ᐅ Drafts or wind between the roof joists in the converted attic space
Created on: 2 Feb 2021 08:36
R
rbertHello everyone.
At the end of 2019, we had our attic converted, including the knee wall. The floor was already made of tongue-and-groove boards, and we only installed a carpet on top. The staircase and door were also installed.
In the years before, the attic was used as storage. We built the house in 2008 (prefabricated house), and back then, the attic was not insulated. Therefore, the vapor barrier stops at the ceiling of the upper floor.
Anyway, after the attic conversion, we noticed that it cools down very quickly. Especially when the door to the upper floor is closed, this becomes noticeable.
After a long search, I found out that the wind (we live in a windy, exposed location) passes through the roof beams. It then comes through the tongue-and-groove boards and the carpet. Probably because the vapor barrier coming from above ends at the ridge beam and the vapor barrier from below is attached to the roof beams — in between, the wind whistles in from the roof.
So shortly after, we had cellulose blown in as loose insulation between the roof beams. With little success.
Two months ago, I decided to place a kind of windstopper (insulation wrapped in vapor barrier foil) between the roof beams (see also attachment, point 3). It helped somewhat, but we have still noticed in recent days, during continuous wind, that the attic cools down again (at 2°C (36°F) outside temperature, the attic temperature drops to 10°C (50°F) after 3 days).
Now the question:
In my desperation, I am thinking to spray mounting foam around all sides of the windstoppers, i.e., between the roof beams and the ridge beam, because I suspect the problem originates there.
Installing a vapor barrier film retrospectively between the roof beams is not possible in the tight knee wall space. Hence the idea with the mounting foam.
Alternatively, I am considering removing the carpet from the tongue-and-groove floor and then laying a vapor barrier film with impact sound insulation/laminate on top. But I am a bit worried about mold issues with that approach.
Feel free to take a look at the drawing; maybe it explains things better.
Otherwise, please just ask.
I am grateful for any advice!
Thank you!
At the end of 2019, we had our attic converted, including the knee wall. The floor was already made of tongue-and-groove boards, and we only installed a carpet on top. The staircase and door were also installed.
In the years before, the attic was used as storage. We built the house in 2008 (prefabricated house), and back then, the attic was not insulated. Therefore, the vapor barrier stops at the ceiling of the upper floor.
Anyway, after the attic conversion, we noticed that it cools down very quickly. Especially when the door to the upper floor is closed, this becomes noticeable.
After a long search, I found out that the wind (we live in a windy, exposed location) passes through the roof beams. It then comes through the tongue-and-groove boards and the carpet. Probably because the vapor barrier coming from above ends at the ridge beam and the vapor barrier from below is attached to the roof beams — in between, the wind whistles in from the roof.
So shortly after, we had cellulose blown in as loose insulation between the roof beams. With little success.
Two months ago, I decided to place a kind of windstopper (insulation wrapped in vapor barrier foil) between the roof beams (see also attachment, point 3). It helped somewhat, but we have still noticed in recent days, during continuous wind, that the attic cools down again (at 2°C (36°F) outside temperature, the attic temperature drops to 10°C (50°F) after 3 days).
Now the question:
In my desperation, I am thinking to spray mounting foam around all sides of the windstoppers, i.e., between the roof beams and the ridge beam, because I suspect the problem originates there.
Installing a vapor barrier film retrospectively between the roof beams is not possible in the tight knee wall space. Hence the idea with the mounting foam.
Alternatively, I am considering removing the carpet from the tongue-and-groove floor and then laying a vapor barrier film with impact sound insulation/laminate on top. But I am a bit worried about mold issues with that approach.
Feel free to take a look at the drawing; maybe it explains things better.
Otherwise, please just ask.
I am grateful for any advice!
Thank you!
bauenmk20202 Feb 2021 09:28Do you have an IR thermometer and have you measured the temperatures of the building components (especially rafters, tongue-and-groove boarding)? How is the room heated, directly or indirectly through the rooms below?
What happens if the "ventilation" is completely turned off – how do you plan to remove humid air from up there? I think only if you can still ensure this after your measures would it be appropriate to stop the draft.
What happens if the "ventilation" is completely turned off – how do you plan to remove humid air from up there? I think only if you can still ensure this after your measures would it be appropriate to stop the draft.
Hello. Unfortunately, I don’t have an IR thermometer.
I also don’t quite understand the question. Currently, moisture is not an issue, only the wind.
What will happen if I completely turn off the “ventilation,” I don’t know, as that is exactly the solution I am looking for 🙂
The attic is indirectly heated through the rooms below and the open door leading to the hallway.
No matter how cold it is outside, this “heating method” is enough to warm the attic to 21°C (70°F). Additionally, I have IR panels, but I only need to use them occasionally.
However, as soon as it gets windy, you can feel a slight (or noticeable) draft near the floor, which cools the room down.
I also don’t quite understand the question. Currently, moisture is not an issue, only the wind.
What will happen if I completely turn off the “ventilation,” I don’t know, as that is exactly the solution I am looking for 🙂
The attic is indirectly heated through the rooms below and the open door leading to the hallway.
No matter how cold it is outside, this “heating method” is enough to warm the attic to 21°C (70°F). Additionally, I have IR panels, but I only need to use them occasionally.
However, as soon as it gets windy, you can feel a slight (or noticeable) draft near the floor, which cools the room down.
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