• Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by first logging in then clicking here: Upgrades

Poke thru question

Michael Schirmer

Registered User
Joined
May 16, 2019
Messages
19
Location
dallas
We had a CEU by Legrand yesterday and they mentioned poke-thru outlets are required to be 24 inches CTC from another poke-thru and no more than 1 per 65 square feet. I'm not going to question this. I just want to know where this is in code? I havent received a clear answer from the instructor on the location in code and i was hoping to learn something hear if anyone knows.

Thanks!
 
We had a CEU by Legrand yesterday and they mentioned poke-thru outlets are required to be 24 inches CTC from another poke-thru and no more than 1 per 65 square feet. I'm not going to question this. I just want to know where this is in code? I havent received a clear answer from the instructor on the location in code and i was hoping to learn something hear if anyone knows.

Thanks!



Seems like others agree

 
2018 IBC
714.4.2 Membrane penetrations.
Membrane penetrations shall comply with Section 714.4.1. Where walls or partitions are required to have a fire-resistance rating, recessed fixtures shall be installed such that the required fire resistance will not be reduced.

Exceptions:

1. Membrane penetrations of maximum 2-hour fire-resistance-rated walls and partitions by steel electrical boxes that do not exceed 16 square inches (0.0 103 m2) in area, provided that the aggregate area of the openings through the membrane does not exceed 100 square inches (0.0645 m2) in any 100 square feet (9.29 m2) of wall area. The annular space between the wall membrane and the box shall not exceed 1/8 inch (3.2 mm). Such boxes on opposite sides of the wall or partition shall be separated by one of the following:

1.1. By a horizontal distance of not less than 24 inches (610 mm) where the wall or partition is constructed with individual noncommunicating stud cavities.

1.2. By a horizontal distance of not less than the depth of the wall cavity where the wall cavity is filled with cellulose loose-fill, rockwool or slag mineral wool insulation.

1.3. By solid fireblocking in accordance with Section 718.2.1.

1.4. By protecting both outlet boxes with listed putty pads.

1.5. By other listed materials and methods.

2. Membrane penetrations by listed electrical boxes of any material, provided that such boxes have been tested for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing. The annular space between the wall membrane and the box shall not exceed 1/8 inch (3.2 mm) unless listed otherwise. Such boxes on opposite sides of the wall or partition shall be separated by one of the following:

2.1. By the horizontal distance specified in the listing of the electrical boxes.

2.2. By solid fireblocking in accordance with Section 718.2.1.

2.3. By protecting both boxes with listed putty pads.

2.4. By other listed materials and methods.


3. Membrane penetrations by electrical boxes of any size or type, that have been listed as part of a wall opening protective material system for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing.

4. Membrane penetrations by boxes other than electrical boxes, provided that such penetrating items and the annular space between the wall membrane and the box, are protected by an approved membrane penetration firestop system installed as tested in accordance with ASTM E814 or UL 1479, with a minimum positive pressure differential of 0.01 inch (2.49 Pa) of water, and shall have an F and T rating of not less than the required fire-resistance rating of the wall penetrated and be installed in accordance with their listing.

5. The annular space created by the penetration of an automatic sprinkler, provided that it is covered by a metal escutcheon plate.

6. Membrane penetrations of maximum 2-hour fire-resistance-rated walls and partitions by steel electrical boxes that exceed 16 square inches (0.0 103 m2) in area, or steel electrical boxes of any size having an aggregate area through the membrane exceeding 100 square inches (0.0645 m2) in any 100 square feet (9.29 m2) of wall area, provided that such penetrating items are protected by listed putty pads or other listed materials and methods, and installed in accordance with the listing.
 
2018 IBC
714.4.2 Membrane penetrations.
Membrane penetrations shall comply with Section 714.4.1. Where walls or partitions are required to have a fire-resistance rating, recessed fixtures shall be installed such that the required fire resistance will not be reduced.

Exceptions:

1. Membrane penetrations of maximum 2-hour fire-resistance-rated walls and partitions by steel electrical boxes that do not exceed 16 square inches (0.0 103 m2) in area, provided that the aggregate area of the openings through the membrane does not exceed 100 square inches (0.0645 m2) in any 100 square feet (9.29 m2) of wall area. The annular space between the wall membrane and the box shall not exceed 1/8 inch (3.2 mm). Such boxes on opposite sides of the wall or partition shall be separated by one of the following:

1.1. By a horizontal distance of not less than 24 inches (610 mm) where the wall or partition is constructed with individual noncommunicating stud cavities.

