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No spam, guaranteed!https://www.schuettemetals.com/blogThe Concealed Safety of Curtain Wallshttps://www.schuettemetals.com/blog/postid/23/the-concealed-safety-of-curtain-wallsEmbedsWed, 15 Apr 2020 16:24:00 GMT<p>Growing up, I remember sometimes being dragged along with my parents when they went someplace boring—I was a very young boy, so I found most places dull.</p> <p>I<img src="/Portals/0/Images/Crosshair.png?ver=2020-04-14-121939-107" alt="Crosshairs" longdesc="Crosshairs" style="width: 175px; height: 175px; float: right; margin: 12px;" /> remember sitting in waiting rooms, looking out the window, and using the crisscrossed wire in the window as a cross-hair, lining up shots to imaginary bad guys, and saving the day.</p> <p>Admittedly, until researching for this article, I never knew why the wires were there and the part they played in curtain walls. In fact, over a year ago, I had never heard of the concept of a curtain wall.</p> <p>Have you?</p> <h2>What are Curtain Walls?</h2> <p><img src="/Portals/0/Images/street%20view%20of%20Curtain%20Wall.jpg?ver=2020-04-14-115252-970" alt="street view of Curtain Wall" longdesc="street view of Curtain Wall" style="border: 1px solid #000000; float: right; margin: 12px;" />A curtain wall system refers to a non-structural, outer wall. The term curtain refers to wall panels attached on the outside of the floor slabs. In layman terms, they're hung on the building just like a curtain. In most cases, large, high-rise commercial buildings use curtain walls.</p> <p>Unlike other forms of exterior walls that form a fundamental component of the building structure, curtain walls only bear their weight. Any weight imposed by external factors transfers to the main structure through the columns or floors of the building. </p> <p>Typical curtain wall installation includes encasing glass in aluminum frames, then attached to the structure using a steel anchor. </p> <h3>Curtain Walls vs. Window Walls</h3> <p>I'd like to make just a quick note about window walls. Curtain walls and window walls are members of the same family tree, although on different branches. The most significant difference between the two wall systems is how they're used. Curtain walls are commercial, whereas the residential application fits better with window walls.</p> <h2>What Do Curtain Walls Do?</h2> <p>Like any other wall, the <a href="https://ascelibrary.org/doi/10.1061/40798%28190%2913">primary purpose of curtain walls</a> is shielding the interior of the building from external factors such as wind, rain, extreme temperatures, sun exposure, and noise.</p> <p>The popularity of curtain walls increased rapidly from the 1930s when first used. Curtain walls are now a key feature in multistory buildings for many reasons.</p> <p>The most notable advantage of curtain walls is their appearance. The reflective glass surface offers a sophisticated look, significantly enhancing its visual appeal. Curtain walls are now the hallmark of contemporary city skylines, used to achieve a host of purposes, including:</p> <h3>Energy-Efficiency</h3> <p><img src="/Portals/0/Images/Sunshine%20inside%20curtain%20wall.jpg?ver=2020-04-14-115418-660" alt="Sunshine inside curtain wall" longdesc="Sunshine inside curtain wall" style="border: 1px solid #000000; width: 275px; height: 157px; float: left; margin: 12px;" />Curtain walls can be double-glazed or treated, enhancing insulation. Once enveloping a building with curtain walls, the heat is kept outside during summer and inside during winter.</p> <p>The stabilized temperature reduces the demands on the HVAC system, which then reflects on power bills. Remember, curtain walls are mostly used in high-rise commercial buildings where maintenance costs run into thousands of dollars. A wall offering a high level of thermal performance provides significant savings. It is also worth noting that building regulations have precise requirements on energy efficiency, and using these walls helps achieve the required rules.</p> <h3>Transparency</h3> <p>Curtain walls allow natural light into your space. The transparent/translucent glass helps maximize the usage of natural light, always a key consideration in any architectural design.</p> <p>Natural light instantly makes space appear larger and livelier. People enjoy wall-to-wall views. In high-rise buildings, that includes the sight of the city below in all its splendor. Letting in the sunshine also means that less electricity is needed for running the lights.