Case story: Composite doorstep for lifting-sliding doors

Case story: Composite doorstep for lifting-sliding doors

Composite doorstep for lifting-sliding doors minimizes thermal bridging

GRP composite is set to eliminate conventional doorstep materials. The MACO Group of Salzburg, Austria, has included composite doorsteps in its programme of lifting-sliding doors since 2005. The structural benefits have been realized in full and sales have exceeded all expectations.
Lifting-sliding doors make tough demands, particularly to the dimensional stability and thermal expansion of their constituent materials, and increasingly also to the tightness and thermal insulation of the doorframe and glass. And doorsteps must naturally be easy to install.

As they are characterized by several properties not normally found together in conventional materials, composites were sooner or later bound to attract the attention of doorstep manufacturers. This was also the case with MACO, which “discovered” composites after testing and rejecting a wide range of alternatives, including various combinations of materials. In 2004, after a tip from an Austrian manufacturer of extrusion tools, MACO contacted Fiberline Composites, the European specialist in GRP pultrusion profiles.

MACO’s performance specifications and Fiberline’s GRP know-how led to the development of a doorstep profile that must be considered unique. Compared to MACO’s existing aluminium profile with thermal separation, the advantages of the GRP profile were - and are - so convincing that any original trepidation and doubt on the part of customers was rapidly overcome.
Since market launch in 2005, sales of the company’s GRP doorstep have rocketed and now total 15,000 metres annually. Sales continue to rise. Rene Baumgartner, the company’s head of patents and standards, has no doubt that this is only the start and that MACO’s product programme will gradually switch entirely to GRP.

“The advantages of GRP composite are so convincing that it will eventually capture the whole market. It is quite simply the optimal solution,” says Rene Baumgartner.

The key advantages of the new doorstep are:

• Thermal separation is unnecessary
• Effective insulation against heat and cold
• No thermal bridging, draught or condensation problems
• Insulation can be further enhanced by foam injection
• Tightness
• High dimensional stability
• Resistant to very high and low temperatures, incl. frost
• Simple structure makes cutting and installation easy
• Available in all colours
• Hardwearing surface
• Fits up to three sliding panels/sliding units
• Doors slide quietly and easily
• Ease of opening
• Wheelchair-friendly - step height just 17 mm

Using accessories the doorstep can be widened to 308 mm, making it suitable for large doorways as well as low-energy buildings and passive houses.

Supplied in plain finish or grey-lacquered (high durability and adhesion). Easily lacquered/painted by the customer in the colour required.

GRP composite has a number of advantages over conventional materials, including weatherproofing and chemical resistance (will neither rust nor rot), as well as electrical and thermal insulation properties.