Ultra high density, petrochemical grade cementitious fireproofing

Product Information

MONOKOTE® Z-156PC petrochemical grade cementitious fireproofing has been developed by GCP Applied Technologies to meet the harsh conditions found in petrochemical processing and refinery facilities.

Z-156PC is a Portland cement-based fireproofing requiring only the addition of water at the job site to form a consistent pumpable and trowelable slurry.

Z-156PC is supported by GCP fireproofing representatives worldwide trained in the specification and application of fireproofing products in commercial, industrial and petrochemical environments. GCP has over 40 years experience in the fireproofing business.

Features & Benefits

  • Fire tested—Z-156PC has been tested in accordance with Underwriters Laboratories Inc. UL 1709 and UL 263 (ASTM E119), investigated by UL for exterior use, jet fire tested in accordance with HSE standard OTI 95 634, and blast performance tested to a charge corresponding to 500 lbs of TNT at a standoff of 62 ft.
  • Durability—Z-156PC sets and dries to a hard, damage resistant coating offering resistance against physical contact and impact occurring during routine operations and maintenance at the facility. Z-146PC has been tested for bond, compressive strength, hard-ness and other properties in accordance with API Guidelines Publication 2218) and ASTM in-place performance standards.
  • Application versatility—Z-156PC can be mixed in standard plaster mixers. After mixing, Z-156PC may be spray-applied with commonly available pumping and spraying equipment for high-speed efficient application. For hand application it is recommended that Z-156PC be sprayed into a suitable container and troweled into place as required.
  • Economical—Z-156PC offers cost-effective fire resistance in interior environments such as control rooms and storage facilities as well as in exterior environments such as vessel skirts, pipe racks and other structural supports. Simple mixing and high-speed efficient application reduces both time on site and labor costs.

Conditions not Recommended

  • Use on aluminum or other non-ferrous surfaces.
  • Use as a refractory cement.

Coatings Requirement

  • Steel coatings—Z-156PC neither prevents nor promotes the corrosion of steel. However, the inclusion of calcium nitrite as a corrosion inhibitor has been shown to retard the rate of corrosion due to salt and other aggressive environmental conditions.
    All structural steel surfaces to receive fireproofing should be considered “exposed” to the environment. Where the fireproofing will be exposed to moisture or water, it is recommended that the steel be protected from corrosion with an alkali resistant, immersion grade epoxy compatible with Portland cement.
    The National Association of Corrosion Engineers (NACE) has specific recommendations for the protection of structural steel coated with cementitious fireproofing exposed to petrochemical environments. Contact your coatings supplier for a list of recommended coatings.
  • Surface coatings—Breathable coatings, such as latex paints, may be applied over Z-156PC to achieve various desired aesthetic finishes. However, coatings tend to trap moisture and may require significant maintenance.S

Delivery & Storage

All material to be used for fireproofing shall be delivered in original unopened packages bearing the name of the manufacturer, the brand and proper UL labels for fire hazard and fire resistance classifications. The material shall be kept dry until ready for use. Packages of material shall be kept off the ground, under cover and away from sweating walls and other damp surfaces. All material that has been exposed to water before use shall be discarded. Stock of material is to be rotated and used before its expiration date.

Performance Characteristics

Physical Properties Recommended Specification Laboratory Tested* Values Test Method **
Dry density, minimum average Min. 50 pcf (800 kg/m3) See note below*** ASTM E605
Bond strength Min. 10,000 psf (478 kN/m2) 20,680 psf (990 kPa) ASTM E736
Compression, 10% deformation 850 psi (5.86 MPa) 874 psi (6.03 MPa) ASTM E761
Air erosion Max 0.000 g/ft2 (0.00 g/m2) 0.000 g/ft2 (0.00 g/m2) ASTM E859
High velocity air erosion No continued erosion after 4 hours No continued erosion after 4 hours ASTM E859
Hardness 40 91 ASTM D2240
Bond impact No cracking, spalling or delamination No cracking, spalling or delamination ASTM E760
Deflection No cracking, spalling or delamination No cracking, spalling or delamination ASTM E759
Resistance to mold growth No growth after 28 days No growth after 28 days ASTM G21
Surface burning characteristics Flame spread = 0 Smoke developed = 0 Flame spread = 0 Smoke developed = 0 ASTM E84
Combustibility Less than 5 MJ/m2 total,
20 kw/m2 peak heat release
Less than 5 MJ/m2 total,
20 kw/m2 peak heat release
ASTM E1354

* Independent laboratory tested value. Report available upon request.
** ASTM International test methods modified for Bond Strength and Compressive Strength, where required, for high density, high performance products.
*** All in-place performance tests should be conducted at or below the minimum recommended specification density.


