Mechanical joints: trade’s role in improving the face of PVCU

Clare Higgins, product manager at Rehau, discusses how the trade needs to give a wider appreciation of the use of mechanical joints in PVCU and how it benefits both the fabricator and consumer.

It’s clear that PVCU flush fit windows are becoming increasingly popular alternatives to their timber counterparts; with the ability to create a realistic timber-look frame, that can be matched with the style of the building, there is a higher demand for fabricators to provide high quality PVCU windows as an alternative to timber to cut down the end-users’ overall costs.

Despite the increased demand for a cost-effective alternative, consumers still expect a high-quality product, right down to the finer details. For example, they will even be assessing how the sash is jointed, to ensure they have the perfect window to match their property. Therefore, fabricators need to consider the best jointing solutions for individual projects.

The method used to fabricate the joints in a window is important in regards to how well it will perform in the long run. Tightly sealed joints will provide adequate protection from the elements, such as wind and rain, ensuring good insulation for the property.

The manufacturing and installation methods of timber frames go hand in hand with traditional window joinery techniques. Because of this, many older timber window systems, installed before PVCU arrived in the window market, tend to have the traditional mechanical joints in place. This type of joint gives the window a distinctive look that is recognised as a traditional timber-frame window and fabricators who can replicate this look with PVCU will reap the benefits with increased sales.

Reports have shown that the majority of fabricators choose to weld their flush sashes, which is cost-effective in the short term, but creates a less authentic-looking timber alternative. As PVCU gained more popularity in the market, the traditional mechanical joints were considered a costly and time-consuming method, which resulted in fabricators opting for alternative ways of jointing, such as welding the mullions and transoms together. A welding joint is considered much easier to manufacture and it costs less to produce, but it will not exactly replicate its timber alternative.

As well as creating a strong, durable window, the mechanical joint option fully enhances the window for ultimate authenticity. The jointing option chosen for the window is crucial to the overall look of the finished product and windows such as Rehau’s Rio Flush Fit allow fabricators to offer a product that fits with any aesthetic for very little additional installation work, using either mechanical joint blocks or a MechWeld joint solution.

Many well-established window companies offer products that work with both mechanical and welded joints, giving fabricators full flexibility over their choice of window joints in order to meet the needs of the project. The MechWeld joint, for example, offers the appearance of mechanical-style timber joints on the outside with a fully welded detail inside. Modern PVCU window systems such as the Rio Flush Fit allow fabricators to replicate the finer details of a traditional timber flush fit window through a range of jointing solutions to suit different styles of properties.

To achieve a true likeness to timber frame windows, we must consider investing time into using a mechanical joint within their manufacturing process. PVCU technology has evolved phenomenally and, through careful consideration of the finer details such as jointing options, can be a true leader as a cost-effective timber window alternative.

To truly take advantage of the benefits of PVCU, fabricators need to look towards a combination of using mechanical joints alongside welded joints in PVCU flush sash windows. Not only does it provide a cost-effective but durable solution, but it gives consumers an aesthetically pleasing product that is suitable for a wide variety of building projects.