Should you cover attic insulation with plastic?

Author: Mitchel Von  |  Last update: Wednesday, December 3, 2025

Yes, covering your insulation with a vapor barrier plastic before installing drywall is crucial. It prevents moisture buildup that can lead to mold, rot, and even structural damage. A polyethylene vapor barrier also adds a layer of fire protection, making your home safer.

Should I put plastic over attic insulation?

Big no-no! Plastic traps moisture, which can cause mold in your attic. Insulation needs to breathe. Think of it like a sweaty sweater under plastic - not comfy!

Should you put plastic over insulation in a ceiling?

Exposed insulation is at risk of catching fire if not covered properly because it is extremely flammable. Installing a fire retardant plastic sheeting over insulation slows the fire damage rate in the case of an adverse event.

Does attic insulation need to be covered?

If you have exposed fiberglass insulation, it's best to cover it to prevent the fibers from spreading in the occupied areas of your home. Unoccupied or low-traffic areas of your home, like a closed attic, don't necessarily need to have covered insulation.

Is it OK to cover attic insulation with plywood?

Hey there! 🙌 Yeah, you can totally put plywood planks on top of your insulation in the attic. Just make sure it's not compressing the insulation too much, ya know? 😅 You want to keep that air flow going and not mess up the R-value.

Insulating Attic Ceilings & Cathedral Ceilings (Phillips Vision: Episode - 63)

Does attic insulation need to breathe?

In order for insulation to do its job, sufficient airflow to the outside surfaces is required. Good ventilation in your attic will allow the moisture to get out. An attic that is well ventilated will reduce the roof surface temperature and eliminate moisture.

What can you cover insulation board with?

You should always install a vapor barrier to protect exposed ceiling insulation even if it's temporary. Consult with a building or safety expert to confirm where else in the structure a vapor barrier may be required.

Is it safe to leave insulation uncovered?

Exposed insulation can irritate your skin, eyes, and lungs. It can also be a fire hazard, especially in areas like the attic, basement, or garage. Plus, it can lead to mold and mildew growth, which can cause even more health issues.

Can you put a vapor barrier over insulation in attic?

In colder climates, where the home's heating system sees more use, the vapor barrier should typically be installed on the insulation's interior side. In warmer climates, where the home is often kept cooler, the vapor barrier should usually be installed on the exterior side.

Can you put Tyvek over insulation?

Yes. DuPont Tyvek® is compatible, and can be installed with foam insulation products.

Can you board on top of insulation?

Boards for loft flooring can be installed on top of insulation using plywood, wood, or plastics. Installing loft flooring and boarding over insulation helps save space, prevent heat loss, and increase home value.

Can I just use plastic as a vapor barrier?

You can use plastic if you put polyethylene between your drywall and the wall studs. This way, you should get a tighter wall without trapping moisture inside the exterior walls. If you are framing out a below-grade basement, however, do not use plastic as a vapor barrier.

Should you cover insulation?

If the insulation is ever disturbed, it can cause many health problems that are otherwise easily avoided. Breathing in fiberglass particles can irritate your eyes, lungs, and skin. This health risk is probably the best reason you want to cover your fiberglass insulation.

Should you put plastic over insulation in ceiling?

Plastic vapor barriers should only be installed in vented attics in climates with more than 8,000 heating degree days. 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.

Can you put too much insulation in attic?

While loft insulation is an effective way to improve energy efficiency and reduce heating costs, over-insulating can lead to several potential issues. Firstly, over-insulation can lead to poor ventilation in the attic, which can cause moisture buildup and increase the risk of mould growth.

Should attic insulation cover joists?

In unfinished attic spaces, insulate between and over the floor joists to seal off living spaces below.

Can I cover attic insulation with plastic?

Even if the attic space is unheated, it's typically warmer than the outside air in winter. If you have chosen unfaced batting insulation for your rafters, you should staple sheets of plastic over the batting to accomplish a moisture barrier.

Is it OK to compress attic insulation?

What Happens If You Compress Blown-In Insulation? Like batts, compressing blown-in fiberglass insulation improves the R-value per square inch while diminishing the overall R-value. Also like fiberglass batts, some amount of compression is OK if the cavity is completely filled.

Where should you not put insulation in the attic?

Also, when laying down additional insulation, work from the perimeter toward the attic opening. Never lay insulation over recessed light fixtures or soffit vents. Keep all insulation at least 3 inches away from recessed "can" lights, unless they are rated IC (Insulated Ceiling).

How to cover exposed insulation in an attic?

The good solution for this is a house wrap material (often referred to by the popular commercial brand Tyvek) which allows vapor to pass through while blocking water itself on the outside of the home. You can also put up a thin board, plywood, or even drywall, if the goal is simply to prevent accidental contact.

Is yellow or pink insulation better?

In general, the color of insulation doesn't equal better performance over another color. Whether it's pink, white, brown, or yellow—color doesn't influence dependability, reliability, or the products effectiveness.

What should you not do when installing insulation?

Leaving Too Many Gaps

One of the biggest problems DIY homeowners face is leaving too many gaps in their insulation. Gaps or insulation that isn't secured correctly can leave the building structure open to air and moisture leaks. Spray foam insulation is best for reaching into small cracks and any areas left open.

Can I use Tyvek to cover insulation?

Don't worry about that one. But with that strong air stream, breaking up of fiberglass strands and moving them around is a cause for concern. So, buy Tyvek, and use it to cover the insulation; staple it to framework. It is not a vapor barrier, so it is OK to put over the insulation.

What insulation can be left uncovered?

ECOCELL Blankets can be left exposed or even painted. Unlike other insulation materials, ECOCELL does not have to be covered with gypsum board. Leaving ECOCELL exposed is another reason ECOCELL is the cost effective solution for insulating basements and crawlspaces.

Can you use plastic for insulation?

What Plastic Is Used for Wire Insulation? Polyester films are often used for wire insulation due to their unique blend of dielectric, mechanical, thermal, chemical-resistant, and moisture-resistant properties.

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