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Existing Dormitory Corridor wall rating requirement

Existing Dormitory Corridor wall rating requirement

New postby shahin on Mon Sep 12, 2016 4:57 pm

I have an existing dormitory building for the University of Southern California. We are trying to upgrade the electrical system. The building is fully sprinklered. I have two questions.
1-How much upgrade I am required to do by code, by the only scope is to upgrade the electrical system.
2-Is the corridor wall required to be rated?
shahin
 
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Re: Existing Dormitory Corridor wall rating requirement

New postby Jerry Peck - Codeman on Mon Sep 12, 2016 9:10 pm

shahin wrote:I have an existing dormitory building for the University of Southern California. We are trying to upgrade the electrical system. The building is fully sprinklered. I have two questions.
1-How much upgrade I am required to do by code, by the only scope is to upgrade the electrical system.


That depends on what you mean by "We are trying to upgrade the electrical system" and to the extent of that upgrade.

Is it a total upgrade, a partial upgrade, adding new circuits, etc?

2-Is the corridor wall required to be rated?


That depends on the code the building was constructed under, but your need (if I am understanding the question) is knowing what you have to do in making membrane and/or through penetrations to those corridor walls - correct?

Without knowing what code was in effect at the time of construction (that would be the applicable code to what was required at the time of construction, and the applicable code for knowing what to do now), as such, I can only address what is "typical" for those walls - "typically" the rating of those walls would be a 1-hour fire resistance rating, but could be 2-hour fire-resistance rating.

If you are making membrane penetrations, use steel electrical boxes and use putty pads which are listed for use applied to the inside of the boxes as it is not feasible to apply putty pads to the back side of the steel electrical boxes in a closed up wall. Also, to my knowledge, no putty pads are available for non-metallic electrical boxes, which means location/spacing of boxes which are membrane penetrations becomes a real pain because you have to know the construction of the wall and location of other membrane penetrations, on either side of that wall, and, making things more difficult, when the code/listing limits 100 square inches of boxes in 100 square feet of wall space ... that does not mean a 10 foot by 10 foot area, that means what it says "100 square feet", which could be 1 foot by 100 feet or one-half foot by 200 feet, and given the size of a box and that most boxes are installed at the same height, the size limit of 100 square inches is exceeded very quickly. If you are making membrane penetrations, a lot needs to go into planning the locations and types of electrical boxes.

If you are making through penetrations, I recommend using 2-hour rated penetrations as it is 'unlikely' that the wall is a 3-hour rated wall in that location, and while the wall is 'likely' to be a 1-hour rated wall, it is 'not unlikely' that the wall is a 2-hour rated wall.

You are required to maintain the fire rating of that wall, don't take a chance on what its rating is.

Also, when running metallic conduit or MC cable, check the "T-Rating" of the through penetrations where applicable (may not be applicable in all locations) because a fire on one side of a rated wall with metal penetrating the wall can heat up the metal coming out the other side of the wall, and that heated metal (which is now 'hot') can cause a fire on the other side of the wall, spreading the fire to the other side of the rated wall without the fire actually having to go through the rated wall.
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Re: Existing Dormitory Corridor wall rating requirement

New postby shahin on Tue Sep 13, 2016 10:47 am

shahin wrote:I have an existing dormitory building for the University of Southern California. We are trying to upgrade the electrical system. The building is fully sprinklered. I have two questions.
1-How much upgrade I am required to do by code, by the only scope is to upgrade the electrical system.
2-Is the corridor wall required to be rated?


Constructed in 1963, 4 story, type I, Fully Automatic Sprinklered, Uniform Building Code
Corridor walls are not rated at the present time.
The current scope is to:
a)- Add circuits to rooms.
b)- Increase panel sizes.
c)- Increase transformer sizes.
d)- Changing lighting to LED.

Am I required to rate corridor walls, which will be very difficult and expensive to do.
shahin
 
Posts: 3
Joined: Thu Sep 08, 2016 4:48 pm

Re: Existing Dormitory Corridor wall rating requirement

New postby Jerry Peck - Codeman on Tue Sep 13, 2016 11:32 am

shahin wrote:Constructed in 1963, 4 story, type I, Fully Automatic Sprinklered, Uniform Building Code
Corridor walls are not rated at the present time.
The current scope is to:
a)- Add circuits to rooms.
b)- Increase panel sizes.
c)- Increase transformer sizes.
d)- Changing lighting to LED.

Am I required to rate corridor walls, which will be very difficult and expensive to do.


