ᐅ Insulation of Gaps Around Window Shutter Boxes – Renovation of Older Buildings

Good morning everyone,

In our house, the windows including the roller shutter boxes have been replaced. We are currently unsure about the sealing and insulation of the joints between the window frame/roller shutter box and the corresponding wall.

A special feature in our case: since there is a slant in the outer wall area near the lintel for some windows, the windows and roller shutter boxes had to be recessed a few centimeters (centimeters) inward (window offset).

Inside, most windows (but not all ...) have a vapor barrier installed in the window area. The roller shutter box area does not have a vapor barrier. Is this common?

The joint between the window frame/roller shutter box and the wall was filled with expanding foam for these windows (photo: windowsill area), and the reveals were sealed with sealing tape where possible, always with foam at the bottom. However, there are several areas where the foam is not continuous, and for some windows, foam is no longer visible past halfway (no sealing tape either), and in some corners you can easily push a wire through these areas to the inside.

At the lintel area, the joints between the roller shutter boxes are so large (several centimeters (centimeters)) that you can partially see outside. The area marked "window offset" in the photo is an example. The interior installer has already plastered the joints from the inside. So, the only option left is to take action from the outside.

According to the window installer, the newly created joints should only be closed with exterior render. That would, of course, close it at first. We are now worried that this will lead to poor insulation and sealing because only the render would act as a barrier to the interior in some places.

As a layperson, it seems strange to me that the areas between the window frame/roller shutter box and masonry have gaps. What good are high-quality windows if the joint is a potential weak point?

One more question: how critical is UV exposure to the foam? According to the datasheets, the foam should be protected from UV light. In our case, it has already been exposed to light for 3 months.

Thank you very much and have a nice Sunday.

This looks like poor workmanship. Even with a wire, you must not run it from outside to inside or vice versa.

Do not just close it up; have an expert inspect it and demand the correction of any identified defects...

Thank you for the quick response.
So our understanding is correct after all, that once the windows are installed (even without interior and exterior plaster), there should be no openings in the joints allowing passage from the outside to the inside.

Good evening,

Is there any updated assessment regarding PU foam and UV radiation or any other evaluation of the matter?

Thank you!