Can CPVC be Run Exposed?

3/31/2023

With the use of CPVC, what are the limits to how much can be exposed?

I had thought that we needed to have all of the pipe concealed, and I can't see in code how this is addressed.

We have a project with a temperature-controlled and insulated attic (the mechanical engineer has confirmed it will be kept above 40 degrees F year-round) in a warm climate. This is in an NFPA 13R apartment building.

Is CPVC allowed to be run exposed through the combustible attic space?

The attic is not sprinkler protected (NFPA 13R system, 3-story, apartments, smaller-sized project). Thanks in advance.

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13 Comments

Chad

3/31/2023 07:32:35 am

Sadly/Ugly, it can be exposed in some cases as long as its in line with the installation manual. Viking/Blazemaster says:

Exposed Installations Listed hangers are required for all exposed installations. Viking Plastics BlazeMaster® CPVC fire sprinkler products are UL and C-UL Listed for installation by a qualified installer or contractor without protection (exposed) with the following restrictions: (I wont post it all here)

/https://www.vikinggroupinc.com/sites/default/files/documents/080712.pdf'

Each brand will have its own separate instructions.

Anthony

3/31/2023 08:20:24 am

CPVC 100% can be run in combustible concealed space (how else can you install it?)

Darin

3/31/2023 09:16:10 am

I’m with you. Nearly every single installation is “exposed” in an attic. Not sure if the original question means exposed as in an occupied space, e.g. along the underside of a smooth ceiling.

Randy Kimbro

3/31/2023 08:32:03 am

We just ran into this problem (we are an AHJ). Blazemaster, if exposed, must be run next to a smooth finish, horizontal surface. Otherwise it must be protected. Their reasoning is that the CPVC might fail prior to the sprinkler head activating or may fail during activation.

Call the BlazeMaster tech support number. (216-447-5330 [email protected]) They were extremely helpful in explaining and later validating what we were requiring. Since we are an AHJ, we did not have installation experience. We observed some things that did not appear correct and each time a call to BlazeMaster helped us understand and then explain the issue to the installation contractor.

Dan Wilder

3/31/2023 08:40:49 am

It depends...which MFG and what their specific listings are.

Spears allows exposed in attics and basements when other criteria are met (based on sprinkler used, spacing and distance below ceilings, and construction). Blazemaster allows exposed as well with similar requirements. Both have very specific conditions as to when its allowed to be run exposed.

As to specifically within an attic space, is the space considered a combustible concealed space or just an attic? This also changes criteria but many times the CPVC needs to be "tented" (insulation placed over the top of the CPVC).

Use your MFG recommendations, it's not in NFPA, this is a listing criteria allowance.

https://www.spears.com/flameguard.htm
https://www.blazemastertraining.com/

3/31/2023 10:06:36 am

This is a warm-climate, insulated attic that's supposed to stay above 40-degrees.

We run CPVC in non-sprinklered combustible floor/ceiling spaces all the time, so I guess this isn't that far of a departure from that situation.

However, it's just a large open combustible attic. No storage, no occupancy. It just 'feels' a little different because we have the warm/insulated attic which is unusual for me. A fire up there in a large non-sprinklered space would compromise the pipe, but I guess that's not any different than a fire in a combustible concealed space also compromising the pipe.

NFPA 13R gets me in a twist sometimes on ideology, but I get that it's not trying to be an NFPA 13 system.

Jesse

3/31/2023 09:06:33 am

CPVC can indeed be exposed. We get that a lot, where someone heard it from someone, who heard it from someone, who heard it from someone that it can't, but no one knows where in the code it says that.

Each manufacturer handles it differently as far as how much is exposed, using what hangers, and under what circumstances.

Randy Kimbro

3/31/2023 09:35:02 am

Here is the exact wording from the Viking BlazeMaster installation manual:

Combustible Concealed Installations
Viking Plastics BlazeMaster® CPVC fire sprinkler products CANNOT be installed exposed in spaces defined by NFPA 13 as combustible concealed areas requiring sprinklers.

Exception: In accordance with the UL Listing, specially Listed sprinklers exist that have been tested and are Listed for use with Viking Plastics products in combustible concealed spaces requiring sprinklers.

Standard Coverage Sprinklers
These installations shall be below a smooth, flat, horizontal ceiling construction and require the use of Viking Plastics approved one-step cement. The use of listed hangers for thermoplastic sprinkler piping mounted directly to the ceiling (or wall) is permitted. The resulting clearance between the pipe and ceiling (or wall) resulting from the use of the listed hanger is acceptable.

Residential
These installations shall be below a smooth, flat, horizontal ceiling construction, are limited to the unobstructed construction, require the use of Schedule 80 fittings for sizes 1-1/2 inches and greater, and require the use of Viking Plastics approved one-step solvent cement.

