PERM-A-BARRIER® NPL 10/ NPL 10 LT Data Sheet

Fluid-applied impermeable air and vapor barrier membrane

Product Description

PERM-A-BARRIER® NPL 10/NPL 10 LT is a fluid applied, one component, latex-based membrane that cures to form a resilient, monolithic, fully-bonded elastomeric sheet when applied to construction surfaces. Designed to satisfy the requirements of fire-rated assemblies, PERM-A-BARRIER® NPL 10/NPL 10 LT can be included in a wide variety of NFPA 285 compliant wall designs.

PERM-A-BARRIER® NPL 10/NPL 10 LT membrane is vapor impermeable and provides superior protection against the damaging effects of air and liquid water ingress on building structures. The product creates a solid barrier against air infiltration and exfiltration which minimizes energy loss from the structure and associated moisture related issues. Also impermeable to liquid water, PERM-A-BARRIER® NPL 10/NPL 10 LT acts as a water drainage plane.

Product Advantages

  • Fire resistant—meets NFPA 285 as part of various wall assemblies
  • Plasticizer, Phthalate and Halogen-free—safe and environmentally-friendly
  • Air tight—protects against air passage and associated energy losses. Meets new ASTM E2357 standard as required by IECC 2012
  • Single component—fast and easy application with simple spray equipment
  • Fully bonded—transmits wind loads directly to the substrate
  • Seamless—continuous membrane integrity with no laps
  • Strong adhesion to common construction substrates such as wood, block, concrete, OSB, gypsum sheathing and metal
  • Compatible with PERM-A-BARRIER® Flashing Systems

Principal Applications

Air and vapor barrier for new and remedial commercial applications:

  • Concrete block walls with brick veneer or pre-formed cladding panels
  • Steel or wood stud walls with exterior gypsum sheathing, brick veneer or pre-formed panels, plywood and OSB

System Components



Refer to product label and Safety Data Sheet before use. All users should acquaint themselves with this information prior to working with the material. Carefully read detailed precaution statements on the product labels and SDS before use.

SDSs can be obtained from our web site or by contacting us toll free at 866-333-3SBM (3726).

Surface Preparation

All surfaces must be sound and free from spalled areas, loose aggregate, loose nails or screws, sharp protrusions or other matter that will hinder the adhesion or regularity of the membrane installation. The surface must also be free from frost, dirt, grease, oil or other contaminants. Clean loose dust and dirt from the surface by brushing or wiping with a clean, dry cloth.

Concrete and Other Monolithic Cementitious

Surfaces Surface irregularities greater than 1/4 in. (6 mm) across and/or 1/8 in. (3 mm) in depth should be pre-treated with BITUTHENE® Liquid Membrane or repaired with a lean mortar mix or nonshrinking grout. Remove concrete form lines and any high spots greater than 1/8 in. (3 mm) in height to ensure uniform surface. On highly dusty or porous substrates it may be necessary to apply a scratch coat of PERM-A-BARRIER® NPL 10/NPL 10 LT membrane prior to spraying to full thickness.

Concrete Masonry Units (CMU)

The CMU surface should be smooth and free from projections. Strike all mortar joints full and flush to the face of the concrete block. Fill all voids and holes, particularly at the mortar joints, with a lean mortar mix or nonshrinking grout. Alternatively, a parge coat (typically one part cement to three parts sand) may be used over the entire surface.

Exterior Sheathing Panels

PERM-A-BARRIER® NPL 10/NPL 10 LT membrane may be applied directly to exterior sheathing panels such as glass faced wall boards, exterior drywall, and CMU. To avoid deflection at the panel joints, fasten corners and edges with appropriate screws. Fasteners should be driven flush with the panel surface (not counter sunk) and into the framing system in accordance with the manufacturers recommendations. Completely fill the sheathing joint with PERM-A-BARRIER® Universal Flashing & Sealant and then install a scratch coat (approx. 15-30 mils) of PERM-A-BARRIER® Universal Flashing & Sealant with a margin trowel or similar onto the face of the sheathing approximately 1 in. (25 mm) on each side of the sheathing joint, ensuring the edges are tapered to prevent shadowing of the spray application. Once the sealant is tack free, the PERM-A-BARRIER® NPL 10/NPL 10 LT membrane may be applied.


