Mar 2007

Plastics In Construction

Plastics are increasingly being used in construction for their relatively low cost compared to other materials and as well as energy savings as an insulation material. Their use presents other challenges to the structure itself. Examples include:

  • A roof recover using spray on insulation on the rooftop can cause the roof to be considered combustible, despite what it previously was.
  • Insulated metal panels, used as walls and ceiling, increase the combustible loading and in some cases become the primary fire hazard.
  • Exterior insulation finish systems (EIFS) can be susceptible or damage by windstorms (either by wind pressures or from projectiles).

You should consider the following items when using plastics in construction and the following perils:


Avoid using exposed expanded plastics in construction. Fire additives, though showing good performances in tests standards such as ASTM E-84, do not necessarily continue when the plastics are subject to full-scale fire tests such as FM Global Approval standard 4880 (aka Corner Test). Thermal barriers should be applied over interior surfaces, such as Approved/Listed retardant coatings or Portland cement plaster on metal lath. The thermal barriers should provide sufficient resistance to heat transfer before automatic sprinklers activate.

Metal insulated panels should show good performance in the Corner Test. Avoid using metal panels used in ceiling systems where the plastic is expanded polystyrene; if used, it should be provided with a thermal barrier.

Exposed plastic panels such as PVC or fiber-reinforced plastic (FRP) can be used provided they do not exceed certain thicknesses, weights and heights.

The installation of the construction system involving plastics should follow the manufacturer’s specifications as well as the Approval/Listing conditions for the system.

The driving force behind sprinkler protection in a building may be the plastic used in the construction instead of the occupancy, especially if thermal barriers are not involved.

Maintain sufficient clearance between heat sources and the plastic materials.

Any damage to thermal barriers or metal facing to insulated panel should be promptly repaired. Any manufacturer’s specifications for repair should be strictly followed.


Wind loads on exterior walls and the roof should meet the current codes for the site.

Areas where small and large missile impact may occur may not make the use of the plastic-based construction system desirable. Though modified systems may prevent full penetration into the building, windstorm damage may still create architectural (e.g. cladding) damage.

Risk Logic, Inc. can be of assistance in ensuring that all the above safeguards are being followed in an effort to avoid a major property loss.

Risk Logic, Inc. can be of assistance regarding fire protection Codes and Regulations. We can ensure that the above codes as well as NFPA and FM Global standards are being followed in an effort to avoid a major property loss.