General information about plastic windows

What is the benefit of a RAL quality-monitored window?

The developer/user has the assurance of knowing that the quality of all window components and manufacturing steps is subject to regular external monitoring. The aim of quality assurance is the lasting fitness for use of the window so that you can take pride in your window for decades to come.

By contrast, the CE mark only confirms the existence of certain characteristics in the as-new state.

What tests and inspections have to be carried out?

The aspects which are determining “quality” according our RAL-GZ 716 require

  1. a defined minimum content for the system description. In that description the system-giver has to describe the profile system in a comprehensive way for the window manufacturer,
  2. a minimum of six different sample windows, some of them to be built in maximum allowed size, must each undergo a defined test procedure and meet minimum performance requirements.

Depending which types of construction as well as types of opening of windows are described in the system description, the amount of sample windows to be tested may grow to up to 15 pieces. The test results obtained (like tightness or repeated opening and closing) characterize the performance of the window profile system under extreme conditions. The reports can be handed on to the window manufacturer.

The so called Technical Appendices I and II (to RAL-GZ 716) define requirements for components and procedures which will be used in the profile system carrying the RAL-q-mark. some examples:

  • Window profiles: dimensional correctness, proper processing, weathering resistance, etc.
  • Gaskets and their raw materials: sealant capability, weathering resistance, continuity of the material, etc.
  • Foils / films for lamination: weathering resistance, heat build-up, etc.
  • Adhesive systems for lamination: stability against hydrolysis, resistance against peeling, etc.
  • Lamination process: obey the defined process requirements, lamination-quality

What quality assurance is at the window?

There are 4 quality associations involved in a finished “RAL window”. Our task as the GKFP is to monitor the proper design of a window system that a system designer (the developer or manufacturer of the profiles) creates. We also oversee the initial approval and regular monitoring of the quality of the finished profiles. The approval and monitoring of seals, raw materials, bonding systems and decorative films also fall within the scope of the GKFP.

The insulating glass used in the finished window is quality assured by the Opens external link in new windowGütegemeinschaft Mehrscheiben Isolierglas. The quality of the hardware is monitored by the  Opens external link in new windowGütegemeinschaft Schlösser und Beschläge.

For the end user the window construction company is the competent partner.

What do I need to remember when buying windows?

When you buy a window with a RAL quality mark, you are always “on the safe side”. Where there are special requirements on insulating properties (low-energy house, passive house, thermal insulation), make sure that the stated U value refers to the profile you have chosen. In the case of particularly large sashes (whether height, width or surface area), look for the approval of the profile, hardware and glass manufacturer for these sizes. Talk to your window construction company.

What do I do if there are problems with a (new) window?

Your contract partner and so the person to speak to is the window construction company. The windows it has built must conform to the system description (= construction manual) that the system designer gave it. If parts specified there are replaced with non-OEM parts, evidence of their equivalence must be provided.

What about the thermal insulation properties?

Make sure that the stated U value refers to the profile you have chosen. U values can be measured or computed (according to a standard). Computation sometimes gives a poorer value than measurement on the same profile, but the advantage is that you get the computation for exactly the frame/sash combination used.

And the airtightness?

There are tests for windtightness, resistance to driving rain and much more for every window system. Airtightness is divided into classes. The appropriate class to use will also depend on the height of the building, the point of the compass, climatic conditions, and so on.

How long will a plastic window last?

Permanent fitness for use is the basic idea of our RAL quality assurance. A window will last several decades. After being opened and closed 10,000 times windows must still be perfect when it comes to the approval test.

Are both white and coloured windows non-fading? What about the decorative wooden surfaces?

One of the key parts of the approval test is resistance to weathering. Both the (white) plastic material and also any coloured surfaces and decorative wooden designs that are used are subject to weathering. The mechanical and optical properties and the adhesion of the decoration must be flawless.

What about window care?

Regular window-cleaning should be a matter of course. Avoid the use of caustic and abrasive cleaners. Care instructions will be provided when you buy the window.

What about window servicing?

Like all mechanical parts, the hardware needs to be maintained. Follow the instructions on the hardware (e.g. “Lubricate every year”) or in the documents you were given by your window manufacturer.

What happens with old plastic windows and roller shutters that have been removed?

The plastic from windows and roller shutters can be recycled (reused).  Opens external link in new windowRewindo Fenster-Recycling-Service GmbH organises recycling activities. Speak to your window construction company.