External Bifold Door Glazing

If you've made the decision to embolden your home with a set of external bifold doors, you probably already understand that, more often than not, the doors really need to be glazed in order to get the most out of them.

One of the primary reasons so many people have fallen in love with bifold doors in recent years is the amount of light they can bring into a room, and how much larger and more open they can make a space look. Without adequate glazing, these benefits are lost. 

What Type Of Glazing Is Used For Bifold Patio Doors?

Glazing is as much about style as it is about safety and security of course, but the first question you should be asking is whether you fancy double or triple glazing, because single glazing simply isn't an option anymore with modern bifold door designs.

Double glazing is obviously the more common and affordable option, with the only real negative being that, if the seal between the two panes are not tight enough, air could seep into the space between them and cause condensation inside the panes, which would require them to be removed and cleaned, and the crack sealed up to stop it from happening again.

Whilst all modern external bifold doors will be shipped with toughened safety glass as standard, double glazing is even safer, as two panes are obviously harder to break than one single pane. The space between the two panes also acts as an added layer of insulation, creating a greater thermal resistance that will keep your home warmer in the winter months and cooler in the summer.

This means less reliance on expensive heater and air conditioning units and, in kind, a smaller energy bill at the end of the year! Double glazing is not only energy efficient, of course, but has the added benefit of minimising noise.

Sealed double glazing will reduce medium and high frequencies such as the human voice, and thicker glass will obviously improve sound reduction even further. As such, you'll want to seriously consider the thickness of your glass, as well as the amount of space between the panes, which can range between 6mm and 20mm, with a minimum space of 12mm recommended for optimum thermal performance and noise reduction.

If, however, noise is a significant issue, for example, if you happen to live by air airport or train station, to achieve even greater acoustic control and reduce low frequency noise such as traffic and aircraft, the optimum air gap recommended is 150mm or over. However, please note that such large gaps will allow convection to occur between the panes, therefore reducing insulation.

Triple glazing and high performance coatings will obviously improve your homes thermal efficiency even further. It is, however, around twice the price of double glazing. Over time, you will definitely save money by installing triple glazing, as triple glazed bi fold doors generally have a U value of around 0.8, whereas double glazed doors will have a U value of between 1.2 and 1.4.

As such, triple glazing is used extensively in countries with perpetually cold climates, but, in a country such as the UK, the savings you'll be making, even in the long run, will be minor, even if we have a particularly cold year. Ultimately, the choice is yours. Double glazing your exterior bifold doors will make your home more comfortable, but triple glazing them will make it even more comfortable. It's up to you how much that comfort is worth.

In terms of design, there are numerous options available whether you decide to go for double or triple glazing. There are plenty of styles available to suit traditional homes, from simple glazed frames to those with panes subdivided into smaller panes by vertical and horizontal glazing bars, leaded lights and panelling.

Alternatively, many companies including ourselves might offer a bespoke design service, so you can have them match existing glazing in your home and end up with exactly the right glazing design for your property. This would obviously set you back a little more though.

Types Of Glass Used For External Doors

This is where things start to get a little complicated, as there are a surprising amount of options here, which offer varying degrees of insulation and security, and also offer strikingly different looks.

Toughened Safety glass – This is a given, as it's now a legal requirement that all bifold doors must have toughened or tempered safety glass as a bare minimum. Not only is this glass stronger and more thermally sound than regular glass, but when it is broken (though you'll definitely be in for a job if you want to break it) it will shatter into smaller pieces rather than large shards.

It's the same kind of glass you'll see in many modern cars, and is created using a slew of controlled chemical treatment processes. This tempering process puts the outer surfaces of the glass into compression and the inner surfaces into tension, resulting in stronger, safer glass.

Frosted glass – Whilst installing frosted glass in external bifold doors might not be as common as installing it in internal doors, such as bathroom doors where privacy is more important, it is definitely an option if you're looking for a little added privacy and don't fancy installing blinds or curtains. Frosted glass can also be etched to create patterns or even numbers, letters and logos if that's your bag.

As such, frosted glass would be a great choice for a commercial property, as your exterior bifold doors could actually be branded! For those that are interested, the frosted effect is achieved by using corrosive hydrofluoric acid, which results in the removal of some silica from the glass surface, and leaves a roughened, frosted appearance.

Textured glass – This is achieved in a similar manner to frosted glass and is a very similar effect. The difference is that textured glass can come in a variety of different textures (as the name suggests) such as rippled, beveled and water glass.

Laminated glass – Whilst it is just as strong as toughened glass, laminated glass acts very differently, as it consists of two pieces of glass separated by a layer of poly vinyl. This layer keeps the glass bonded together even when it's broken, producing a 'spider web' effect instead of breaking into shards.

Most car windshields are made from laminated glass, and with external bifold doors, they are a good choice if there is a chance of human impact. So it's great for families with small children.

External Glazed Bifold Doors: Repairs & Adjustments

Glazed bifold doors can be more difficult to repair and adjust than regular patio doors. For one thing, if it's just the glass itself that's broken, you might not need to remove the entire door mechanism, just the glass itself, which should be reasonably simple.

The glass itself might suffer due to condensation or moisture building up between the panels, or cracks might develop over time. In this case, removing the panes of glass individually and replacing them with fresh ones should be a case of simply finding where the glass slots into the frame and removing them carefully with the right tools.

This is obviously not a job for DIY newbies though, and remember, you can't simply clean these panels and put them back, you'll need to completely replace them. If the frames surrounding the glass on your exterior bifold doors are what's the problem, you might have a bigger job on your hands.

The doors themselves can be adjusted if they are wonky buy simply pulling them out of the track, aligning them properly and pushing them back in, but as long as the frame itself is faulty, you're never going to have a 100% secure setup.