FAQ

FAQ about the effect of Code for fire protection design of building (FB50016-2014) to using rigid PU foam in building

Code for fire protection design of building (GB50016-2014) has been issued and will be executed from May 1, 2015. As organic insulation, can rigid PU foam be used in building insulation after the code is issued?

According to Clause 6.7.1 of Code for fire protection design of building (GB50016-2014), class A insulation is preferred in interior insulation system and exterior insulation system of building and class B2 insulation is not preferred. Class B3 insulation is strictly prohibited. Rigid PU foam can reach B2 and B1, so it can be used in building as insulation material.

Does rigid PU have any limitations in building insulation?

As insulation material, rigid PU foam can be used in roof and wall insulation. The two applications have different requirements.

Roof insulation

According to Clause 6.7.10 of Code for fire protection design of building (GB50016-2014): for exterior roof insulation, when the fire resistant  level of roof substrate is equal or greater than  1.0 hour, insulation materials need to meet B2 Class as minimum requirement; when the fire resistant level of roof substrate is less than 1.0hour, B1 Class or above should be used. This means B2 rigid PU foam can be used on concrete roof insulation and B1 rigid PU foam can be used on metal deck insulation.

Wall insulation

Exterior wall internal insulation:

According to Clause 6.7.2.2 of Code for fire protection design of building (GB50016-2014): For low occupant density building, Class B1 and above insulation materials with low smoke, low toxicity shall be used. This means Class B1 insulation can be used in internal insulation system for most of residential buildings.

Exterior wall external insulation:

According to item 6.7.5 of Code for fire protection design of building (GB50016-2014),

For residential building:

Class A insulation shall be used when the height of the building is more than 100m;
B1 or above shall be used when the height of the building is more than 28m, but no more than 100m;
B2 or above shall be used when the height of the building is not more than 27m;

This means B2 rigid PU foam can be used in buildings when total height is no more than 27m; B1 rigid PU foam can be used in buildings with total height of not more than 100m.

For public and office building:

Class A insulation shall be used when the height of the building is more than 50m;
B1 insulation or above shall be used when the height of the building is more than 24m but not more than 50m;
B2 or above shall be used when the height of the building is not more than 24m;

This means B2 rigid PU foam can be used in public building and office building when total height is no more than 24m; B1 rigid PU foam can be used in public building and office building when total height is no more than 50m.

For curtain wall building:

Class A insulation shall be used when the height of the building is more than 24m;
Class B1 or above shall be used when the height of the building is not more than 24m;

This means B1 rigid PU foam can be used in curtain wall building when total height is no more than 24m.

Is any extra fire protection measures needed when rigid PU foam is used as insulation?

Same as other organic insulations, when using rigid PU foam as insulation in building, other fire protection measures eg. Fire barrier are needed. Details can be found in chapter 6.7 of Code for fire protection design of building (GB50016-2014)