Materials | What to look for when choosing bifold doors
When IDSystems was founded nearly 20 years ago the choice between bifold door products available was very small indeed, indeed it took a number of years before 'bifold door' even became a term. However in the last ten years the number of systems on the market has exploded and there is more choice than ever before.
Whilst choice for customers is a good thing, it makes understanding the differences between doors and finding the right system for your own project more challenging. To help you choose we've put together some hints and tips to help you choose your bifold doors, with this feature focusing on the materials the doors are made from.
There are four choices of materials, uPVC, aluminium, timber and composite (a combination of aluminium and timber).
uPVC doors are usually the cheapest systems on the market, however given the flexible nature of plastic compared to timber and aluminium they tend to have bulkier frames and therefore less glass in your doors. uPVC also expands and contracts more in temperature extremes which may impact on the weather and thermal performance of the system as a whole.
aluminium bifold doors (and windows) include a thermal break between the outer and inner aluminium frames, preventing cold bridging from outside to inside. Not all thermally broken aluminium doors are the same, indeed the performance of system varies dramatically, so understanding how big the gap between inner and outer frames is, what the thermal break is manufactured from and how it is designed is crucial.
For reference the SUNFLEX range of aluminium bifold doors includes a patented polyamide thermal break that is made up of multiple chambers to significantly reduce heat transfer. On the award-winning SF55 system this thermal break is 24mm wide and on the ultra-thermally efficient SF75 doors the break is 44mm wide.
Timber offers a softer, natural look and is popular for more traditional style properties. Like all timber products used externally they will require either repainting or staining when necessary as part of regular maintenance. Timber bifold doors also traditionally have wider sight lines so it is worth checking the size of the frame of the system you are interested in. It is also worth checking the composition of the timber doors, some systems use a single piece of solid timber for each element of the frame, however because it is a natural material this can leave the doors more susceptible to flexing and warping.
Engineered timber, which involves multiple layers of wood being glued together with alternate grains, increases the strength (by more than 50% compared to solid timber) and means the frames can be narrower and lighter. It also increases the stability of the doors which is particularly important given the movement involved in opening and closing bifold systems. The SUNFLEX SF75h has the slimmest sight lines of any timber bifold door on the marker and is manufactured from engineered timber and is available in Meranti, Nordic Pine, American White Oak, Larch or Douglas Fir with an almost infinite choice of stains and paint colour options.
Composite doors offer a fourth option and for many the perfect combination of hard-wearing, maintenance free aluminium on the outer frame of the doors and the natural beauty of timber on the inner surface. This is achieved by either attaching external aluminium cladding to a timber framed door or by attaching a thin layer of timber cladding to the inside an aluminium frame. The SUNFLEX SF55c and SF75c composite bifold doors are manufactured using the latter technique, the lightweight nature of the aluminium door compared to the equivalent timber door means the frames can be narrower and lighter.