Hello,
I have been working on our upper floor and installed a vapor barrier along the entire roof and sloping ceiling, down past the support beams (which we have sealed), stapling it at the roof edge, and pulling it 20-60 cm along the joists and stapling the vapor barrier there.
In the attic, we have clad the sloping wall with OSB and the knee wall with OSB x2 + gypsum and some insulation in between. On the floor in the attic, we have laid chipboard.
I did a pressure measurement the other day and we barely reached 5Pa. It then occurred to me that it must be because the vapor barrier doesn't overlap with the downstairs wall. I read a bit on the house manufacturer's drawings and we should have sewn/taped the vapor barrier to the wind screen. I would say that it's currently aligned with the vapor barrier. Now to my question. Will this become a problem with my ventilation system? Is there a risk of potential moisture/mold damage? FX creates negative pressure down there, but I'm mostly concerned that the vapor barrier is positioned like an L along the roof edge. I understand that I won't be able to achieve the pressure I desire, but is it vapor-tight enough? Do you think this will complicate any energy calculations in the future? I'm considering somehow digging my way into the attic, tearing up parts of the chipboard to tape the vapor barrier to the wind screen.
Thanks for all the help!
I have been working on our upper floor and installed a vapor barrier along the entire roof and sloping ceiling, down past the support beams (which we have sealed), stapling it at the roof edge, and pulling it 20-60 cm along the joists and stapling the vapor barrier there.
In the attic, we have clad the sloping wall with OSB and the knee wall with OSB x2 + gypsum and some insulation in between. On the floor in the attic, we have laid chipboard.
I did a pressure measurement the other day and we barely reached 5Pa. It then occurred to me that it must be because the vapor barrier doesn't overlap with the downstairs wall. I read a bit on the house manufacturer's drawings and we should have sewn/taped the vapor barrier to the wind screen. I would say that it's currently aligned with the vapor barrier. Now to my question. Will this become a problem with my ventilation system? Is there a risk of potential moisture/mold damage? FX creates negative pressure down there, but I'm mostly concerned that the vapor barrier is positioned like an L along the roof edge. I understand that I won't be able to achieve the pressure I desire, but is it vapor-tight enough? Do you think this will complicate any energy calculations in the future? I'm considering somehow digging my way into the attic, tearing up parts of the chipboard to tape the vapor barrier to the wind screen.
Thanks for all the help!
You will encounter problems with the air leakage that occurs. Increased energy consumption and issues with moisture damage. It's much worse with plastic that is not airtight than if you had skipped the plastic entirely. Because now the leakage becomes concentrated where the plastic is missing. Open up, redo, and do it right.