1.2. By a horizontal distance of not less than the depth of the wall cavity where the wall cavity is filled with cellulose loose-fill, rockwool or slag mineral wool insulation.

1.3. By solid fireblocking in accordance with Section 718.2.1.

1.4. By protecting both outlet boxes with listed putty pads.

1.5. By other listed materials and methods.

2. Membrane penetrations by listed electrical boxes of any material, provided that such boxes have been tested for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing. The annular space between the wall membrane and the box shall not exceed 1/8 inch (3.2 mm) unless listed otherwise. Such boxes on opposite sides of the wall or partition shall be separated by one of the following:

2.1. By the horizontal distance specified in the listing of the electrical boxes.

2.2. By solid fireblocking in accordance with Section 718.2.1.

2.3. By protecting both boxes with listed putty pads.

2.4. By other listed materials and methods.


3. Membrane penetrations by electrical boxes of any size or type, that have been listed as part of a wall opening protective material system for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing.

4. Membrane penetrations by boxes other than electrical boxes, provided that such penetrating items and the annular space between the wall membrane and the box, are protected by an approved membrane penetration firestop system installed as tested in accordance with ASTM E814 or UL 1479, with a minimum positive pressure differential of 0.01 inch (2.49 Pa) of water, and shall have an F and T rating of not less than the required fire-resistance rating of the wall penetrated and be installed in accordance with their listing.

5. The annular space created by the penetration of an automatic sprinkler, provided that it is covered by a metal escutcheon plate.

6. Membrane penetrations of maximum 2-hour fire-resistance-rated walls and partitions by steel electrical boxes that exceed 16 square inches (0.0 103 m2) in area, or steel electrical boxes of any size having an aggregate area through the membrane exceeding 100 square inches (0.0645 m2) in any 100 square feet (9.29 m2) of wall area, provided that such penetrating items are protected by listed putty pads or other listed materials and methods, and installed in accordance with the listing.
If i'm reading this correctly, this is only for partitions, not floor slab. Am I wrong on my interpretation?
 
I cannot seem to locate the same requirement in the IBC or NEC.

That said, I have found the same requirement within the manufacturers installation guide for every major brand that I looked at. Seems to be a part of the UL listing.
 
It is also required in the IRC between dwelling units
2018 IRC
R302.4.2 Membrane penetrations.
Membrane penetrations shall comply with Section R302.4.1. Where walls are required to have a fire-resistance rating, recessed fixtures shall be installed so that the required fire-resistance rating will not be reduced.

Exceptions:

1. Membrane penetrations of not more than 2-hour fire-resistance-rated walls and partitions by steel electrical boxes that do not exceed 16 square inches (0.0103 m2) in area provided that the aggregate area of the openings through the membrane does not exceed 100 square inches (0.0645 m2) in any 100 square feet (9.29 m2) of wall area. The annular space between the wall membrane and the box shall not exceed 1/8 inch (3.1 mm). Such boxes on opposite sides of the wall shall be separated by one of the following:

1.1. By a horizontal distance of not less than 24 inches (610 mm) where the wall or partition is constructed with individual noncommunicating stud cavities.

1.2. By a horizontal distance of not less than the depth of the wall cavity where the wall cavity is filled with cellulose loose-fill, rockwool or slag mineral wool insulation.

1.3. By solid fireblocking in accordance with Section R302.11.

1.4. By protecting both boxes with listed putty pads.

1.5. By other listed materials and methods.

2. Membrane penetrations by listed electrical boxes of any materials provided that the boxes have been tested for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing. The annular space between the wall membrane and the box shall not exceed 1/8 inch (3.1 mm) unless listed otherwise. Such boxes on opposite sides of the wall shall be separated by one of the following:

2.1. By the horizontal distance specified in the listing of the electrical boxes.

2.2. By solid fireblocking in accordance with Section R302.11.

2.3. By protecting both boxes with listed putty pads.

2.4. By other listed materials and methods.

3. The annular space created by the penetration of a fire sprinkler provided that it is covered by a metal escutcheon plate.

4. Ceiling membrane penetrations by listed luminaires or by luminaires protected with listed materials that have been tested for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing.
 
