construction requirements. The Aluminium, Metals, Cladding and Glass divisions offer a full range of services including the very best in customer care. No project is beyond our capacity and we can respond to any challenge. The companyâ€™s skilled craftsmen are capable of producing more than 600 bespoke, unitised wall panels per day to the highest standard of quality. Using the latest technologies and techniques, they ensure that Cladtech products continue to enjoy a reputation for excellence. Line managers and quality control officials carefully check every step of the production process, making certain your products arrive in perfect condition. Installation professionals are available to assemble them into a customised whole. Expert teams of engineers and consultants can enhance your project with unique integrated solutions through value assessments and site management. Competitive pricing and built-in cost savings will ensure the success of your venture in both the short and long term. Cladtech. We are the solution.
INTRODUCTION TO CTI ALUMINUM DIVISION
INTRODUCTION TO ALUMINUM DIVISION
Cladtech InternationaI are specialists in the design, manufacture, and installation of aluminium curtain walling, windows and doors for every type of commercial and residential building. CTI are equipped with a comprehensive range of modern technology in aluminium fabrication. CTI’s new factory is designed to take full advantage of modern mass-production techniques to ensure highest levels of accuracy combined with high outputs at optimum cost. All design-work is generated in-house and all installation-works are handled by CTI’s Contracts Department including all labour and project management on site. This detailed integration of personnel and plant is a guarantee of CTI’s capacity to deliver even the most complex orders in a timely and efficient manner, and to the standards specified by the Client. Curtain walling techniques have been used to cover the structural skeletons of high-rise buildings for over a hundred years. Up to around 1960, steel (probably galvanized) was the most commonly used material prior to the arrival of massproduced aluminium extrusions in the USA. The most famous pioneer of aluminium and glass curtain wall technology was the American Architect, Mies Van Der Rohe, who recognized the colossal advantages of creating a building envelope using these materials. Van Der Rohe described curtain walls as “LESS IS MORE”. And today, at CT international we are committed to this philosophy that curtain walling is still the most cost-effective way to clad the exterior of a building structure and to maximise the rented floor space for the developer. Curtain walling is a grid (sometimes quite massive) of thousands of metal components whose joints are formed mechanically, that-is-to-say they are not welded. This system of mechanical connection is designed to allow for all kinds of differential movement over the life of the curtain wall including thermal expansion and contraction, wind loads, building movements and seismic effects. Nevertheless, the curtain wall’s main function is to protect the interior of the building from air and water penetration and so we can begin to appreciate the complexity of creating a cladding system which can move and yet maintain a high level of indoor comfort. How is this done? Curtain wall is designed on the principle of allowing air and water to partially penetrate the system and then to get rid of it by means of pressure-equalised drained joints. Each curtain wall panel or frame-member is designed to interlock with it’s adjacent components to create a grid of enormous strength ▲
INTRODUCTION TO ALUMINUM DIVISION
when attached to the underlying building structure, while
any localized build-up of air pressure which might force it’s
allowing independent movement.
way (together with water) through the inner seals and, thus,
These principles acknowledge the need to provide a building envelope which is, as far as possible, wind-proof, rain-proof but remains light and elegant, thereby enhancing the aesthetic appearance of the building. Frequently, the curtain wall is what we actually see (mainly) when we look at a typical modern structure. CTI recognize that, in spite of every reasonable effort to prepare the joints in the facade, it is likely that water way penetrate at some location. This may be due to loss of adhesion in the
into the building, Small openings, formed as notches, in the joint-cavities allow water to drain horizontally left and right to be carried down through the mullions and ultimately to the exterior. Thus, the interior seals are not compromised, and the rain screen system is able to perform it’s function which is to protect the indoor environment. As expected, the success of the system depends on accuracy of fabrication and installation which depends on the high level of professional attention to detail at CTI.
sealants, or through gaskets which have become partially
The design requirement for cutting and machining of extrusions
dislodged, possibly during installation, or subsequently. Since
are prepared using Cad/Cam software which is integrated with
there will be (potentially) many linear meters of joints in the
the factory equipment and directly programmed to carry out
surface of a major curtain wall, CTI curtain walls are designed
all cutting and machining operations. On loading any particular
on the “Rain Screen” principle which allows for some random
extrusion to the production line, the operation is substantially
water-penetration through the external seals.