</p> <h3>Design Flexibility</h3> <p><img src="/Portals/0/Images/Modern%20design%20of%20curtain%20wall%20system.jpg?ver=2020-04-14-115538-693" alt="Modern design of curtain wall system" longdesc="Modern design of curtain wall system" style="border: 1px solid #000000; float: right; margin: 12px;" />Curtain walling systems<a href="https://www.ny-engineers.com/blog/fundamentals-of-curtain-wall-systems"> are incredibly flexible</a>, allowing for complex and uniquely shaped structures. There have been buildings emerging in the recent past in all kinds of shapes such as round, oval, triangular, wavy, and who knows what else is next.</p> <p>Transparent glass is the most characteristic feature of curtain walls, but there are plenty of other options such as colored/opaque glass, metal, and stone. These materials provide a wide variety of colors, textures, and finishes for that captivating look. The panels allow for unusual shapes such as angles or curves.</p> <h3>Structural Stability</h3> <p>The fragile look of the glass façade should not deceive you; curtain walls offer the necessary agility withstanding external forces such as high winds.</p> <p>The walls reduce sway by transferring the kinetic energy to the main structure. The panels, spanning multiple floors, are designed with a space between them accommodating thermal expansion and contraction.</p> <p><a href="https://www.wbdg.org/guides-specifications/building-envelope-design-guide/fenestration-systems/curtain-walls">Curtain walls also prevent water penetration</a> and the consequent damages associated with water retention. This benefit enhances the durability of the structure and reduces maintenance costs.</p> <h3>Fire Resistance</h3> <p><img src="/Portals/0/Images/Fire%20with%20Curtain%20Wall%20System.jpg?ver=2020-04-14-115704-317" alt="Fire with curtain wall system" longdesc="Fire with curtain wall system" style="border: 1px solid #000000; float: left; margin: 12px;" />In case of fire, curtain walls inhibit the spread of fire from one floor to another. In some cases, the glass acts as a barrier. The glass slows or sometimes prevents the fire from spreading across the surface of the building. This ability is a massive benefit in tall buildings where fire otherwise rapidly spreads upwards, increasing the danger and damage.</p> <p>For many years, polished wired glass was the only type of glass passing <a href="https://www.nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-standards/detail?code=80">NFPA 80</a>. Appearances were deceiving; although the glass looked secure, the wiring only held the glass in place in case of a fire. Ordinary glass shatters when heated over 250 ºF. That shattering glass creates a grenade-like effect, expelling the wire-like shrapnel, causing significant injuries.</p> <p>Increasing injuries and the desire for a modern-looking, fire-rated curtain wall was the impetus behind the research for new solutions. One such solution led to the development of impact safety glass that blocks heat.</p> <p>Framing materials have also grown to become fire-resistive, too, by using roll-formed steel using thin gauge steel coils. This <a href="https://www.iccsafe.org/building-safety-journal/bsj-technical/the-system-solution-fire-rated-glazing-systems-in-modern-design/">method produces narrower frames</a> than traditional hollow metal steel frames.</p> <blockquote> <div>A supplementary benefit of these next-generation fire-rated steel curtain wall systems is their ability to achieve nearly any finished look. The steel profiles can be powder coated at the factory, while the exterior cover caps can be manufactured from aluminum or stainless steel and then finish matched. If the cover cap is aluminum, it can be painted or anodized. The shape of the cover cap can also be customized; however, this necessitates early involvement with the manufacturer or supplier to ensure all project needs can be met.</div> </blockquote> <p><strong><br /> </strong>These are just some advantages that continue propelling curtain walls to the top of the list of options for commercial buildings. This system is also cheaper when compared to other wall options.