In 2010, we were asked to overhaul our skylights installed on an industrial building 16 years before and carry out the necessary refurbishment. Only 4 out of 10 skylights we installed in 1994 needed overhauling in spite of the fact that the warranty expired 13 years earlier! The skylights in question measured 205 cm in width and 360 cm in length each. The material used for their construction was one-layer opaque polycarbonate of 10 mm in thickness. The owner of the building showed us the approximate location of leaks and asked us to find them and fix them.
The defects we spotted on the outer side of the skylights were as follows
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We found two holes of around 9 mm in diameter on the surface of the polycarbonate sheets. We did not, however, observe any defects on the interior side of the pc sheets, so the holes could not have been the source of leaks because the rainwater which got into the inner layer of the polycarbonate flowed down the cells into the skylight drain system and then down the rooftop. The defect we spotted, then, was either caused by a sharp tool or a falling object on the outer side of the pc sheet.
Examination of the metal skylight base
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We found wet stains at the conjunction of two metal elements, which meant we localized the exact place of the leak. There was water coming out on the rooftop when we tried to press the metal elements towards the roof cladding.
Examination of gaskets and polycarbonate sheets
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The EPDM gaskets we used 16 years before were in good condition. The additional protection for polycarbonate cells in the form of self-adhesive aluminum foil (which was commonly used a few years ago) proved unexpectedly efficacious. The PC sheets bore little traces of impurity and the foil stuck so hard that it was difficult to remove it.
Examination of the screws
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There were no traces of corrosion on the screws, only some traces of surface oxidation.
Conclusions
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Judging from our experience, we are free to say that solid or cellular polycarbonate which is correctly installed within the system of our aluminum profiles can withstand long years of exploitation even in heavy weather conditions. It is important to remember, however, not to expose the polycarbonate to chemical substances and mechanical defects and to overhaul the entire installation at least every 7 years.
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The aluminum frame constructed entirely from specially designed profiles was in a very good condition. The skylight refurbishment involved only the exchange of a few screws, gaskets and sheets. It must be mentioned that the polycarbonate sheets in our skylights can be easily replaced without the necessity of changing the aluminum construction.
