chris.12
2013-07-02 09:56:13
- #1
Hello everyone.
I am planning the construction of a new flat roof for a bungalow built in 1964. Due to various requirements, it will be built as an unventilated flat roof in timber construction with insulation between the rafters. I am aware of the difficulties of this construction and I also do not want to start a discussion about pros and cons, it is about one detail.
The construction from inside to outside will look as follows:
-Gypsum plasterboard ceiling
-Installation level / counter battens
-Intelligent vapor retarder
-Load-bearing layer with insulation between the rafters (24cm)
-Roof sheathing OSB
-Roof sealing PVC black (no greening, no gravel)
The roof will have a slope of 2-3%, which will be formed by wedges between the roof beams and the roof sheathing. So far so good, now to the question:
Due to an overhang on one side of the building, the insulation would be “open” between the wedges that form the slope to the subsequent box for the blinds. Although no rain would get in there, there is practically on this side a kind of ventilation present, which tapers with the slope towards the roof center. This ventilation of course does not work because it is neither continuous nor high enough.
Now the question arises whether it can be rather harmful to have this opening to the insulation (pseudo ventilation) at this point or not. Would it possibly be better to close the openings between the wedges?
I hope my description is somewhat understandable.
Many thanks and best regards from Hagen Christian
I am planning the construction of a new flat roof for a bungalow built in 1964. Due to various requirements, it will be built as an unventilated flat roof in timber construction with insulation between the rafters. I am aware of the difficulties of this construction and I also do not want to start a discussion about pros and cons, it is about one detail.
The construction from inside to outside will look as follows:
-Gypsum plasterboard ceiling
-Installation level / counter battens
-Intelligent vapor retarder
-Load-bearing layer with insulation between the rafters (24cm)
-Roof sheathing OSB
-Roof sealing PVC black (no greening, no gravel)
The roof will have a slope of 2-3%, which will be formed by wedges between the roof beams and the roof sheathing. So far so good, now to the question:
Due to an overhang on one side of the building, the insulation would be “open” between the wedges that form the slope to the subsequent box for the blinds. Although no rain would get in there, there is practically on this side a kind of ventilation present, which tapers with the slope towards the roof center. This ventilation of course does not work because it is neither continuous nor high enough.
Now the question arises whether it can be rather harmful to have this opening to the insulation (pseudo ventilation) at this point or not. Would it possibly be better to close the openings between the wedges?
I hope my description is somewhat understandable.
Many thanks and best regards from Hagen Christian