Ah, now I am on the same page you are:
a) - Only if required by your Existing Building code (if there is an Existing Building code), in the last 10 to 15 years these are adopted using the ICC Existing Buildings code as their base code, then local amendments are made to the base code.
b) - Or only if required by a Property Maintenance code (similar in adoption to the an Existing Buildings code over the last 10 to 15 years except based on ICC Property Maintenance code).
c) - Only if required by the Fire Marshal (possible if they use a Fire Prevention code with such a requirement).
d) - All of the above typically base their upgrade requirements on structural changes or changes to walls/horizontal assemblies which are now required to be rated ... typically ... such upgrades are not required for electrical, mechanical, plumbing (MEP) upgrades unless done at the same time as structural changes or changes to walls/horizontal assemblies.
e) - There may be requirements based on the total value of the work versus the before-work appraised value of the structure/building in that if the total value of the work exceeds 50% of the value of the structure (before the work is done), then, yes, it is quite possible that the ENTIRE STRUCTURE may be required to be brought to the code as applicable for new construction (current code).

If only your electrical work is being done, the value of the work likely does not meet the 50% threshold. However, if you are doing that much work, it is likely that other work is also being performed, and the total value of all work would likely be used to calculate the 50% threshold.

Keep in mind that some AHJ track the work for 1 year to 10 year periods, or whatever time periods they elect to use ... and some do not even apply a time period, they simply take each work at its own value. There is no consistency in how this is addressed across the country, or even how it is addressed within one state, and sometimes not even addressed the same throughout one county.

With so many variables in play between all the possible codes, local amendments to those codes, the Fire Marshal, the value of the work ... the only specific answer to your question can come from your local AHJ and/or Fire Marshal.

I suspect that their answer will be that if no work is being done on those walls, other than you possibly making penetrations into or through those walls, that those currently unrated walls will not be required to be made into rated walls ... due to your work.

Please let me know what you find out.
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Re: Existing Dormitory Corridor wall rating requirement

New postby shahin on Tue Sep 13, 2016 12:14 pm

Jerry Peck - Codeman wrote:
shahin wrote:Constructed in 1963, 4 story, type I, Fully Automatic Sprinklered, Uniform Building Code
Corridor walls are not rated at the present time.
The current scope is to:
a)- Add circuits to rooms.
b)- Increase panel sizes.
c)- Increase transformer sizes.
d)- Changing lighting to LED.

Am I required to rate corridor walls, which will be very difficult and expensive to do.


Ah, now I am on the same page you are:
a) - Only if required by your Existing Building code (if there is an Existing Building code), in the last 10 to 15 years these are adopted using the ICC Existing Buildings code as their base code, then local amendments are made to the base code.
b) - Or only if required by a Property Maintenance code (similar in adoption to the an Existing Buildings code over the last 10 to 15 years except based on ICC Property Maintenance code).
c) - Only if required by the Fire Marshal (possible if they use a Fire Prevention code with such a requirement).
d) - All of the above typically base their upgrade requirements on structural changes or changes to walls/horizontal assemblies which are now required to be rated ... typically ... such upgrades are not required for electrical, mechanical, plumbing (MEP) upgrades unless done at the same time as structural changes or changes to walls/horizontal assemblies.
e) - There may be requirements based on the total value of the work versus the before-work appraised value of the structure/building in that if the total value of the work exceeds 50% of the value of the structure (before the work is done), then, yes, it is quite possible that the ENTIRE STRUCTURE may be required to be brought to the code as applicable for new construction (current code).

If only your electrical work is being done, the value of the work likely does not meet the 50% threshold. However, if you are doing that much work, it is likely that other work is also being performed, and the total value of all work would likely be used to calculate the 50% threshold.

Keep in mind that some AHJ track the work for 1 year to 10 year periods, or whatever time periods they elect to use ... and some do not even apply a time period, they simply take each work at its own value. There is no consistency in how this is addressed across the country, or even how it is addressed within one state, and sometimes not even addressed the same throughout one county.

With so many variables in play between all the possible codes, local amendments to those codes, the Fire Marshal, the value of the work ... the only specific answer to your question can come from your local AHJ and/or Fire Marshal.

I suspect that their answer will be that if no work is being done on those walls, other than you possibly making penetrations into or through those walls, that those currently unrated walls will not be required to be made into rated walls ... due to your work.

Please let me know what you find out.


Thanks for your help and I will let you know what happens.
shahin
 
Posts: 3
Joined: Thu Sep 08, 2016 4:48 pm


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