Which insulation Cannot be left exposed must be covered by a 15 minute thermal barrier?

Author: Enoch Bradtke  |  Last update: Wednesday, August 13, 2025

Thermal Batt Insulation (Foil Faced) Cannot be left exposed — must be covered by a 15-minute thermal barrier.

What must be covered by a 15 minute thermal barrier?

The International Building Code (2006 IBC) requires foam plastic insulation to be separated from a building's interior by an approved 1/2 inch drywall thermal/fire barrier or equivalent thermal barrier. which prevents the temperature from rising above 250°C Degree F (121°C) for a period of 15 minutes.

Is plywood a 15-minute thermal barrier?

1.5, 15/32” plywood or OSB prescriptively meet this thermal barrier requirement for roof assemblies. Beside gypsum wall board, plywood and OSB, other materials such as T&G decking may meet the 15 minute thermal barrier requirement.

What insulation board can be left exposed?

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 faced insulation be left exposed?

Faced insulation

Kraft or foil facedFaced insulation is a batt or roll of fiberglass insulation with an attached kraft paper or foil facing. Kraft and standard foil facings can burn and must not be left exposed.

Exposed Insulation Thermal Barrier Protection

Can ICF be left exposed?

If you can either shade it or paint/cover it with an appropriate material to take the brunt of the sun exposure it should be fine for as long as you like, but vendors typically recommend leaving uncovered and exposed to sunlight for no more than 3 months.

What is acceptable thermal barrier?

The thermal barrier may be ½” gypsum board, or a material that is tested in accordance with and meets the acceptance criteria of NFPA 275 Temperature Transmission Fire Test and the Integrity Fire Test. The purpose of the thermal barrier is to limit the temperature rise of the foam plastic.

What is DC315 thermal barrier?

DC315 Fireproof Paint is a fully tested and approved intumescent coating to meet 15-minute alternative Thermal Barrier and Ignition Barrier protection over Spray Polyurethane Foam (SPF). DC315 meets IBC/IRC codes in the USA, Canadian NBCC and many international Building Code Requirements.

What is the difference between faced and unfaced insulation?

Different parts of the house demand different insulation materials. For example, faced insulation is better used on exterior walls, attic ceilings, basements, and bathrooms, while unfaced one is commonly used on interior walls, crawl spaces, or between floors.

Is OSB a 15-minute fire barrier?

A fire-rated OSB product like LP FlameBlock offers both flame-spread resistance and burn-through resistance in the same panel, as verified in tests like the 30-minute Class A Flame Spread Rating (ASTM E84, UL723) and 15-minute Thermal Barrier Protection test (UBC 26-2).

Do I have to cover rigid foam insulation?

While there are no UV rays to destroy the foam board's insulative properties, interior exposure can create a fire hazard. Therefore, to qualify a building for an occupancy permit, most jurisdictions in North America demand that a thermal barrier, like drywall, cover the foam board.

Can plywood be used as a thermal barrier?

Common Types of Thermal Barriers

Plywood: While not as common as drywall, plywood can also serve as a thermal barrier in some instances.

Can spray foam insulation be left exposed?

The Bottom Line About Covering Up Spray Foam Insulation

Regardless of whether or not spray foam is visible, it must be covered. In many applications, spray foam is covered through the thermal barrier of drywall. In other applications, spray foam receives a coating to protect it from UV rays or water damage.

Is fiberglass insulation a thermal barrier?

Fiberglass insulation is very good when it comes to energy efficiency. By creating a thermal barrier that keeps your home warm in winter and cool in summer, it reduces the strain on your heating and cooling systems and lowers your electricity bill.

What is the maximum temperature for thermal barrier coating?

State-of-the-art zirconia-based TBCs only have a temperature limit of about 1200 degrees Celsius (°C), but new TBC materials that can operate at elevated temperatures of 1300°C and above are needed to continue to push turbine operating temperatures higher and achieve the associated energy efficiency gains.

What is a 15 minute thermal barrier?

The International Building Code (IBC) requires that foam plastic insulation be separated from a building's interior by 1/2 inch drywall or equivalent thermal barrier. The aim is to prevent the insulation's temperature from rising above 250 Degree F for 15 minutes.

Can you paint over DC315?

Yes, you can paint over DC315. It is compatible with a variety of topcoats, including water-based acrylics. We have tested with various protective topcoats and aesthetic topcoats. All are listed in our master specifications to meet the needs of your specific application.

What is the best thermal barrier coating?

Yttria-Stabilized Zirconia (YSZ)

YSZ is one of the most commonly used types of ceramic-based Thermal Barrier Coatings (TBCs). It is composed of zirconia (ZrO2) with a small amount of yttria (Y2O3) added to stabilize the crystal structure.

Does spray foam insulation require a thermal barrier?

A thermal barrier is required to cover spray foam in all applications and is what separates the spray foam insulation from occupants and the interior of a living space. It's typical for drywall, plywood, or gypsum board to be the materials used as barriers for your room walls and ceilings.

What is the thermal limit?

By thermal limit, we mean the limit set by temperature rise. The output limit of most of electrical machines is basically a thermal limit. For example, if we exceed the rated load of a generator, generator coils will overheat.

What is an example of a thermal barrier?

Examples of effective thermal barriers include:
  • Insulation materials such as fiberglass, cellulose, and spray foam.
  • Reflective foil barriers.
  • Multi-layer insulation systems.
  • Low-E (low-emissivity) coatings on windows.
  • Vacuum insulated panels.
  • Aerogel insulation.
  • Radiant barriers made of metalized films or foil-faced materials.

What type of insulation can be left exposed?

Batts with a special flame-resistant facing are available in various widths for basement walls and other places where the insulation will be left exposed.

Does ICF need to be covered?

ICFs must only be protected from sunlight and impacts through coverings such as brick, stone, stucco, EIFS, siding, etc.

Can rigid insulation be left exposed?

The following are recommendations when storing THERMAX ci exterior insulation: Do not leave THERMAX ci Exterior Insulation products exposed to direct sunlight for longer than 180 days. Store above standing water. Keep product tarped or covered to protect from weather.

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