Prior to the application of Z-156PC, an inspection shall be made to determine that all substrates are acceptable to receive fireproofing. Substrates must be free of any substances that would impair the adhesion of the fireproofing. All substrates shall be compatible with Portland cement-based fireproofing. It is recommended that all substrates covered by fire-proofing be routinely inspected as part of an ongoing facilities maintenance program. Where materials have been removed for inspection, GCP should be consulted for proper patching procedures.


Z-156PC shall be mixed by machine in a conventional paddle type or continuous mixer designed for cementitious fireproofing. The mixer shall be kept clean and free of all previously mixed material. The mixer speed shall be adjusted to the lowest speed which gives adequate blending of the material and a mixer density of 65–70 pcf (1040–1120 kg/m3). Using a suitable metering device and mixer, approximately 3 gal (11 L) per bag shall be first added to the mixer as the blades turn. Add Z-156PC and mix until the mix is lump-free with a creamy texture. Overmixing Z-156PC will reduce pumping rate and density.


  • Z-156PC material shall not be used if it contains partially set, frozen or caked material.
  • Z-156PC shall have a minimum average dry, in-place density of 40 pcf (640 kg/m3).
  • Z-156PC can be sprayed directly to lathed steel substrates in one or more passes. A spray gun with a properly sized orifice with spray shield, and air pressure at the nozzle of approximately 20 psi (140 kN/m2) will provide the correct hangability, density and appearance.
  • Z-156PC may also be first sprayed into a suitable container and then trowel applied.


The substrate temperature shall be a minimum of 40°F (4.5°C) f at least 1-hour prior to the application of the MONOKOTE®. Additionally, the air and substrate temperature during application and for a minimum or 72 hours after application shall be no less than 40°F dry naturally.


Z-156PC is slippery when wet. Signs reading SLIPPERY WHEN WET” should be posted in all areas in contact with wet fireproofing material. Anti-slip surfaces should be used on all working surfaces.

A Material Safety Data Sheet for MONOKOTE® Z-156PC is available on our web site at or call toll free at 866-333-3SBM. | North America customer service: 1-877-4AD-MIX (1-877-423-6491)

We hope the information here will be helpful. It is based on data and knowledge considered to be true and accurate, and is offered for consideration, investigation and verification by the user, but we do not warrant the results to be obtained. Please read all statements, recommendations, and suggestions in conjunction with our conditions of sale, which apply to all goods supplied by us. No statement, recommendation, or suggestion is intended for any use that would infringe any patent, copyright, or other third party right. 

MONOKOTE is a trademark, which may be registered in the United States and/or other countries, of GCP Applied Technologies Inc. This trademark list has been compiled using available published information as of the publication date and may not accurately reflect current trademark ownership or status. 

© Copyright 2018 GCP Applied Technologies Inc. All rights reserved

GCP Applied Technologies Inc., 2325 Lakeview Parkway, Suite 450, Alpharetta, GA 30009, USA
GCP Canada, Inc., 294 Clements Road, West, Ajax, Ontario, Canada L1S 3C6.
This document is only current as of the last updated date stated below and is valid only for use in the Canada. It is important that you always refer to the currently available information at the URL below to provide the most current product information at the time of use. Additional literature such as Contractor Manuals, Technical Bulletins, Detail Drawings and detailing recommendations and other relevant documents are also available on Information found on other websites must not be relied upon, as they may not be up-to-date or applicable to the conditions in your location and we do not accept any responsibility for their content. If there are any conflicts or if you need more information, please contact GCP Customer Service.

Last Updated: 2023-06-29