Clearview National July 2016 - Issue 176 - Page 42

DOORS&WINDOWS A big mistake many window fabricators make – not paying attention to glazing packing »»ROTO EXPLAINS HOW CHOOSING quality packer products and fitting them correctly makes an enormous difference to window performance and longevity… A BIG PROMISE Imagine someone told you they could help you to increase the security of your windows and doors, avoid callbacks from customers and extend the lifetime of your products, and that you could do this with some little bits of plastic. Sounds a bold claim, doesn’t it? The thing is, that could actually be true, provided they were talking about premium quality glazing packers. CONSTANT READJUSTMENT – WHY? How is it that windows or doors, made from all the best materials, can still have problems such as sash drop, and require constant readjustment? The fact is, even when you source the very best profiles, glass units and, of course, hardware, the way you put it all together will make a huge difference to the lifetime and reliability of the finished unit. One of the most important aspects of all is the way the sash is glazed and packed. A SERIOUS ERROR In Roto’s experience, failing to ensure windows and doors are glazed correctly is one of the biggest mistakes fabricators can make. An investment in time and training in this area can save a lot of time and money further down the line. It’s an aspect of production where even fairly quality-conscious manufacturers can sometimes fall down. With the average size of windows increasing, bigger glass units are being installed. Proper packing of glazing is becoming more important than ever. WHAT ARE THE VITAL THINGS YOU NEED TO CHECK? • Check for squareness As with any job, preparation is key. You need to make sure you’re working with a frame that is correctly fixed and square. There’s a sure fire way to check a frame is completely square and it works on ones that are rectangular too. Just get a tape and measure the distance between two diagonally-opposing corners. Then, measure between the other two corners. If these two diagonal measurements are the same, your frame is square and true. If the frame is out of square, you’ll never be able to hang the sash correctly. That’s why it’s important to get this right. You can then move on to the sash. • Toe and heeling When you come to glaze the sash, it’s important to be aware of why you’re doing it. On any window, or door containing glazed units, the glass isn’t just there for people to look through: it’s a key structural element. Think of one of those wooden doors or gates that has a diagonal brace across it. Without that brace, the whole thing would quickly fall out of square and begin to drop. The glass plays exactly the same role in your window or door. Or at least, it ought to. When you toe and heel, you’re not just trying to support the glass and hold it in the right place. You should be aiming to brace the sash and form a rigid structure. Only then will you be able to avoid it deforming later on. Glazing should be packed on all sides in order to protect the edges of the unit from damage. It should certainly never rest on the inside of the sash. THE RIGHT PACKERS The packers you use should be of the correct size so they support the glazed unit across its full width and spread the load evenly. Of course, that will vary depending on whether you are using double or, as is becoming more common, triple glazing. The packers need to be strong: nowadays you could be talking about sashes weighing 200, 300 or even 400 kg in the case of Lift & Slide doors, for example. You can’t afford to have packers that crush or deform, and you need a selection with a wide range of different thicknesses to choose from. This will enable you to get the bracing absolutely right. PACKING HELPS SECURITY TOO Toe and heeling isn’t the only reason for using packers. You should also insert them at strategic positions to support locking points and hinges. This will make the sash harder to manipulate. It increases protection for your customers, and of course also helps your product when it gets exposed to the manual attack elements of the BS and EN security standards. product-view/detail/roto-glas-tec/-/ 42 » JUL 2016 » CL EARVI E W- UK . C O M