Hello,
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?
AndreasPlü schrieb:
So, the person was here and applied a sealing collar onto the drywall, not on the vapor barrier, because he couldn’t reach it there. He claims that this is fine now, as it’s airtight. I suspect that’s not correct, right?What nonsense. The drywall is airtight now, yes. But not the assembly where it actually matters! He should come back and do it properly. Remove the drywall, seal it correctly, then reattach the drywall. And yes, if it’s already been skim-coated, that will have to be redone as well.
A
AndreasPlü23 Aug 2018 11:34To be honest, I found the installation of the collar on the plasterboard unacceptable. I specifically called our site supervisor again, and the correct procedure is:
1. Collar, as already mentioned here.
2. Sealing tape applied according to the manufacturer’s instructions, along with a suitable sealing compound.
Before applying, the vapor barrier must be cleaned of dust, and the adhesive surface must not be touched.
I have now issued a written reminder and set a one-week deadline. If I don’t hear back or if the work is still done poorly, I will hire my own construction company or a roofing contractor and will of course withhold the corresponding payments from the progress installments.
It’s frustrating because this should only take about 30 minutes at most. Part of the plasterboard is already removed anyway.
1. Collar, as already mentioned here.
2. Sealing tape applied according to the manufacturer’s instructions, along with a suitable sealing compound.
Before applying, the vapor barrier must be cleaned of dust, and the adhesive surface must not be touched.
I have now issued a written reminder and set a one-week deadline. If I don’t hear back or if the work is still done poorly, I will hire my own construction company or a roofing contractor and will of course withhold the corresponding payments from the progress installments.
It’s frustrating because this should only take about 30 minutes at most. Part of the plasterboard is already removed anyway.
A
AndreasPlü15 Nov 2018 20:49By the way, I did it myself: I reduced the hole with the cables using overlapping sealing tape strips, placing several thin strips between the cables so that there was hardly any air left. Then I sealed the minimal gaps around the cables with a two-component vapor barrier sealant. After that, I applied sealing tape again, connecting the cables to the vapor barrier. Then I enclosed the cables in a thin cable conduit and filled around it with filler. I sealed the cable pipe outlet again with sealing tape as described earlier, so that the drywall within a radius of at least one meter shows no cracks or any other openings.
When possible, I will have a roofer (by any chance, is there one from the Stuttgart east area around here? 😉 ) check whether the roofing underlayment is properly taped. If not, they should apply proper sealing tape.
Why did I do it myself? After that experience, my trust in that tradesperson is zero. My construction consultant said it wouldn’t be too serious and that I could make it tight as described above.
When possible, I will have a roofer (by any chance, is there one from the Stuttgart east area around here? 😉 ) check whether the roofing underlayment is properly taped. If not, they should apply proper sealing tape.
Why did I do it myself? After that experience, my trust in that tradesperson is zero. My construction consultant said it wouldn’t be too serious and that I could make it tight as described above.
The same issue everywhere with the tradespeople. When something goes wrong, no one has the guts to fix their mistakes.
Right now, a Ytong house is being dismantled because there was hardly any adhesive under the first row of blocks... The entire ground floor was already built, fortunately without the ceiling.
Right now, a Ytong house is being dismantled because there was hardly any adhesive under the first row of blocks... The entire ground floor was already built, fortunately without the ceiling.
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