It is also required in the IRC between dwelling units
2018 IRC
R302.4.2 Membrane penetrations.
Membrane penetrations shall comply with Section R302.4.1. Where walls are required to have a fire-resistance rating, recessed fixtures shall be installed so that the required fire-resistance rating will not be reduced.

Exceptions:

1. Membrane penetrations of not more than 2-hour fire-resistance-rated walls and partitions by steel electrical boxes that do not exceed 16 square inches (0.0103 m2) in area provided that the aggregate area of the openings through the membrane does not exceed 100 square inches (0.0645 m2) in any 100 square feet (9.29 m2) of wall area. The annular space between the wall membrane and the box shall not exceed 1/8 inch (3.1 mm). Such boxes on opposite sides of the wall shall be separated by one of the following:

1.1. By a horizontal distance of not less than 24 inches (610 mm) where the wall or partition is constructed with individual noncommunicating stud cavities.

1.2. By a horizontal distance of not less than the depth of the wall cavity where the wall cavity is filled with cellulose loose-fill, rockwool or slag mineral wool insulation.

1.3. By solid fireblocking in accordance with Section R302.11.

1.4. By protecting both boxes with listed putty pads.

1.5. By other listed materials and methods.

2. Membrane penetrations by listed electrical boxes of any materials provided that the boxes have been tested for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing. The annular space between the wall membrane and the box shall not exceed 1/8 inch (3.1 mm) unless listed otherwise. Such boxes on opposite sides of the wall shall be separated by one of the following:

2.1. By the horizontal distance specified in the listing of the electrical boxes.

2.2. By solid fireblocking in accordance with Section R302.11.

2.3. By protecting both boxes with listed putty pads.

2.4. By other listed materials and methods.

3. The annular space created by the penetration of a fire sprinkler provided that it is covered by a metal escutcheon plate.

4. Ceiling membrane penetrations by listed luminaires or by luminaires protected with listed materials that have been tested for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing.
I will concede that it is a similar requirement.

That said, the manufacturers of these poke-thru outlets specify the 24" clearance between and max 1 per 65sf irrespective of being installed within a rated floor system.

Beyond that, the penetration resulting from one of these poke-through outlets is intended to provide a floor outlet. In other than structural concrete slabs that provide fire resistance, the typical installation will not penetrate a rated assembly membrane.

As an example, think of a traditional wood framed floor. The box penetrates the floor sheathing, which is not a membrane within the rated assembly.

The ultimate answer needs to be install in accordance with the manufacturers installation instructions and product listing.
 
The ultimate answer needs to be install in accordance with the manufacturers installation instructions and product listing.
And when that is not provided to the inspector on the job site at the time of inspection we defer to the minimum code requirements as adopted.
 
I cannot seem to locate the same requirement in the IBC or NEC.

That said, I have found the same requirement within the manufacturers installation guide for every major brand that I looked at. Seems to be a part of the UL listing.
So this comes down to whether a product will be warrantied.
 
I will concede that it is a similar requirement.

That said, the manufacturers of these poke-thru outlets specify the 24" clearance between and max 1 per 65sf irrespective of being installed within a rated floor system.

Beyond that, the penetration resulting from one of these poke-through outlets is intended to provide a floor outlet. In other than structural concrete slabs that provide fire resistance, the typical installation will not penetrate a rated assembly membrane.

As an example, think of a traditional wood framed floor. The box penetrates the floor sheathing, which is not a membrane within the rated assembly.

The ultimate answer needs to be install in accordance with the manufacturers installation instructions and product listing.
ok, thanks for the explanation here. That helps.
 
And when that is not provided to the inspector on the job site at the time of inspection we defer to the minimum code requirements as adopted.
The work we do is commercial interior design and a lot of jobs under $500k. We make a lot of notes stating, "...refer to manufacturer's requirements." because we don't always know what the sub is actually going to pull unless we specify a specific device to be installed. I'm assuming this works for the sub. So if we were going to quote a Legrand poke-thru, but not necessarily required spec, your saying it is preferred to still see this info on the plans?
 
No... it is still a code violation to not follow the listing.
That's good to know. I haven't dealt with UL, or any other safety performing companies, very much so i had thought it was not a requirement like this. It seems like reasonable expectations, but i know I've seen it in the field where poke-thrus were definitely closer than 2' apart and over the 1 per 65 sq ft. I guess that's why I thought this came down to manufacturing guidelines.
 
Top