Home / News / Ignition Barrier & Thermal Barriers – Spray Foam

Ignition Barrier & Thermal Barriers – Spray Foam

Fireproofing your spray foam application is one of the most necessary steps before leaving a job and requires usually either a ignition barrier or thermal barrier . Thermal barrier and ignition barrier are essential to protecting those inside in the case of a fire in the residence or building. Ignition barriers may not be required in your area, but it is always recommended as it is another area and layer of protection for the building. So now you may be wondering, what does thermal or ignition barrier do?

Thermal Barrier
Thermal Barrier is applied between foam and interior space to delay the temperature of the foam during a fire situation and delay/prevent the foams involvement in a fire.  To be classified as a thermal barrier, the material must resist severe fire exposure for a minimum of fifteen (15) minutes. Thermal barriers are designed for fire inside the living space to not have access to continuous fuel, allowing the flames to die down, allowing resident occupants more time to escape. The IBC define an approved thermal barrier as one which is equal in fire resistance up to 1.2 inch gypsum wallboard. Thermal barriers can be approved by the IBC lists as long as it serves as a barrier separating living spaces.

Ignition barrier
An exception to thermal barrier requirement in attics and crawlspaces are made only for where entry is used only to make repairs or maintenance or service utilities.  In these cases foam insulation is protection against ignition using a prescriptive ignition barrier such as 1/4 thick wood panels, 3/8″ particle board, 1/4″ hardboard 3/8″ gypsum board.

So what do you use and when  you use a thermal and ignition barrier?

The SPFA gives a interpretation of building code criteria located below when you are using ignition barrier and thermal barriers in combination with SPF:

  • Thermal Barrier: Whenever the attic or crawlspace is used or could be used as an auxiliary living space or for storage. Attics and crawlspaces having access doors; pull down or fixed stairs; or flooring pathways.
  • Ignition Barrier: Whenever the attic or crawlspace is not or could not be used as an auxiliary living space or for storage. Criteria include difficulty of entry ( such as a hatch or opening).  not easily accessible and lack of flooring.

If you are looking for a Thermal  & Ignition barrier product you can visit our online store for DC315 that comes in grey or white. If you are only needing ignition barrier for your application you can contact us for our selection of ignition barrier open cell foams.  For more information please visit the SPFA website for more resources at sprayfoam.org.


If you have any other questions, reach out to us via email, Facebook, or call us at 877-737-4362.

Back to News