automated through to completion of the manufacturing
Following from this, CTI curtain wall systems incorporate
“pressure equalisation” which is a technique to neutralize
Seagram Tower, New York, 1958. Mies Van Der Rohe and Philip Johnson "Less is More" ■ 55
Design Office Employs specialized computer-assisted drafting and design software for:
• Curtain wall and window wall systems
• Glass walls
• Structural steel
• Natural stone cladding
• Precast concrete
• Water proofing
• Metal stud systems
• GFRC Systems
• Mock-up drawings
• Installation Diagrams
• Complete structural analysis and design including windload engineering
• Evaluation and testing of materials
• Evaluation of structural integrity of proposed design solutions
• Buckling and stability analysis for façade designs
• Finite element analysis
• Large deflection and membrane stress analysis
• Thermal stress analysis
• Thermal transmission analysis of glazed aluminium façades.
New Systems Design and Development
• Purpose-made and standard curtain walls
• Stick system
• Bolted frameless glass facades with
glass fins, stainless steel spider- connections, patch-fittings etc
• Structural silicone glazing
• Window designs
• Sliding glass doors
• Sloped glazing and sky lights
• Cladding in a wide variety of materials
• Roofing and water proofing
Research and Development
• Structural silicone testing
• Splice designs
• Expansion joints
• Adhesive anchors
• Mechanical anchors
• Gasket designs
• Blast resistance
• Hurricane resistance
• On-going development of Co. QA/QC procedures.
Cladtech International design engineers become involved with the project architect and work closely with him from the earliest concept stage of the project and through the many steps required to start the delivery process. We are able to develop practical and cost-effective design solutions which take full account of aesthetic and performance requirements. All of this detailed interaction between us and our Partners/ Clients is based on solid design and engineering principles from our in-house resources. In addition, CTI can produce value engineering experience to ensure that all engineering proposals and solutions are not over-designed and are kept within the project budget, but without compromise to safety and long-term performance. CTI are able to provide this strong advisory role across their entire product range.
SUSTAINABILITY IN PRODUCTION AND DESIGN
Cladtech International has a strong belief in, and an equally strong commitment to the principles of sustainability in all our corporate activities. We thoroughly implement these principles both internally as well as in our total interaction with suppliers and clients at all levels. It is our clear objective to exercise caution at every stage of our processing, administration, manufacture and installation, in order to minimize human impact on the environment. As specialists in the provision of materials and systems to form the building envelope we are concerned to achieve a deep understanding of the total performance of our work in the terms if energy efficiency, indoor comfort, daylight and views and avoidance of condensation. These are the fundamentals of good sustainable design for the 21st century and we believe that our highly qualified teams have the experience and knowledge to support sustainable design and product-quality at least equal to the best.
Façade Engineering Services The building envelope is a key element in the creation of the built environment. The selected cladding system at the heart of the building fabric (Stick, Unitized, or Double Skin) must perform a number of critical tasks without fail, namely:
To – Filter light
To – Moderate heat
To – Block infiltration of air and water
To – Enhance life cycle cost-benefit to the client
CTI provide the following services to the achieve these goals:
– Research, development and design
– Performance testing
– Thermal analysis
– Code and authority compliance.
Our main focus is on practical and buildable solutions which can be efficiently realized by the State-of-the-Art equipment and technology and by our experienced design and production teams.
Structural design is an engineering process to determine all the “fail safe” aspects of a structure exposed to the most severe and dynamic forces of nature. All buildings are subject to movement, and the façade engineer must predict and confirm the effect of complex building motion in relation to the equality complex motion of his materials which all have different coefficients of linear expansion and contraction. Façade engineering is a specialized link between Civil Engineering and Architecture, and at Cladtech International, we bring this expertise to our industry as specialists at this critical interface, in all our project-work. The structural design of the façade works at:
– Wind load deflection calculations.
– Glass strength and deflection calculations.
– Fixing methods.
– Sealant application and gasket design.
– Ease and efficiency of installation.
– Method statements.
