With sliding and bi-fold doors available in a diverse set of materials, David Knollman of Allegion UK explains why timber can leave a lasting impact on projects.
There’s a unique flexibility offered by sliding and bi-fold door applications. Whether fitting out a contemporary home or a larger recreation or exhibition space, compact doors are effective in saving space, providing more natural light and offering greater energy efficiency.
Though, as much as a sliding or bi-fold door feature may apply the finishing touch to a project, its material choice is an equally important consideration. Modern doorsets are supplied in a range of materials, finishes and variants and decision makers must navigate the unique offerings of each door profile and system to ensure their chosen hardware is practical in application. With that in mind, why does timber remain a popular choice for so many?
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Renowned for its versatility, timber is a finished wood that combines natural aesthetics with inherent durability. Over time, it has remained a popular style for both internal and external doors and is now widely recognised as the classic option for bi-fold and sliding door applications.
Aesthetically speaking, timber panels can help add style and sophistication to a project. The natural colouring of wood can soften a space and its features, or for some projects, act as a statement piece. Commonly constructed from hardwoods such as oak or walnut, or softwoods such as pine or cedar, timber panels and their accompanying hardware systems adhere to a more rustic and traditional preference, whilst simultaneously offering a level of style customisation through staining, varnish or painting.
The benefits of timber run deeper than surface level however, and it’s perhaps the functional advantages that has helped to keep this option relevant against a rise of alternative materials. Timber upholds natural insulation for example, with air pockets in its structure naturally creating a barrier between heat and cold. Whilst sliding and bi-fold doors allow for improved airflow and ventilation, thermal efficiency is later maintained when doors are closed. Equally, timber doorsets offer strong sound absorption, with internal doors helping to create quieter rooms and external doors shielding spaces from outside noise.
In comparison, aluminium and UPVC systems, whilst not inherently effective in these areas, do offer advantages in other situations. Aluminium, for example, is structurally resilient and requires less maintenance, where in some cases, timber may require preparation and upkeep to maintain its longevity, style and performance. In coastal or corrosive environments, an anodised finish may be applied to an aluminium finish for additional durability, but should it be scratched or damaged it can be difficult to repair. On the other hand, timber components can be easier to repair and may be more cost effective to replace, with modern timber treatments now designed to strengthen the durability of doors, ensuring reliable systems stand the test of time for 10 years or more.
Nature of the project
With manufacturers offering a range of sliding and bi-fold products that can suit both timber and aluminium door types, specification can often depend on project, property and mechanism position. Whilst style may be preference led, end users and specifiers are reminded of the design considerations that must be followed, such as whether a system needs to be top hung or bottom rolling.
For folding door designs, timber will often be applied when using top hung systems, with hinge pins extended up into the top rollers where required. As the centre of the track must be offset to align with the hinge pins, the frame on timber top hung systems is usually thicker, but with minimal leaf preparation necessary – particularly when non-mortice hinges are used. Comparably, whilst aluminium systems can accommodate a bottom roller housing within its panel profiles, timber variants can also be applied to bottom rolling systems but may require bespoke bottom profiles or panel corner removal to accommodate the roller system. In these instances, the track systems are usually inline and not visible from either side, allowing for a narrower frame. For sliding door designs, installation is similar and may only require minor alterations to the door, regardless of material, suggesting this choice can often be left to personal preference.
When it comes to security, there is also not much to separate material choice. Both timber and aluminium systems can utilise multipoint locking systems on the swing leaf of an odd leaf system, ensuring Product Assessment Specification (PAS 24) and Secured by Design (SBD) requirements are met. PAS 24 is a testing system applied to complete installations, including the door, frame and hardware system, whereas SBD can be awarded to hardware elements such as locks, hinges and sliding door systems, with both accreditations signifying quality assurance and security performance.
Amidst the many differences and similarities between materials, the number of bi-fold and sliding door possibilities continues to grow and decision makers are tasked with a more difficult choice than ever before. Yet, there’s a reason why timber systems have had a lasting impact on the market. In combining tradition and elegance with contemporary customisation, timber has proven its unique qualities for decades – it’s what makes timber timeless.