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AndreasPlü17 Aug 2018 07:59Hello,
we have chosen a rooftop photovoltaic system for our roof, which was recently installed.
Now I am wondering how the hole created by the photovoltaic cables in the roof should be properly sealed. It has a diameter of about 3 cm (1.2 inches). Since the electrician who will complete the final work has not arrived yet, I would like to learn a bit more in advance than I currently know (which is nothing so far).
The roof structure (the house was built according to the 2016 energy-saving regulation standard and is very airtight according to an air tightness test, value 0.59):
- Concrete tiles on battens with counter-battens for ventilation
- Vapor-permeable underlay membrane (Siga Majcoat 150 SOB)
- Mineral wool with a thermal conductivity of 0.035 W/mK as insulation between rafters
- Vapor barrier
- Gypsum board ceiling
The cable and the opening in the roof run next to a soil vent pipe (sanitary vent) on the roof.
One worker suggested that it could be sealed with silicone or sealant.
How should the opening in the underlay membrane and the vapor barrier be properly sealed?
we have chosen a rooftop photovoltaic system for our roof, which was recently installed.
Now I am wondering how the hole created by the photovoltaic cables in the roof should be properly sealed. It has a diameter of about 3 cm (1.2 inches). Since the electrician who will complete the final work has not arrived yet, I would like to learn a bit more in advance than I currently know (which is nothing so far).
The roof structure (the house was built according to the 2016 energy-saving regulation standard and is very airtight according to an air tightness test, value 0.59):
- Concrete tiles on battens with counter-battens for ventilation
- Vapor-permeable underlay membrane (Siga Majcoat 150 SOB)
- Mineral wool with a thermal conductivity of 0.035 W/mK as insulation between rafters
- Vapor barrier
- Gypsum board ceiling
The cable and the opening in the roof run next to a soil vent pipe (sanitary vent) on the roof.
One worker suggested that it could be sealed with silicone or sealant.
How should the opening in the underlay membrane and the vapor barrier be properly sealed?
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AndreasPlü19 Aug 2018 09:21Thanks in advance for the specific advice about the vapor barrier; I will insist on that.
What about the underlay membrane? Are there similar products available? Or is a small hole not quite as critical?
What about the underlay membrane? Are there similar products available? Or is a small hole not quite as critical?
The collars can be used on a wide range of membranes/underlay sheets. You just need to order/apply the appropriate one for each product.
In the very first picture, you can also see that it can even be applied to OSB (oriented strand board) with the right tape.
Holes in membranes are always somewhat problematic because they compromise or completely undermine the function/purpose of the membrane.
In the very first picture, you can also see that it can even be applied to OSB (oriented strand board) with the right tape.
Holes in membranes are always somewhat problematic because they compromise or completely undermine the function/purpose of the membrane.
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AndreasPlü20 Aug 2018 10:48So, the person was here and applied a sealing collar onto the drywall, not onto the vapor barrier, because they couldn’t reach it. They claim this is okay since it’s now airtight. I suspect that’s not correct, right?
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