Hello!
I need help!
I have built a roof that in parts of the cabin becomes a so-called cold roof with cold attic space, but I want the kitchen to be open all the way to the ridge. Currently, I have the following:
roofing sheet
battens
condensation plastic
nothing more...
Should the insulation in the upcoming ceiling lie directly against the condensation plastic, or should it have a 5-10 cm gap against any plywood board as it does in the construction of cold roofs?
I need help!
I have built a roof that in parts of the cabin becomes a so-called cold roof with cold attic space, but I want the kitchen to be open all the way to the ridge. Currently, I have the following:
roofing sheet
battens
condensation plastic
nothing more...
Should the insulation in the upcoming ceiling lie directly against the condensation plastic, or should it have a 5-10 cm gap against any plywood board as it does in the construction of cold roofs?
A vapor barrier/vapor retarder should be installed on the warm side of the insulation, otherwise, there is a risk of getting condensation in the insulation....
Have been thinking a lot about the vapor barrier.
The cabin will be heated with a wood stove and only used for shorter periods during winter and summer. I've gotten the idea that any potential moisture in the insulation is better ventilated if no vapor barrier is installed on the inside, as it risks collecting condensation on the cold side during heating and cooling in the winter months.
Feedback and explanations are gratefully received!
The cabin will be heated with a wood stove and only used for shorter periods during winter and summer. I've gotten the idea that any potential moisture in the insulation is better ventilated if no vapor barrier is installed on the inside, as it risks collecting condensation on the cold side during heating and cooling in the winter months.
Feedback and explanations are gratefully received!
Without a moisture barrier, it works best with hygroscopic insulation, i.e., wood, shavings, cellulose, flax, and similar (not glass or stone wool).
However, if there is only a little insulation, say 10 cm, it might work reasonably well even with glass or stone wool. Plastic is primarily recommended for houses with permanent heating. If it is warmer on the outside than on the inside, condensation can form on the inside of the wall/plastic. However, the temperature difference in that direction is usually less significant than with +20°C inside and -10°C outside during winter.
So, it depends on insulation thickness, insulation material, possible maintenance heating, and to some extent the house's ventilation. (Besides how it is used.)
However, if there is only a little insulation, say 10 cm, it might work reasonably well even with glass or stone wool. Plastic is primarily recommended for houses with permanent heating. If it is warmer on the outside than on the inside, condensation can form on the inside of the wall/plastic. However, the temperature difference in that direction is usually less significant than with +20°C inside and -10°C outside during winter.
So, it depends on insulation thickness, insulation material, possible maintenance heating, and to some extent the house's ventilation. (Besides how it is used.)
This is a new build in the western mountains, I will put as much insulation as possible in the walls and roof to avoid freezing through the mornings in winter, vents will be drilled in suitable places in the kitchen, bedroom, and near the wood stove. The framing is 120x45 and I will have 45x45 lying inside to eliminate thermal bridges. The open roof will have at least 195 insulation since that is the measure of the roof truss, then I'm considering an additional layer of 95 lying under it to gain more insulation there!
Hmm... I thought you said you had condensation plastic in the construction now. I interpreted that as a vapor barrier. What is otherwise the purpose of it?
Unfortunately, there will never be any permanent heating, there might possibly be some form of solar vent but nothing more advanced.. (there's no electricity for miles)
Will be powering with solar panels and a generator, haven't finished planning that part yet, i.e. whether I should have a full 230v electricity network parallel with the 12v solar energy or just settle for an outlet near the solar panel setup for battery charging etc..
Will be powering with solar panels and a generator, haven't finished planning that part yet, i.e. whether I should have a full 230v electricity network parallel with the 12v solar energy or just settle for an outlet near the solar panel setup for battery charging etc..
Ok.
I belong to the old school and feel uncomfortable with non-hygroscopic insulation in buildings that are partially unheated. Especially not with as much insulation as you understandably want.
From experience (long) we know that old log cabins handle this type of use well. And they only have hygroscopic natural materials in them (solid wood, shavings, moss, clay, mortar, brick, untreated wood floors, etc.).
But, if you want to use glass/mineral wool, I think it might work with plastic.
However, there should be those who live further north than I do, who have better experience with cabins (not permanently heated) in harsher climates who can advise you.
I belong to the old school and feel uncomfortable with non-hygroscopic insulation in buildings that are partially unheated. Especially not with as much insulation as you understandably want.
From experience (long) we know that old log cabins handle this type of use well. And they only have hygroscopic natural materials in them (solid wood, shavings, moss, clay, mortar, brick, untreated wood floors, etc.).
But, if you want to use glass/mineral wool, I think it might work with plastic.
However, there should be those who live further north than I do, who have better experience with cabins (not permanently heated) in harsher climates who can advise you.