Does Roxul Need A Vapor Barrier In Attic

I am in zone 4 right on the edge of zone 5 in long island ny.

Does roxul need a vapor barrier in attic.

Vapor barriers installed on the interior side of assemblies impede them from drying toward the interior this is a problem for air conditioned spaces and can be an issue when there is also a vapor impermeable material installed on the assembly s exterior creating a double vapor barrier wall assembly. Moisture transport by air is significantly higher 100x than moisture transport by diffusion. In some cases the vapor barrier also acts as the primary material in the air barrier system. Not every wall does.

In this moisture prone space you don t want water vapor from the ground drying to the inside of your home. You have loose fill insulation in the attic which doesn t have a vapor barrier. The basics of air sealing are covered in this article. So does roxul rockwool insulation need vapor barrier or not.

No you don t need a vapor barrier. Air sealing an attic. The vapor barrier does not need to be sealed to function adequately. It is important to note that air control is more important than vapor control.

I ve read that i need to use a vapor barrier but i ve also read that vapor barriers can cause houses to be moldy or can cause rot inside the walls because the walls cannot dry out properly. When it comes to the stairway leading into your attic you should heed the advice in this article. Our tutorial on how to insulate walls with rockwool is great if you need guidance. Youll see that i mention roxul a lot in that tutorial but roxul is exactly the same as rockwool.

This is primarily due to the kerdi board or wedi. Whether or not you need a vapor retarder hinges on three main factors. For a chart of vapor retarders by climate zone see the naima s insulation and vapor retarders in crawl spaces install a class i vapor barrier such as a vinyl liner on walls and floor. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.

To be able to answer this question correctly for your home there are a few factors you need to consider before any major attic insulation project. The theory is that part of the moisture vapor in the house is actually blocked by the drywall and paint on the. I keep getting mixed results when google searching some say it depends what climate zone you are in i m in climate zone 3 anyone here knows if that means i need a vapor barrier or not. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.

What you need is an air barrier that is at every step of the way you have to pay attention to airtightness.