In addition to the above, the structural design team must assess the overall thermal performance of the façade with regard to system U-values and glass performance. Cladtech International undertake thermal modeling studies to ensure that their metal works conduct the minimum amount of heat to the structure and the room-interior even under the most severe solar exposure. Cladtech International also bring their expertise in glass to produce high performance glazing products, in-house, to meet the requirements of the project specification and to minimize direct solar heat gain. In particular, our design team has to ensure the CTI glass has an SHGC (Solar Heat Gain Coefficient) to conform with the calculation by the Project Mechanical Engineer for the capacity of the air-conditioning equipment. Finally, the structural design team must be aware of all the current Green Building rating systems and municipal building codes which are now in use throughout the Gulf region. This is of particular importance for projects which require LEED or Estidama Certification which apply to our industry.
THE PRINCIPLES OF FAÇADE-DESIGN
"LESS IS MORE" The principle of attaching a glazed aluminum framework to a concrete or structural steel skeleton was perfectly demonstrated in 1958 by Mies Van Der Rohe and Phillip Johnson in the famous 38-storey Seagram Tower, New York, which is still in perfect condition today. By means of highly durable bronze anodized extruded aluminum profiles attached to galvanized steel brackets, it was possible to create an elegant fully glazed building envelope which also allowed the owners to maximize the use of the floor space.
"STICK" SYSTEM CURTAINWALL Essentially, the “ Stick Curtainwall System” is constructed on site using aluminum profiles to create a grid of transoms and mullions all mechanically connected. The majority of the work is ex-factory and the installation starts at the bottom of the façade and proceeds upwards. Aluminum components are attached to galvanized steel brackets which have been accurately pre-fixed to the structure. Stainless steel screws and bolts are used in order to prevent anodic reaction between steel and aluminum. Stick System Technology is relatively simple and competitive, although its competitiveness today is somewhat offset by relatively high labour cost and slow pace of installation. All glass has to be installed on site and extreme care must be exercised to ensure that all joints are perfectly sealed with appropriate materials. In general, it is more difficult to incorporate “rainscreen” principles and pressure equalization into a typical stick system design. Furthermore, this type of curtainwall construction may require external scaffolding and this will, for practical purposes, limit the effective height of the façade. It is not an appropriate technology for “fast track” construction schedules and progress can also be negatively affected by adverse weather. In terms of aesthetics, the stick system depends on pressure-plates to contain the vision glass and the spandrel panels. The pressure-plates, in mill-finish aluminum, have to be concealed by “snap-on” covers which project beyond the plane of the glazing and are a strong visual characteristic of the system. A provision of weep-holes and drainage-slots is included to allow water to drain to the exterior. ▲ 13
PRINCIPLES OF FAÇADE-DESIGN
STRUCTURAL SILICONE CURTAINWALL In today’s architecture, the main preference is for “flush glazing” in order to avoid the solid appearance of the standard stick-system grid. Thus, the stick system can be adapted to a modification where the same millions and transoms are bolted to the structure, but the glass and spandrels are factory-assembled into aluminum “carrier frames” which are clipped into place on site. The advantages are:
– All panels can be flushed-glazed off site using structural silicone sealant.
– Site work is reduced.
– Installation programme accelerated.
– Openable windows and insulated spandrel panels can be accommodated.
– Frameless appearance achieved.
PRINCIPLES OF FAĂ‡ADE-DESIGN
TW0 (2) SIDE STRUCTURAL CURTAINWALL This is a popular curtainwall solution which employs pressure plates and snap-on covers for the transome joints and structural silicone for the mullions, thus providing flush glazing whilst using the horizontal covers as a mainly decorative feature. Overall, the stick system curtain walling, still has a useful position in contemporary architectural design, particularly for low-rise buildings, and is a mature engineering concept which has evolved over 50 years as a reliable and costeffective building envelope.
