Do You Need Vapor Barrier Blown Insulation Attic

Due to this inevitable fact it s actually better to omit a vapor barrier between the insulation and drywall of the ceiling below the attic.

Do you need vapor barrier blown insulation attic.

Not every wall does. You do not need a vapor barrier. Most of the blanket insulation types have vapor barriers incorporated and can be very effective if installed properly. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.

This means also the access hatch. The best approach for a vented attic in a cold climate is installing a layer of drywall with a good coat of latex paint the paint creates a semi permeable vapor barrier. The best way to answer this question in addition to considering the factors above would be to talk to a professional. Plastic vapor barriers should only be installed in vented attics in climates with more than 8 000 heating degree days.

Do not add a vapor barrier on top of the insulation in your attic since the paper facing on the existing insulation is the vapor barrier. If you are not sure if you need insulation in your walls follow along with this flow chart. The basics of air sealing are covered in this article. No the best option is to install un faced or loose fill fiberglass or cellulose on top of your drywall.

Air sealing an attic. The paper facing contains a layer of impermeable asphalt that prevents water vapor from passing through it. Your first job after the studs are in place is to fill those walls with insulation. You can forego the plastic and use a vapor retarder kraft faced insulation or latex ceiling paint in all other climates except hot humid or hot dry climates.

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. Thousands of houses have had insulation blown in without incident mostly because old houses are so leaky that there is little or no chance for water vapor to build up to cause the insulation to. You will see on which side is the vapor barrier. To assure proper protection of the vapor barrier you will need to cover the entire area of 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. Since you already have insulation if there was a moisture problem you probably would have noticed signs of it already. Lucy no you don t need a vapor barrier. What you need is an air barrier that is at every step of the way you have to pay attention to airtightness.