There are a lot more details in the manual.

sean

3/31/2023 11:39:47 am

Yes follow mfg requirements

Todd E Wyatt

4/1/2023 07:15:27 pm

If the building meets the (3) requirements for use of NFPA 13R (versus NFPA 13) per the scoping Code ... “2021 IBC 903.3.1.2 NFPA 13R Sprinkler Systems” is shown below in REFERENCES ... then NFPA 13R is the applicable “referenced standard.”

If the attic meets the exceptions per “2021 IBC 903.3.1.2.3 Attics”, automatic sprinkler system (ASPS) protection of the attic is NOT required.

(Based on the building being an “apartment” and 3-stories, it would be classified as a Group R-2 Residential Occupancy Classification (OC) per 2021 IBC Chapter 3 Occupancy Classification and Use. The Type of Const is not known.)

If the Chlorinated polyvinyl chloride (CPVC) pipe meets the requirements of “2022 NFPA 13R Chapter 5 System Components, 5.2 Aboveground Piping and Equipment, 5.2.3” (see REFERENCES), then the intended installation is compliant.

Todd E Wyatt

4/1/2023 07:15:50 pm

REFERENCES
2021 IBC
Chapter 9 Fire Protection and Life Safety Systems
903.3 Installation Requirements
903.3.1.2 NFPA 13R Sprinkler Systems
Automatic sprinkler systems in Group R occupancies shall be permitted to be installed throughout in accordance with NFPA 13R where the Group R occupancy meets all of the following conditions:
1. Four stories or fewer above grade plane.
2. The floor level of the highest story is 30 feet (9144 mm) or less above the lowest level of fire department vehicle access.
3. The floor level of the lowest story is 30 feet (9144 mm) or less below the lowest level of fire department vehicle access.
The number of stories of Group R occupancies constructed in accordance with Sections 510.2 and 510.4 shall be measured from grade plane.

903.3.1.2.3 Attics
Attic protection shall be provided as follows:
1. Attics that are used or intended for living purposes or storage shall be protected by an automatic sprinkler system.
2. Where fuel-fired equipment is installed in an unsprinklered attic, not fewer than one quick-response intermediate temperature sprinkler shall be installed above the equipment.
3. Where located in a building of Type III, Type IV or Type V construction designed in accordance with Section 510.2 or 510.4, attics not required by Item 1 to have sprinklers shall comply with one of the following if the roof assembly is located more than 55 feet (16 764 mm) above the lowest level of fire department vehicle access needed to meet the provisions in Section 503.
4.1. Provide automatic sprinkler system protection.
4.2. Construct the attic using noncombustible materials.
4.3. Construct the attic using fire-retardant-treated wood complying with Section 2303.2.
4.4. Fill the attic with noncombustible insulation.
The height of the roof assembly shall be determined by measuring the distance from the lowest required fire vehicle access road surface adjacent to the building to the eave of the highest pitched roof, the intersection of the highest roof to the exterior wall, or the top of the highest parapet, whichever yields the greatest distance. For the purpose of this measurement, required fire vehicle access roads shall include only those roads that are necessary for compliance with Section 503 of the International Fire Code:
4. Group R-4, Condition 2 occupancy attics not required by Item 1 to have sprinklers shall comply with one of the following:
4.1. Provide automatic sprinkler system protection.
4.2. Provide a heat detection system throughout the attic that is arranged to activate the building fire alarm system.
4.3. Construct the attic using noncombustible materials.
4.4. Construct the attic using fire-retardant-treated wood complying with Section 2303.2.
4.5. Fill the attic with noncombustible insulation.

Todd E Wyatt

4/1/2023 07:16:28 pm

REFERENCES
2022 NFPA 13R
Chapter 5 System Components
5.2 Aboveground Piping and Equipment.
5.2.1
Pipe or tube used in sprinkler systems shall be of the materials specified in Table 5.2.1 or in accordance with 5.2.2.
Table 5.2.1 Pipe or Tube Materials and Dimensions
Materials and Dimensions / Standard
Chlorinated poly(vinyl chloride) (CPVC) plastic pipe (SDR–PR) / ASTM F442/F442M