</p> <h2>Types of Curtain Wall Systems</h2> <p>There are two <a href="https://facadenvelope.com/what-are-curtain-walls/">types of curtain wall systems</a>, depending on the method used to assemble the components. There is a third type, although less common, that borrows from the characteristics of the two.</p> <h3>Unitized System</h3> <p>Component assembly occurs in the factory. Afterward, the assembled components are transported to the construction site. The size of the unit depends on the distance between one floor and the other. High-rise buildings typically use unitized systems. Since components arrive preassembled, the installation process is more straightforward and requires minimal equipment. A temporary hoist or a mini-crane is generally adequate for installation.</p> <h3>Ladder System</h3> <p>The ladder system has a lot of similarities with the stick-built system. Some components of the curtain wall are prefabricated in a factory while others on the installation site. In most cases, the factory assembles the frames before transporting them to the site. After installing the frames to the building, installing the glass comes next.</p> <p>This method borrows features from the unitized and stick-built systems.</p> <h3>Stick-Built System</h3> <p>Here the different components of the curtain walls <a href="https://www.glassmagazine.com/article/curtain-wall-fundamentals">are fixed piece-by-piece</a> onto the structure of the building. Low-rise buildings typically use this system. The sticks refer to the aluminum frames set between floors, both vertically and horizontally. Cranes and scaffolding provide external support during installation.</p> <p>The installation process takes more time than the former, but allows for adjustments as necessary, unlike a complete unit.</p> <h2>How are Curtain Wall Systems Built? </h2> <p><img src="/Portals/0/Images/curtain%20wall%20drawing.png?ver=2020-04-14-151433-010" alt="Basic components of a curtain wall" longdesc="Basic components of a curtain wall" style="width: 450px; height: 459px; float: right; margin: 12px;" />The construction of a curtain wall <a href="https://facilityexecutive.com/2017/03/the-basics-of-curtain-wall-construction/">consists of two main components</a>: the frame and the glass.</p> <p>The frame is typically aluminum and, in some cases, steel. Aluminum is the first choice because it's light. <span style="font-size: 17px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: 0px; font-family: ProximaNova-Regular;">Different types of glass can be used, such as annealed glass, tempered glass, laminated glass, and so on. </span><span style="font-size: 17px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: 0px; font-family: ProximaNova-Regular;">The assembly of these components takes place in the factory or on the installation site.</span></p> <p>Factory assembly saves on installation time and labor. Assembling on-site requires more time and equipment, but allows for adjustments if necessary. In some cases, manufacturers substitute glass with metal panels or thin stone, although glass remains the most common.</p> <h3>Structural Glazing vs. Curtain Walls</h3> <p>Another phrase commonly heard is structurally glazed. The glass is bonded to the curtain wall framing using <a href="https://news.3m.com/es/press-release/company/3m-vhb-tape-makes-its-us-debut-exterior-curtain-wall-glazing">Very High Bond (VHB) tape</a> along the edge of the daylight opening then caulking the rest of the area using silicone. (Image to come)</p> <p>Here, the glass is integral to the construction design and carries some weight in the structure, unlike curtain wall systems, which only bear their weight.</p> <p>While curtain walls cover the entire building exterior, <a href="https://www.wwglass.com/blog/post/what-is-structural-glazing/">structural glazing</a> consists of large glass panels installed alongside other building materials such as stone.</p> <p>Either way, a glass exterior bears a host of benefits and continues to be a predominant feature in future structures.</p> <h2><strong>In Sum</strong></h2> <p>The prominence of curtain wall systems has been on a steady upward trajectory. This trend is likely to continue. Increased environmental awareness, coupled with stringent government regulations, have increased the demand for green buildings, and curtain wall designs have a lot to offer.