PRINCIPLES OF FAÇADE-DESIGN
UNITIZED (ON-LINE) CURTAINWALL The astonishing progress in the design and construction of very high-rise buildings over the past 25 years has called for considerable innovation in the means of making and installing the building envelope. Today, and no doubt in the future, glass and aluminum will feature as the dominant materials of choice to satisfy this “love affair” with glazed façades. The combination of taller buildings, faster construction schedules and rising labour costs have lead to the development of cladding systems which are substantially built off-site and which are designed to the accelerate installation productivity on site. The unitized system curtain walling is logical response to these demands and brings the benefits of mass-production into play. Unitization also makes use of advanced labour practices in fabrication and supervision resulting in output of high quality, close tolerances and fast efficient delivery. For buildings higher than 20 floors, unitized curtainwall panels can be attached by operatives working at the edge of the slab in conjunction with a skilled crane operator. All seals and gaskets are pre-installed and the connection of one panel to its neighbour provides pressure-equalised selfdraining properties according to the “rainscreen” principle to ensure no infiltration of air or water to the interior of a building, and that smoke / fire-stop materials are correctly and accurately positioned. The system can accommodate openable windows and spandrel panels with insulated back-pans.
PRINCIPLES OF FAÇADE-DESIGN
CTI GLASS AVAILABILITY IN GB SECTION DOORS AND WINDOWS For virtually every type of building, CTI are able to offer a very broad range of hinged and sliding aluminum doors and windows. The use of robust hardware and well-designed extruded aluminum profiles gives the CTI range of doors and windows a combination of quality, serviceability and durability to perform at maximum efficiency in the most challenging environments. Door and Window glazing is mainly sourced from CTI glass division and includes tempered and laminated safety glass as well as insulated glass units.
BOLTED FRAMELESS GLASS FAÇADES CTI are able to undertake full design, fabrication and installation of bolted glazing systems incorporating stainless steel patch-fittings, glass fins, spider connectors and a very large combination of tension-rod designs. CTI bolted glazing can be single or double glazed with sourcing of structural tempered, tempered-laminated, and tempered-laminated insulated units from CTI's glassprocessing division. CTI are also able to undertake are all types of frameless tempered glass for shop-lifting and partitions including a wide range of frameless glass doors with standard or customed-designed metal hardware
Double Skin Façades The principle of this technology is to provide a glazed façade in which two separate glazed aluminum walls are constructed with a large space between them. The interspace contains an openable blind system which can be remotely controlled by a photo electric switch reacting to ambient daylight / sunlight levels. Cooling of the interspace is done mechanically using low-voltage extractorfans located above the false ceiling, and, in some designs, return the air back to the bottom edge of the curtainwall via hollow-core concrete floor slabs. Glazing in this type of system generally comprises a clear, or light reflective, single glazed outer skin and a clear IG unit with a low – E coating on surface # 2 as the inner skin. It is effectively a triple-glazed system in which solar control is achieved by the internal blinds. There are no openable windows in the system and all room and inter-space ventilation is done mechanically. Although coming at a relatively higher cost, double skin façades claim to be cost-effective by providing high levels of daylight and insulation due to their sophisticated control mechanism.
EXPECTED TECHNICAL WORK OUTPUT CHART
1. – ARCHITECTURAL
2. – STRUCTURAL
– Embeded layout
– Bracket Detail
CONCEPT / SYSTEM DRAWINGS
– Cast in
– Panel layout and I.D.
