Fire resistance rating of roof assembly in OBC part 3

[sunyaer]

In Ontario building code 2012 part 9, table 9.10.8.1. sets out floor assembly and roof assembly fire resistance rating, while in part 3, from 3.2.2.20. to 3.2.2.83., there are some articles which spell out roof assembly fire resistance rating, but most of these articles do not have a requirement for roof assembly fire resistance rating, is there some where in part 3 which covers all the articles from 3.2.2.20. to 3.2.2.83. for requirement of roof assembly fire resistance rating?

 

[tmurray]

No, they are individually identified in 3.2.2.20 to 3.2.2.83.

 

[sunyaer]

No, they are individually identified in 3.2.2.20 to 3.2.2.83.

Only some articles of 3.2.2.20 to 3.2.2.83 mention roof assembly fire resistance rating, while most of these articles do not, where to find information to determine the roof assembly fire resistance rating in these articles without the information?

 

[tmurray]

If the code is silent, then the construction is unregulated.

 

[sunyaer]

If the code is silent, then the construction is unregulated.

Does that mean the roof assembly would be 0 hour fire resistance rating?

 

[tmurray]

It would not be required to meet any fire resistance rating. Typically when we talk about something rated as "0 hour", we are talking about a fire separation that does not need to be fire rated, but would still needs to prevent the spread of smoke through the building. Also sometimes called a "smoke seal" by trades people.

In this industry, you need to be very careful about terminology. Different definitions of a word can completely change the meaning of a requirement.