</p> <p>Then there is the most appealing feature of all - the design flexibility allowing for the construction of uniquely-shaped buildings, unlike anything we've seen before. There's no doubt that curtain wall systems will continue to grow exponentially for years to come.</p> <p>Nowadays, when I'm in a waiting room, I look out the window with regret because the bad guys avoided their inevitable fate. </p> <p>After all, there's no X for me to use to find them.</p>23A Surprisingly Vexing Question: What Makes Architectural Embeds Vital?https://www.schuettemetals.com/blog/postid/41/what-are-architectural-embedsEmbedsTue, 10 Sep 2019 19:08:00 GMT<p style="text-align: center;"><img alt="A Surprisingly Vexing Question: What Makes Architectural Embeds Vital?" src="/Portals/0/LiveBlog/blog/What-Makes-Architectural-Embeds-Vital.jpg?ver=f4uaR5PRI2P1IOFEbKn5fg%3d%3d" style="margin: 5px; width: 800px; height: 425px;" /></p> <p>We see the result of their jobs every day, but only if we're looking.</p> <p>They're something taken for granted, but for years, their job was an open riddle, hoping to be solved.</p> <p><img alt="An Illustration of an Architectural Embed" src="/Portals/0/Images/Embed.png?ver=2019-09-10-072047-747" style="float: right; margin: 5px;" />What are they? <strong>Embeds</strong>.</p> <h2>What are Embeds?</h2> <p>Considered the best method, embeds attach concrete to steel framework.</p> <p>The plates, prefabricated steel with lugs welded to them, are cast inside concrete. Lugs attached to concrete reinforcements held the embed in place. The exposed plate creates the surface connecting steel to concrete.</p> <p>Hot-rolled steel sections, used in construction, <a href="https://www.usglassmag.com/fieldnotes/anchored-in-reality-getting-anchors-and-embeds-right/" target="_blank" title="New Window">changed the various designs</a> for embeds and anchors. These sections provide changes creating higher tolerances when placing the embeds.</p> <h2>An Important Piece of the Puzzle</h2> <p>Because their delivery is so far in advance, time becomes tight when making sure everything is correct. If there are no complications, the embed process makes the project go much smoother. If not, then your project falls behind because of the time inefficiencies.</p> <p>Embeds play a large part in a sound anchor system. As such, there's a lot involved when engineering embeds for a project. Specifically, the following are essential considerations when designing embeds:</p> <ul style="margin-left: 80px;"> <li>How much of a load imposed on the embed?</li> <li>The strength of the concrete resisting that load</li> <li>The embed design</li> <li>Building materials</li> <li>Labor costs</li> </ul> <p>Connecting embeds to footings or walls occurs in several ways;</p> <ul style="margin-left: 80px;"> <li>Precast columns</li> <li>Beams</li> <li>Plant</li> <li>Double tees</li> <li>Slabs</li> <li>Wall panels</li> </ul> <p>Technically, embeds aren't individual components. Instead, they're an important piece of the structural system. How embeds became a critical aspect of construction isn't exactly clear, but their roots reach back over 160 years ago.</p> <ul style="margin-left: 80px;"> <li>1848: <a href="https://www.maisonlambot.com/en/joseph-louis-lambot/" target="_blank" title="Jean-Louis Lambot">Jean-Louis Lambot</a> first used reinforced concrete when building a boat using iron bars and mesh.</li> <li>1854: A Brit, <a href="http://madeupinbritain.uk/Reinforced_Concrete" target="_blank" title="William B. Wilkinson">William B. Wilkinson</a>, made the first building using reinforced concrete of a two-story cottage he built for his servants.</li> <li>1853: Frenchman <a href="https://www.amusingplanet.com/2019/06/francois-coignets-reinforced-concrete.html" target="_blank" title="François Coignet - New Window">François Coignet</a> first used iron reinforced concrete on a widespread scale.</li> </ul> <p>In his 1959 book, Concrete, Peter Collins <a href="https://architecturefarm.wordpress.com/2014/06/07/coignet/" target="new">considered Coignet</a> as an unsung hero of the modern world.</p> <blockquote>"Coignet can justly be regarded as the man who first brought mass concrete construction to the knowledge of the modern world, and who in his lifetime exploited it to its utmost capacity. His methods were far more scientific than those practiced elsewhere in his day, and although he never undertook laboratory experiments, or attempted to ascertain theoretically the economic dimensions of the material required, he spared no pains in making practical tests."