Ormonde Joinery Products, which sources high quality joinery, largely for expensive homes in the Surrey stockbroker belt, has achieved a significant advance in the design of double-glazed casement windows.
Instead of timber, it has used exterior-quality Medite MDF for the glazing bars, and, it claims, created a cost-effective, quality product with great design possibilities.
Durability and performance are not in question. Ormonde supplied hundreds of these windows, largely for conservatories, at an executive estate in Virginia Water, more than five years ago. Because of the novel nature of the window design, it has maintained close contact with the development and has uncovered no problems.
It was an English Heritage site – at a former Victorian hospital, built in a resplendent Gothic style – so the developers were also required to provide sympathetic designs for both housing and apartments.
Patrick Whelan, a former builder who is managing director of Ormonde Joinery Products, was concerned about the problems sometimes associated with normal glazing bars used for double-glazed casement windows. These, of course, need to be cut separately and precisely, and then fitted, usually by hand, just as accurately. Gaps in any joint can mean water ingress and possible degradation.
Faced with the challenge of having to provide an intricate Gothic design of glazing bars, Patrick Whelan turned to Willamette Europe‘s Medite Exterior MDF.
Ormonde’s solution was to have the shape of each complete set of glazing bars cut from sheets of 15mm thick Medite Exterior. These were then applied, in the conventional manner, using a special adhesive fixture, to the inner and outer surfaces of each window. A primer and basecoat were applied to the MDF cut-out in the factory and two more coats were added on site.
Despite the wastage of MDF, Ormonde says that the overall cost was lower than using standard glazing bars. Apart from materials costs, the use of Medite Exterior cut application times, removing the need for filling and sealing as there were no longer joints with potential to cause problems later.
Cutting out the required design, including chamfered edges of the glazing bars, was achieved on a CNC router. Medite Exterior machined smoothly, with no suggestion of any breakout on the edges, not even of the most complex design.
According to manufacturer, Willamette, Medite Exterior MDF opens up a new design route for joinery producers and specifiers. Ormonde’s application of the material indicates that virtually any design of glazing bars could be achieved for double-glazed windows.
