Is an 'opening' that has the same rating as the wall, really an 'opening'?

[Ryan Schultz]

Is it possible to have 'openings' in a double fire wall right at the property line, if the fire doors in the walls have the same rating as the wall itself?

I guess I understood if the 'opening' has the same rating as the wall itself, its not really considered an opening as defined per 705.8 Openings.

 

[RLGA]

If it opens, it's an opening regardless of its fire-resistance rating.

Additionally, the testing methods for opening fire-ratings are not the same as those for walls. Walls are required to pass a radiant heat portion of the test method that is not present in the methods for openings. Fixed glazing assemblies can be considered walls if they pass the same tests as those for walls; thus, the exception per IBC Section 716.2.

BTW, if this is a legal property line, openings on exterior walls with a fire separation distance of less than 3 feet from the property line are not permitted per Table 705.8. If this is an imaginary lot line, locate it where it will not impact the openings of existing buildings and will benefit the current phase. Then relocate the imaginary lot line when the next phase is constructed.

 

[classicT]

I believe that the intent of your question is not related to 'fire walls'. If it is a fire wall, then 706.1.1 will make you aware that openings are not permitted.

706.1.1 Party Walls
Any wall located on a lot line between adjacent buildings, which is used or adapted for joint service between the two buildings, shall be constructed as a fire wall in accordance with Section 706. Party walls shall be constructed without openings and shall create separate buildings.

Exception: Openings in a party wall separating an anchor building and a mall shall be in accordance with Section 402.4.2.2.1.
​

What I do believe that your picture represents is two exterior rated walls with 0-ft offset to property line. If it is this case, then Tables 601 and 602 will prescribe the hourly rating of the wall and openings are regulated by Table 705.8. This will ultimately lead you to the conclusion that openings in exterior walls less than 3-ft from property lines are not permitted.

​

 

[classicT]

If it opens, it's an opening regardless of its fire-resistance rating.

Additionally, the testing methods for opening fire-ratings are not the same as those for walls. Walls are required to pass a radiant heat portion of the test method that is not present in the methods for openings. Fixed glazing assemblies can be considered walls if they pass the same tests as those for walls; thus, the exception per IBC Section 716.2.

BTW, if this is a legal property line, openings on exterior walls with a fire separation distance of less than 3 feet from the property line are not permitted per Table 705.8. If this is an imaginary lot line, locate it where it will not impact the openings of existing buildings and will benefit the current phase. Then relocate the imaginary lot line when the next phase is constructed.

Damn Ron, beat me to it. I've got to type faster or something.

 

[cda]

Some rated walls require the same rating on the opening protection.

 

[RLGA]

Some rated walls require the same rating on the opening protection.

That's true, but, to be clear, having the same rating doesn't mean equal protection.

 

[Bryant]

What about the percentage of openings in a rated assembly separating two fire areas? Believe it was 25 % of the developed wall length in any other setting...
Agree on the principal as indicative of a townhouse wall separation of units as the pics seem to imply