DERIVATIVES AND EXPECTED DELIVERABLES: SCHEDULE
TENDER STAGE DERIVATIVES
• Architectural drawings/input
– Plans – Section – Elevation – Details – Perspective
• Specification • BOQ
INTERNAL • Tender / System Design • System Drawings – Typical Plan/ section/elevation – Details – Isometric/ Perspective – Initial Project Milestone – Engineering Cost
DERIVATIVES AND EXPECTED DELIVERABLES: SCHEDULE
AWARDED STAGE DERIVATIVES
A1 • Construction Schedule • Architectural Drawings(100%) – Plans – Section – Elevation – Details A2 • Structural drawings – Floor slabs – Beam/column schemes – Walls/blockwork
A3 • Specifications drawings
A4 • BOQ (Cost/price not required
Planning Dept. B1 • Schedule Commercial Dept. B2 • Tender Drawing • Eng'g cost • Tendered Milestone Purchasing B3 • Material availability • Material cost • Material lamination • Material cost value
Technical work schedule manpower allocation
• Project milestone • System design development • Die Drawing • Structural calculation • Project specs. • Visual mock-up drawing
Fabrication B4 • Production limitation • Production cost value
• Shop drawings – Developement – Layout/module plan – Embeded layout – Panel tag layout – Joinery detail Project Management – Isometrics B5 • Method statement • Fabrication • MTO • Installation – Bulk sequence – Release • Installation/ site limitation
Depending on various parameters, the solar radiation that strikes any glass surface is partly transmitted, partly absorbed and partly reflected. Basically, the major part that is used to define the thermal behavior of curtain wall is the thermal transmittance of surface or U-value. Arithmetically, the U-value (the overall heat transfer coefficient) of material defines the rate of heat transfer through an element over a given area and under standardized conditions. The significant part of the cooling load in a building is due to solar heat gains subject to the area of the faรงade cover. So the thermal constraint in designing the faรงade in hot regions is on how to minimize the solar heat gain. On the other extreme end of building envelope design, the heating load of a given space, in cold climate region, is highly influenced by the proposed envelope. For the above major reason, thermal analysis of curtain wall is carried out analytically. The output of the analysis finally reflects the heat exchange phenomena between the two separated environments and measures the thermal efficiency of the system. As part and parcel of the structural verification CTI carries out the representative thermal analysis for all systems adopted in a project.
CLADTECH INTERNATIONAL AND GREEN BUILDING AGENCIES
Sustainable Façade Design It is an alarming fact that the UAE has one of the world’s
three critical aspects relating to the design of the building
largest per capita carbon footprints, and is among the top three
countries for GHG emissions.
1. Energy and atmosphere.
2. Daylight and views including indoor air quality.
3. Regional sourcing and recycling of materials.
Our cooling dominated environment, ultra-low rainfall and minimal cloud-cover result in an extremely high demand for airconditioning and water. Over 70% of the power generated in
Together, these three categories can potentially account for
the UAE is for cooling.
over 45% of the points required to achieve a LEED Platinum
Considering that the main source of heat gain is through
or a 5-Pearl Estidama sustainable design rating.
the window, it can be seen that thermal efficiency and solar
Cladtech International is well placed to enable it’s clients
resistance are of paramount importance in the design and
to earn valuable points at every level of Green Building
construction of modern façades.
Certification as a result of:
In recognition of the urgent need to raise the standard of building design in our region there is now a growing adherence by developers, government agencies and designers to the principles of the LEED Green Building Rating System. LEED (Leadership in Energy and Environment Design) is a guide to sustainable design and is, at the option of the client, a certification process at various levels of compliance which are:
– Thermally efficient designs.
– Locally-produced extrusions and gaskets.
– Locally-produced float glass.
– Locally-produced solar reflective and low – E glass.
– In-house glass processing.
– In-house anodizing and powder coating.
– Recycling of metal waste.
– Partial re-cycling of glass waste.
1. Certified only
2. Silver grade
Furthermore, CTI engineers are well-qualified to work with
3. Gold grade
architects and LEED AP’s (Accredited Professionals) and
4. Platinum grade
Estidama AP's to assist in the achievement of competent
Recently, the government of Abu Dhabi has established the Estidama Pearl Green Building Rating System which has been created with special attention to Gulf Environmental Conditions.
sustainable façades which, potentially, can make a significant contribution of the UAE’s progress in lowering GHG emissions and shrinking it’s swollen national carbon footprint.
Estidama is a guide to sustainable design and, like LEED, is certifiable according to Pearl Awards at the following levels: 1. Pearl (least stringent) 2. Pearls 3. Pearls 4. Pearls 5. Pearls (most stringent) The government of Abu Dhabi has ordered that all new Government buildings must be designed at least up to 2 Pearl standard. Both LEED and Estidama are strongly supported by the current American ASHRAE 90.1 Standard. LEED and Esitidama place a high degree of importance on
UAE : Tel.: +971 7 244 61 14 Fax: +971 7 244 61 12 P.O. Box 6674 Ras Al Khaimah, UAE
KSA : Tel.: +966 (1) 219 05 66 Fax: +966 (1) 293 57 52 P.O. Box 18927 Riyadh, KSA
Published on Jun 3, 2012