Detailing should be completed prior to applying the full coverage of PERM-A-BARRIER® NPL 10/NPL 10 LT membrane. The field application should completely cover the detail areas to provide a continuous membrane.

For a complete description and instructions on individual details, consult the separate detail sheets found on our web site.

Transitions to beams, columns, window and doorframes, etc. should be made with a strip of PERM-A-BARRIER® Detail Membrane, PERM-A-BARRIER® Aluminum Flashing or PERM-A-BARRIER® Wall Flashing. Only PERM-A-BARRIER® Wall Flashing can be used for through wall flashing applications or under masonry units. Optimum adhesion will be achieved when the membrane or flashing is lapped onto the cured PERM-A-BARRIER® NPL 10/NPL 10 LT membrane. As soon as the PERM-A-BARRIER® NPL 10 membrane is cured (approximately 24 hrs after application at 50% R.H, 68°F), it is ready to accept self-adhered membranes or flashings.

A minimum 6 in. (150 mm) wide strip of PERM-A-BARRIER® Detail Membrane, PERM-A-BARRIER® Aluminum Flashing or PERM-A-BARRIER® Wall Flashing should be installed and centered over all outside corners ensuring that all horizontal laps shed water. Self-adhered flashing at corners may be installed prior to the PERM-A-BARRIER® NPL 10/NPL 10 LT application in accordance with the applicable data sheet and installation instructions or after PERM-A-BARRIER® NPL 10/NPL 10 LT has cured.

Avoid installing PERM-A-BARRIER® Universal Flashing & Sealant under self-adhered flashing. Best practice would be to install corner flashing prior to detailing exterior sheathing joints with PERM-A-BARRIER® Universal Flashing & Sealant.

Any gaps around penetrations should be grouted solid or caulked with BITUTHENE® Liquid Membrane or a polyurethane sealant prior to the PERM-A-BARRIER® NPL 10/NPL 10 LT membrane application. If applying NPL-10 prior to detailing penetrations, apply NPL-10 up to penetration and then detail with PERM-A-BARRIER® Universal Flashing & Sealant by filling any gaps and overlapping onto the NPL and penetrant 2.5 in (64 mm). Refer to GCP standard penetration details.

Membrane Application

PERM-A-BARRIER® NPL 10/NPL 10 LT membrane can be installed through a spray application. The product may be applied by roller or brush, however spray application is the preferred method. If applying the membrane by roller or brush, multiple material passes may be necessary to ensure that the required wet thickness is achieved. Contact GCP for further details of local applicators, application techniques and spray equipment.

Application Temperature

In spray applications, PERM-A-BARRIER® NPL 10 membrane may be applied at temperatures as low as 40°F (4°C). NPL 10 LT may be applied as low as 25°F (-4C). It is not recommended for use when cold and/or damp conditions exist for prolonged periods. The product is a water-based material. As with all water-based materials, it is subject to freezing at temperatures below 32°F (0°C).

Thickness Control

Application thickness is controlled in vertical applications by marking the area and spot checking the thickness with a wet film thickness gauge. Swipe marks on the surface of the PERM-A-BARRIER® NPL10/NPL 10 LT membrane are acceptable as long as the minimum thickness is maintained.

Coverage Rates

PERM-A-BARRIER® NPL 10/NPL 10 LT membrane is typically applied at a minimum thickness of 70 mils wet. The theoretical coverage rate (not including waste) at a thickness of 70 mils is approximately 23 ft2/gal to reach a 40 mil dry thickness.

Coverage may vary depending on application technique and may be reduced over rough and uneven substrates. The applicator goal should be a continuous membrane at a thickness of 70 mils wet, adjust coverage rate accordingly.


PERM-A-BARRIER® NPL 10/NPL 10 LT membrane is dry to touch and can be overcoated within 4 hours under normal conditions (50% R.H, 68°F). The product dries through in 24 hours at normal conditions (50% R.H, 68°F). Drying and skinning times may vary depending on temperature, humidity and surface conditions.

