Dark PVC window warped - how much is permissible?

Hello everyone,

I had new anthracite-colored PVC windows (Fa. Aldra) installed 4 years ago.

At one window (1.70 m wide x 1.40 m high, two-leaf), on the sun/weather side, I have now accidentally noticed after the installation of an external roller shutter (by the window fitter) that the frame is concavely warped by about 12-15 mm.

Is this permissible or will the window eventually become leaky, etc.?

What experience have you gathered?

I am grateful for any advice.

Well, black or dark gray plastic surfaces behave sometimes extremely difficult under direct sunlight. Logically in summer. Therefore, I am not surprised by the warping. The window is also relatively large in dimension.

The plastic becomes soft and warps.

Since you have now installed exterior roller shutters, the problem should no longer arise so much next summer, as you will then have the shutters closed on the weather or sunny side.

My large floor-to-ceiling windows on the west side, where sunlight is present from 2:00 pm until evening, sometimes become so hot that you can no longer touch them on the frame. However, I have white frames and Schüco windows.

Also, for the roller shutters, I have aluminum slats in dark green. They also become extremely hot on the outside. However, without problems.
Those who have the cheaper plastic slats often also have problems with dark colors there.

From the report of an expert (but it's already a few years old):

"There are no standards for the warping of PVC windows. From an expert’s perspective, reference is made to the climate classes for wooden front doors, which allow a warping of 4.0 mm over a 'front door length'; for fixed glazing, the warping may be somewhat greater, but always with the restriction that airtightness, closing force, and rain resistance must be maintained.

When working in the roof and terrace areas with a liquid waterproofing, the maximum expansion values for liquid waterproofing apply, which are generally limited to 3 mm."

Are the windows correctly manufactured and installed?
- appropriate reinforcing steel
- size restrictions observed (at least in extreme dimensions)
- mounting brackets
- widening with reinforcement
etc.

As a result, in my opinion, there is a defect given the size. With the warping, the glazing unit is soon no longer covered by the frame.

P.S. Warping per side or total? Question regarding consequential damages.