Does Attic Insulation Need Vapor Barrier
This barrier is meant to keep moisture from getting to the insulation in the walls and ceilings and it is required by building codes when insulating most houses.
Does attic insulation need vapor barrier. Because it s nearly impossible to seal penetrations in the ceiling the reality is water vapor will get into the attic. The following are a few simple steps to help you undertake the task properly so your vapor barrier retains heat without damaging the insulation. The heat being lost from the house below warmed up the attic so that moisture was lost through the vents as vapor. Some regions don t require a vapor barrier.
Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case. No you don t need a vapor retarder class i or otherwise. By chris moore fiberglass insulation must stay dry to be effective. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.
This acts as a barrier to keep heated moist air from rising up into the attic during cold weather. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. More insulation installation tricks and tips work from the perimeter of the attic toward the door or hatch so that you don t trample all over the insulation you just put in. Not every wall does.
By the time you paint the drywall though you ve brought it into the class iii vapor retarder range between 1 and 10 perms and even less water vapor will diffuse through. Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers. Seal the air leakage pathways. Most forms of attic insulation benefit from the addition of a vapor barrier to protect them from the harmful effects of moisture which can reduce their effectiveness over time.
Whether or not you need a vapor retarder hinges on three main factors your climate your home and the location of the wall you re insulating.