When buying bi-folding doors the little details matter!

A major trend over the last 5 years has been the inclusion of double glazed bi-folding and sliding doors into new build homes, extensions and refurbishment projects. This is somewhat surprising given the unpredictability of the British weather, but thousands of property owners nevertheless have decided they want the option to be able to totally open up a room for example to their living room, conservatory or in most cases to their outdoor space.

The increase in volume in bi-folding doors sales has been a real growth area for the double glazing industry, with many folding and sliding door products on offer, including aluminium, PVCu and hardwood timber double glazed doors. Within each of the material types the quality of doors varies tremendously, and unfortunately there are plenty of horror stories where home owners have fitted products only because they were the cheapest, only to find down the line they are not fit for purpose. Sadly, for those wanting long lasting, trouble free, thermally efficient, well fitted bi-folding doors, these are not inexpensive products, as with high quality replacement doors of this nature, you very much tend to get what you pay for.

For example, PVCu doors are made of unplasticized polyvinyl chloride, so they clearly cannot be as robust and secure as metal doors. Also being plastic, PVCu or UPVC folding and sliding doors tend to flex, which is not ideal for a bi-folding door system that really needs to rigid and not move out of alignment. Timber hardwood sliding doors look lovely, but unlike aluminium and PVCu/UPVC double glazed doors are not maintenance free from a decorating point of view, but are usually the most expensive option to boot!

High quality powder coated aluminium bi-folding and sliding double glazed doors are expensive, but well worth the investment as they deliver excellent thermal efficiency, high security, low maintenance, plus can be manufactured in any RAL colour, with an option for dual colour (i.e. a different frame colour inside and out) and even real timber woodgrain effect. In addition, being metal, aluminium can cover greater spans and heights than other bi-folding door systems, plus aluminium is a 100% recyclable material, so very green.

High Wycombe MP Steve Baker in his Orangery Extension Built by Hazlemere Window Company
High Wycombe MP Steve Baker demonstrating his aluminium bi-folding doors on his HWC Orangery

Each systems manufacturer’s products has pluses and minuses, but it is the little details that matter when drawing up refurbishment or new build plans for your property. Take the Sapa Dualfold aluminium sliding door system. If you choose to have all the doors opening inwards with a standard threshold, the weather rating is 150 Pascals. If however, like most home owners you decide to have all the doors opening outwards, this aluminium double glazed sliding door system has a 600 Pascals weather rating with a standard threshold. If you opt for the low threshold option, the Pascal rating can go as low as 50, so it is advisable when fitting replacement bi-folding doors to exposed external elevations to choose the standard threshold option.

Getting the right configuration for your aperture is very important. Every folding doors system be it aluminium, PVCu or timber has maximum and minimum sizes that it can achieve. Remember that more folds mean more cost, more uprights, narrower overall opening, less glass and less light. As aluminium can operate at greater heights and widths (being a strong but lightweight metal) than other weaker materials, it enables property owners to have less uprights, so more double glazing and better views. Do note that doors that operate in pairs (i.e. 2, 4 & 6 section bi-folds) cannot have a “travel door”, as to open them a minimum of 2 sections have to move at same time in order for the doors to be operate. The big advantage of a 3, 5 or 7 section folding door that all slide in one direction,  is that these configurations guarantee you one section as a travel door. It is possible to get 4 and 6 section doors with a travel door, where one door (in the case of 4 section) is side hinged at one end and 3 sections slide the other way, and in the case of 6 section folding doors, have 3 sliding one way and 3 sliding the other. Both these configurations also deliver an effective set of French doors, so you get three different door operations in one, hence why getting the right configuration is important when buying replacement bi-folding doors or planning to put them into a new build house or extension.


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