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.
Do i need a vapor barrier for attic insulation.
Insulation vapor barrier with radiant barrier.
The heat being lost from the house below warmed up the attic so that moisture was lost through the vents as vapor.
Our insulation vapor barrier can also reduce condensation mold and degradation by controlling water vapor migration.
After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.
The following are a few simple steps to help you undertake the task properly so your vapor barrier retains heat without damaging the insulation.
With spray foam unlike with loose fill or batts you must cover the soffit vents they aren t needed to keep the roof cool.
Not every wall does.
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.
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.
Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case.
Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers.
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.
Foam blocks airflow needs no vapor barrier and has a higher r value per inch than loose fill or batts so you ll get more protection with less depth.
Because it s nearly impossible to seal penetrations in the ceiling the reality is water vapor will get into the attic.
Plastic vapor barriers should only be installed in vented attics in climates with more than 8 000 heating degree days.
Crawl space ninja insulation vapor barrier is a blanket insulation vapor barrier designed to provide a thermal break and moisture barrier in crawl spaces.
Attic vapor barrier detail for cold climates.