5.2.3*
Chlorinated polyvinyl chloride (CPVC) pipe shall comply with the portions of the American Society for Testing and Materials (ASTM) standards specified in Table 5.2.1 that apply to fire protection service.
A.5.2.3
CPVC is a plastic material, and consideration is necessary when other materials or chemicals come in contact with CPVC that can cause degradation of performance of the pipe due to interaction of materials. Other construction materials include, but are not limited to, materials used in the fabrication of the sprinkler system, additives to water supplies, cable and wiring, and certain insecticides and fungicides. Compliance with 5.2.3 combined with following the manufacturer’s guidance on installation and compatible materials will help prevent premature performance degradation of nonmetallic piping. Mechanical stress caused by hanging methods or bending on nonmetallic piping beyond the manufacturer’s recommended limitations can cause stress failure over time and should be avoided.
5.2.3.1
Nonmetallic pipe in accordance with Table 5.2.1 shall be investigated for suitability in automatic sprinkler installations and listed for this service.
5.2.3.1.1
Listed nonmetallic pipe shall be installed in accordance with its listing limitations, including installation instructions.
5.2.3.1.2
Manufacturer’s installation instructions shall include its listing limitations.
5.2.3.2
When nonmetallic pipe is used in systems utilizing steel pipe internally coated with corrosion inhibitors, the steel pipe coating shall be listed for compatibility with the nonmetallic pipe materials.
5.2.3.3
When nonmetallic pipe is used in systems utilizing steel pipe that is not internally coated with corrosion inhibitors, no additional evaluations shall be required.
5.2.3.4*
When nonmetallic pipe is used in systems utilizing steel pipe, cutting oils and lubricants used for fabrication of the steel piping shall be compatible with the nonmetallic pipe materials in accordance with 5.1.2.2.
A.5.2.3.4
When fabricating steel pipe for a combination (CPVC–steel) system, the cutting oil and lubricants can cause performance degradation of the CPVC piping. Cutting oils and lubricants found to be compatible are available and should be used.
5.2.3.5
Fire-stopping materials intended for use on nonmetallic piping penetrations shall be compatible with the nonmetallic pipe materials in accordance with 5.1.2.2.
5.2.3.6
Nonmetallic pipe shall not be listed for portions of an occupancy classification.
5.2.3.7
Where pipe other than steel is run horizontally or vertically through wood or metal studs, the following provisions shall apply:
(1) Steel shield plates shall be provided where the face of the piping is less than 1.25 in. (32 mm) from the nearest edge of the member.
(2) Steel shield plates shall have a minimum thickness of 0.0575 in. (1.463 mm) (No. 16 gauge).
(3) Steel shield plates shall cover the area of the pipe where the member is notched or bored.

5.2.9
Fittings used in sprinkler systems shall meet or exceed the standards in Table 5.2.9 or be in accordance with 5.2.12.
Table 5.2.9 Fittings Materials and Dimensions
Materials and Dimensions / Standard
CPVC:
Threaded chlorinated poly(vinyl chloride) (CPVC) plastic pipe fittings, Schedule 80 / ASTM F437
Socket-type chlorinated poly(vinyl chloride) (CPVC) plastic pipe fittings, Schedule 40 / ASTM F438
Socket-type chlorinated poly(vinyl chloride) (CPVC) plastic pipe fittings, Schedule 80 / ASTM F439

Chapter 7 Design Criteria
7.1 Inside Dwelling Unit.
7.1.1 Residential Sprinklers.

7.4 Attics.
7.4.1 Occupied Attics and Attics Used for Storage.
Attics that are intended for occupancy or storage shall comply with Section 7.1, where the attic is part of the dwelling unit, or Section 7.2, where the attic is outside of the dwelling unit.
7.4.1.1
Sprinkler temperature ratings shall comply with 6.2.3.
7.4.2 Fuel-Fired Equipment.
Where fuel-fired equipment is installed in an attic that is not otherwise required to have sprinklers, the space containing the fuel-fired equipment shall comply with 6.6.6.1 through 6.6.6.4.
7.4.3* Other Attics.
Attics that are not required by 7.4.1 to have sprinklers shall be permitted to have protection in accordance with one of the following.
(1) Protection complying with NFPA 13
(2) Protection using sprinklers specifically listed to provide attic protection in residential occupancies using a discharge density of not less than 0.05 gpm/ft2 (2.04 mm/min) and a design area of not less than four sprinklers
A.7.4.3
NFPA 13R does not require installat

James Art, FPE

4/3/2023 09:37:08 pm

Many years ago, in the '70's,
before they came out with the "rated" CPVC,
that melts a bit higher than PVC,
the Palo Alto Fire Dept did some fire sprinkler experiments with Sch. 40 PVC, plain white, like heavy irrigation pipe.

The results were interesting:
If the fire was near a sprinkler, then the sprinkler activated, and the flowing water kept the pipe intact.

If the fire was away from a sprinkler, often the pipe "pinholed" putting some water on or near the fire, and also the flowing water cooled the pipe, but not as well.
After either fire some of the pipe would need to be replaced.
-------------------------------------------------------------------
When I worked for Lawrence Livermore Lab, I discovered they had sprinklered a few of what they called "Trailers" using white PVC pipe.
These buildings were built off site, in 10 foot wide 50 foot long sections, them put together up to 5000 sq. ft. max.
In 1980 a 5.5 magnitude earthquake occurred on the up to them unknown Greenville Fault. Cabinets fell, and the "Trailers" bounced up and down, and off their stands, and broke the supply piping.
Now bookcases are bolted and "Trailers" are secured there.

Can CPVC be Run Exposed?

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