Glazing options for windows
The original purpose of windows was to admit light into a building during the day. Historically these were unglazed openings in a roof rather than the windows we are familiar with today. The first windows were made with pieces of hand blown glass held together by lattice leading. Soon after, the invention of thinner and flatter plate glass led to larger squares of glass held together by wooden glazing bars.
Float glass was invented in the late 1950’s. Made from a mix of raw materials consisting primarily of sand, soda ash, limestone and dolomite which are mixed and then heated to around 1500 degrees. As it floats over a bath of liquid tin (hence the name), it forms a glass ribbon and slowly cooled down. The invention of float glass allowed for the quicker production of large, flawless glass sheets. This is low-cost, colourless glass is the starting point for what will become quality windows, glass doors and panels.
The invention of float glass spurred the development of advanced glazing. Double Glazing became the norm in the 1970s as energy efficiency, comfort and security became a higher priority to homeowners.
The Romans were the first known to use glass for windows, a technology likely to be first produced in Roman Egypt in 100 AD.
The science behind windows has come on leaps and bounds since Double Glazing became mainstream in our homes, making the glass options stronger, shatterproof, clearer and quieter. With so many options available to improve your home it is important to understand which would be best suited to your requirements.
Low E Glass – Great for all round performance and energy efficiency
Glass used in double glazing windows for thermal insulation is known as Low E or low-emissivity glass (the term referring to the surface condition that emits low levels of radiant thermal energy). Made with a microscopically thin, transparent layer (thinner than human hair), it reflects long wave infrared energy for heat. Strategically placed on the inner pane of glass with the purpose to maintain a comfortable temperature and help keep that heat indoors.
Low Iron Glass – Offers high clarity and high energy efficiency
Low Iron glass is a type of high-clarity glass made from silica and extremely low amounts of iron. Traditionally this type of glass is used for aquariums, display cases and some windows where extra clarity is desired. Using this type of glass in your home will allow more of the sun’s energy and heat into your home.
Toughened Glass – Will remain strong, secure and safe, even when broken
Often known as tempered glass this type is up to five times stronger than regular glass. Designed and toughened to shatter into small blunt pieces under pressure (making it much safer than shards of normal glass), it is often used for preparing balcony doors and windows, shower doors and displays, and doors and windows for industrial buildings.
The glass achieves its properties by heating regular glass at high temperatures (650 degrees) and then cooling very quickly. The process makes it tougher and up to 400-500% more resistant to heat and shock than regular glass. Once the glass has gone through this process it cannot be recut.
Laminated Glass – Won’t shatter even when or break, even when smashed
Laminated glass technically has the same strength as regular glass but contains a plastic interlayer between the two panes of 3mm thick glass. With the addition of this layer, the glass being thicker, offers better insulation and resistance against shock or damage. The plastic interlayer will hold the shards in place should the glass break, so there is no hole left in the window for an intruder to get through. Laminated glass is often used on doors and ground floor windows due to these properties. It is also the same type of glass you will find in car windscreens and shop fronts.
At Everest our 6.4mm (for windows) and 6.8mm (for doors) laminated security glass surpasses every security standard on glass with an extra layer of laminate for added assurance. Laminated glass offers significant performance benefits over non-laminated, it has been proven to provide a barrier in reducing unwanted noise and sound and also provides better protection against UV rays.
Acoustic Laminate – Excellent for sound reduction
Sound reduction glass is another form of laminated glass, containing a special polymer layer engineered to absorb sound waves to reduce noise pollution from entering your home. This type of glass is particularly effective for those households near busy areas such as main roads and airports.
Consisting of two or more sheets of glass bonded together with one or more acoustic interlayers acting a noise dampening centre, weakening the sound as it travels through the glass. By varying the thickness of the sheets of glass, you will find better sound insulation can be achieved. Additionally, acoustic laminated glass benefits from all the safety and security properties of standard laminated glass.
More information regarding acoustic glass can be found here.
Solar Glass – Great for keeping out the heat, especially in conservatories
Solar control glass allows sunlight to pass through panes whilst radiating and reflecting away a large degree of the sun’s heat. This type of glass is manufactured by tinting and/ or applying a metallic coating, incorporating invisible layers of special materials on the glass. Allowing the sunlight in, whilst repelling the solar heat.
Solar glass is often used in conservatory roofs, reducing the amount of heat that is able to pass into the room and therefore allowing a more comfortable, usable living space. The indoor space stays bright and much cooler than would be the case if normal glass is used.
The Latin word for window is fenestra, which can also be translated as “hole in the wall” and “opening for light”.
Easy Clean Glass – Perfect for hard to reach areas, like roofs
Self-cleaning (or easy clean) glass contains a transparent coating on the outside surface of the glass, applied during the making of the float glass. This works to break down dirt and spread water in two ways. The first stage of the cleaning process is “photo-catalytic.” At this stage the coating reacts with daylight to break down organic dirt. The second stage is “hydrophilic,” where the forming of droplets from rain water hit the glass and spreads evenly running off the pane of glass in a sheet and taking the loosened dirt with it, whilst drying quickly to prevent leaving streaks. During dry weather spells hosing or rinsing the glass will activate the self-cleaning function to ensure your windows are clean all year round, though it is advised not to apply great pressure (for example from jet washers) to avoid damaging the glass itself. This type of glass is typically used on conservatory roofs, where the windows can be difficult to reach for cleaning.
Obscure Glass – Offers privacy for bathroom windows
Obscure glass is a type that allows the light to come in but cannot be clearly seen through. It is designed as privacy glass, typically used for bathroom windows, shower doors and anywhere else you want privacy. Patterns are available in numerous patterns, including frosted, etched and coated, with different levels of privacy to suit your needs.
Decorative – Often on doors and feature windows
Decorative glass is an option if you want to enhance the character of your window and home. Manufactured in a variety of ways to give a wide choice of patterns, textures and colours, decorative glass effects can be created on double glazing window panels by silvering, tinting, acid-etching or applying ceramic paints. Many options can be thermally toughened or laminated, depending on your requirements. It can also be combined with Low E or solar insulation double glazing windows. The decorative glass looks beautiful in top hung fan lights (the top sashes of casement windows), as well as feature windows in halls and stairwells, and even in the glass panel within your front door.
As we have shown, there are many types of glass you can opt for when choosing your windows. The type in which you choose will depend on your requirements and purpose. You may choose to fit a regular Low E glass in the lower levels in your home, but then look at Acoustic glass for your bedroom, where it is important to reduce noise pollution for a good night’s sleep.
Glass never wears out, therefore it can be recycled over and over again. At Everest we always recycle your glass that has been removed from old windows.
For further information and advice, our consultants are available at a time to suit you to discuss your needs. Book a free, no obligation appointment today.
'Glazing options for windows'