</blockquote> <p>BN Products created the <a href="http://www.bnproducts.com/blog/the-history-of-reinforced-concrete/" target="_blank" title="History of Reinforced Concrete">following timeline</a> showing the history of reinforced concrete. Despite the long history of concrete, the idea of reinforcing it didn't occur until the mid-19th Century.</p> <p style="text-align: center;"><a href="http://www.bnproducts.com/wp-content/uploads/2014/02/BN_Infographic_Reinforced_Concrete.png" target="_blank"><img alt="History Timeline for Reinforced Concrete" src="/Portals/0/Images/reinforced%20concrete%20timeline.jpg?ver=2019-09-09-135010-487" style="text-align: center;" /></a></p> <p>Embeds started appearing in construction projects in Boston, Philadelphia, and New York in the 1920s. Their job was simple, provide conduits for cables and wires.</p> <p>The first conduits were steel, embedded in poured concrete floors with access points for various locations. Once placed, the last step connecting electrical wiring was feeding cables through the tube.</p> <p>As time passed, embeds provided an attached surface of restraints and supports for electrical raceways and equipment. Before embeds, finding locations for the walls and floors <a href="https://www-pub.iaea.org/MTCD/Publications/PDF/P1526_Web.pdf" target="new">relied on on-site measurements</a>.</p> <blockquote>"… In previous methods of construction, tape measures, levels, etc. were used to locate the position of the walls and floors to be constructed, and subsequently the equipment, piping, electrical raceways, HVAC; etc. Each of these assembly operations was performed using the stick-build construction method, with thousands of single-component fitting tasks occurring simultaneously in the same physical floor space at various distances above the floor. This meant that mazes of scaffolding were required to access locations above the floor, resulting in a progressively decreasing workspace in which to perform the tasks."</blockquote> <h2>Exploring Other Types of Embeds</h2> <h3>Curtain Walls</h3> <p>A <a href="https://www.schuettemetals.com/blog/the-concealed-safety-of-curtain-walls" target="_blank"><strong>curtain wall system</strong></a> is a non-structural external wall that comprises wall panels attached to the outside of the building's floor slabs; in plain terms, they hang on the structure like a curtain. Installers usually use curtain walls on large, high-rise commercial buildings. Unlike other exterior walls that make up an essential component of the structure, curtain walls only support themselves. External forces are transferred to the primary structure through columns or floors because curtain walls bear only their weight.</p> <p>Not only do curtain walls help with the building's aesthetics, they also help <a href="https://www.schuettemetals.com/blog/how-curtain-wall-systems-help-prevent-catastrophes" target="_blank"><strong>contain fires</strong></a> for an unspecified amount of time, hopefully providing enough time for people to escape the danger.</p> <h2>In Sum</h2> <p>The history behind reinforced concrete and embeds is a bit complicated, but it all revolves around the use of steel sections through the ages.</p> <p>In the 19th century, blacksmiths used iron for reinforcing structures. They embedded the iron in a concrete mix that gave the structure strength. As buildings became taller, the problem became getting iron into the structure, creating an evolution towards using steel.</p> <p>Steel is much easier to work with than iron, yet it still provides the same strength. The un-reinforced concrete (or "un-reinforced masonry") was out of sight from the eye. However, this wasn't the end of the story. Steel alone isn't as strong as concrete. That's where embeds come into play.</p> <p>Embeds add reinforcement and strength to the structure by holding the steel in place and providing an attached surface for other reinforcements. Using steel embeds also adds flexibility. It's possible to change designs, add connections, and move them. They're also built with a lot of room for error.</p> <p>That's good because few people like surprises. Embedded technology is only beginning, so there are more questions than answers. Future research may show that the best designs are the ones that spend the most time developing, testing, and evaluating.</p> <p> </p> 41