LowMagnificio
2017-02-21 21:29:10
- #1
Good evening,
we are currently deep in the renovation phase and the roof is once again a topic.
I have already searched through the internet but have not found a really clear answer to my question.
Briefly on the initial situation:
The house is from '79, located in Northern Germany, the roof is a collar beam roof with about 45°. The rafters are 16 cm deep. The USB is not vapour-permeable, so the insulation has been ventilated from behind since the beginning. The USB ends about 30 cm before the ridge. The attic is practically divided in length, one half is fully developed up to the gable, the other has an intermediate ceiling with an uninsulated loft above.
I have decided on an approved system of 12 cm insulation between the rafters and 6 cm insulation below the rafters. The old completely rotted glass wool has been removed, the new 12 cm is already installed, of course with ventilation behind it. The next step is the vapour barrier.
Now my question(s):
Due to the open USB, in the part of the attic developed up to the ridge, I am concerned that moisture from outside (rain, snow) could get into the insulation or even into the later cladding and cause greater damage there, is this concern justified?
If yes, can the USB be closed above the ridge without endangering the ventilation?
Another plan is to insulate the loft as well, here the same questions arise as above; in addition, the question of the usefulness came up.
Thanks in advance
we are currently deep in the renovation phase and the roof is once again a topic.
I have already searched through the internet but have not found a really clear answer to my question.
Briefly on the initial situation:
The house is from '79, located in Northern Germany, the roof is a collar beam roof with about 45°. The rafters are 16 cm deep. The USB is not vapour-permeable, so the insulation has been ventilated from behind since the beginning. The USB ends about 30 cm before the ridge. The attic is practically divided in length, one half is fully developed up to the gable, the other has an intermediate ceiling with an uninsulated loft above.
I have decided on an approved system of 12 cm insulation between the rafters and 6 cm insulation below the rafters. The old completely rotted glass wool has been removed, the new 12 cm is already installed, of course with ventilation behind it. The next step is the vapour barrier.
Now my question(s):
Due to the open USB, in the part of the attic developed up to the ridge, I am concerned that moisture from outside (rain, snow) could get into the insulation or even into the later cladding and cause greater damage there, is this concern justified?
If yes, can the USB be closed above the ridge without endangering the ventilation?
Another plan is to insulate the loft as well, here the same questions arise as above; in addition, the question of the usefulness came up.
Thanks in advance