PVC window FAQs
What are the advantages of a RAL quality-assured PVC window?
As a client or end-user, you can rest assured that all window components and stages of production are subject to regular external quality monitoring. Incidentally, by contrast, the CE mark merely confirms that the window complies with the EN 14351-1 product standard. More extensive information about quality assurance can be found here.
What tests have to be completed for a RAL quality mark?
The quality and test requirements of RAL-GZ 716 require
- a comprehensive system description containing all profiles and components
- the testing of multiple specimen windows, some of them made in the maximum permitted size, under extreme conditions for direct and conventional glazing.
The performance of the profile system is characterized by the test results obtained.
The Technical Annex to RAL-GZ 716 contains supplementary requirements for components and processes used in a profile system with a quality mark. These are in detail:
- the consistent quality of the formulation, weather resistance, appearance and dimensions as well as the adherence to the mechanical properties (e.g. heat shrinkage behaviour) of PVC profiles
- the sealing characteristics of seals and their materials
- the adhesion and heat build up during the lamination of decorative films
- the adhesive strength of adhesives for lamination
- process parameters and adhesive strength during the laminating process
What do I need to remember when buying windows?
When you buy a window with the RAL quality mark, you are choosing a product that meets proven quality standards. In general, when buying a window you should consider its thermal transmittance value Uw, the glazing and its resistance to burglary.
- A heat transfer coefficient (Uw-value) of around 1.0 W/(m²K) is common for new PVC windows with triple glazing.
- Depending on the building’s design and energy strategy, different glazing solutions may be appropriate for north- and south-facing façades.
- When it comes to burglary resistance, windows with resistance class RC 2 offer a good level of basic protection.
- For particularly large leaves, ensure that the profile, fittings and glass are suitable for such sizes. Please consult your window manufacturer regarding this.
Go to your window purchase checklist here (PDF)
What do I do if there are problems with a (new) PVC window?
Contact your window construction company immediately.
What about the thermal insulation properties of the window?
The thermal insulation properties are expressed with the U-value: the lower the value, the better. Ask for exact details of the window you have selected. U-values can be either measured or computed (according to the EN 10077 standard). The calculation does not necessarily give the same value as the measurement. Find out more about U-values and energy saving here.
What about the leaktightness of the PVC window?
There are tests for windtightness, resistance to driving rain and much more for every quality-assured window system. Leaktightness is divided into classes. Recommendations are set out, for example, in DIN 18055. The appropriate class to use will also depend on the height of the building, the direction it is facing, climatic conditions, and so on. If you want disabled-friendly door-height windows, this may entail compromises on leaktightness. Please consult your supplier or designer for further information.
How long will a PVC window last?
Continued suitability for use is the basic idea behind our RAL quality assurance. After being opened and closed 10,000 times, windows must still work perfectly in the approval test. A service life of 50 years or more can generally be assumed. This service life is specified in the table ‘Service lives of building components’ published by BBSR. For more on the subject of PVC windows as a sustainable construction product, click here.
Are both white and coloured windows non-fading?
An important part of the type-approval tests concerns resistance to weathering. For this purpose, the materials used on the surfaces of white or coloured PVC windows are subjected to a weathering test. After weathering, the mechanical and optical properties, as well as the adhesion of the decorative finishes, must be flawless. Please also refer to our Technical Appendix P.3.15. (available on request).
What is the correct way to clean and maintain windows?
Cleaning your windows regularly should go without saying. For the frames, use a splash of washing-up liquid in lukewarm water and a soft cloth. You should always avoid abrasive and corrosive cleaning products. Cleaners containing vinegar or lemon will also damage the smooth PVC surface. Care instructions will be provided when you buy the window and on our information sheet (PDF).
How are PVC windows serviced?
Like all mechanical parts, the fittings need regular maintenance. Follow the instructions for the fittings (e.g. “annual lubrication”) or in the documents you were given by your window manufacturer.
What happens with old PVC windows and roller shutters that have been removed?
The PVC from windows and roller shutters can be recycled. In Germany, for instance, PVC can be recycled through Rewindo GmbH, an initiative of profile manufacturers and recycling companies (www.rewindo.de). Talk to your window construction company. For more on the subject of sustainable construction products, click here.
