Vapor barrier, vapor retarder, wind barrier or nothing at all in a conservatory.
Hello
I'm building a sunroom and need to insulate the roof and floor joists. I'm trying to figure out this thing with vapor barriers. The room will have large glass sections designed for spring and autumn, and we don't plan to heat it except maybe occasionally. The roof has an air gap up to the roof decking that the builders who constructed the roof set.
Since it’s unheated, I’m clear that there shouldn’t be a vapor barrier, plastic. Then it starts to get more complicated.
Vapor brake is mentioned. Is it good? Is there any danger with it? It costs a bit, but not insanely expensive overall if it's worth it, so to speak.
Someone writes that you should put wind barrier/wind fabric on the inside too instead of plastic. It is cheaper than vapor brake. Disadvantages? Not as good? Unnecessary?
Someone else writes that in this situation you might as well skip fabric altogether.
I feel a bit lost in this. Help is gladly received.
//Jonas
I'm building a sunroom and need to insulate the roof and floor joists. I'm trying to figure out this thing with vapor barriers. The room will have large glass sections designed for spring and autumn, and we don't plan to heat it except maybe occasionally. The roof has an air gap up to the roof decking that the builders who constructed the roof set.
Since it’s unheated, I’m clear that there shouldn’t be a vapor barrier, plastic. Then it starts to get more complicated.
Vapor brake is mentioned. Is it good? Is there any danger with it? It costs a bit, but not insanely expensive overall if it's worth it, so to speak.
Someone writes that you should put wind barrier/wind fabric on the inside too instead of plastic. It is cheaper than vapor brake. Disadvantages? Not as good? Unnecessary?
Someone else writes that in this situation you might as well skip fabric altogether.
I feel a bit lost in this. Help is gladly received.
//Jonas
It is not the heating itself that is most critical here, but the moisture load at colder temperatures. For example, do you have plants there that are watered during spring and autumn? I don't have a direct answer to the question, but a vapor barrier might provide the least risk and the greatest flexibility for use.