Application of Insulation and Finishes

PERM-A-BARRIER® NPL 10/NPL 10 LT membrane is not suitable for permanent exposure. Insulation boards may be installed after the product has fully cured. If the insulation cannot be applied within 2 months of the membrane application, some form of temporary protection (such as tarpaulins) should be used to protect the product from the effects of sunlight. Installation of insulation boards can be accomplished by using compatible mechanical fasteners or, solvent free insulation adhesive.


Tools and equipment are most effectively cleaned with using a dish soap mix of 1 oz/per gallon water.(i.e. Dawn® Ultra-2x Active Suds). This method works before material is cured. Mineral Spirits can be used on cured material on tools to remove. Flush system before its used to remove the light oil which was left from factory testing. NPL is a water base product, so soapy water mix to prime pump is best (1-2 gallons). For short shutdown periods, material can remain in equipment and delivery lines. Material should not be left in system for any period of time if temperatures are expected to drop below 40 degrees F (4 C). Normal flushing of system use soapy mix until clear/clean mix is observed (stored at 40 degrees or above).

** Long-term storage, after system has been cleaned with soapy water mix several options can be used. Flushing oil, Graco® - Pump Armor™, Titan™-LS-10 Liquid Shield™ Plus or Mineral Spirits can be pumped through system. Be sure to always pump soapy water mix prior to priming system with NPL.

Note: use proper Safety equipment required and follow all laws/ rules of waste disposal materials.

Storage and Handling

PERM-A-BARRIER® NPL 10/NPL 10 LT membrane should be stored under cover in original sealed containers above 40°F (4°C) and below 100°F (38°C). The shelf life is 12 months in unopened containers. Store opened containers with plastic protective liner covering the material.


PERM-A-BARRIER® NPL 10/NPL 10 LT membrane should not be used in areas where it will be permanently exposed to sunlight, weather or traffic.

Maximum UV exposure period is 3 months in typical conditions.

Do not apply PERM-A-BARRIER® NPL 10/NPL 10 LT membrane in wet weather. PERM-A-BARRIER® NPL 10 should not be applied if rain or temperatures below 40°F (4°C) are expected within 24 hrs. PERM-A-BARRIER® NPL 10 LT should not be applied if rain or temperatures below 25°F (-4°C) are expected within 24 hrs. PERM-A-BARRIER® NPL 10/NPL 10 LT membrane should be kept from freezing as it is subject to freezing at temperatures below 32°F (0°C).

Finished and exposed surfaces should be protected from overspray. PERM-A-BARRIER® NPL 10/NPL 10 LT should be installed over PERM-A-BARRIER® Universal Flashing & Sealant at exterior sheathing panel joints only.

PERM-A-BARRIER® NPL 10/NPL 10 LT membrane should not be used in waterproofing applications or in hydrostatic conditions. This product is not compatible with petroleum solvents, fuels and oils, materials containing creosote, pentachlorophenol or linseed oil.

Physical Properties

Property Typical Value Test Method
Color Grey  
Solids content by volume 53% (48%)  
Density 9.6 lbs./gal (9.37 lbs./gal)  
Drying time @ 50% R.H., 68%1 4 hours - tack free
24 hours - fully dry
Air permeance <0.02 L/s·m2 @ 75 Pa (<0.004 cfm/ft2 @ 1.57 psf) ASTM E2178
Assembly air permeance <0.02 L/s·m2 @ 75 Pa (<0.004 cfm/ft2 @ 1.57 psf) ASTM E2357
Water resistence Pass ASTM E331
Water vapor transmission <1 Perms
<1 Perms
ASTM E96 - Method A
ASTM E96 - Method B
Pull adhesion to glass-mat faced gypsum sheathing2 20 psi ASTM D4541
Pull adhesion to concrete 50 psi ASTM D4541
Elongation 550% ASTM D412 – Die C
Nail sealability Pass ASTM D1970
Low temperature flexibility and crack bridging Pass at -15°F (at -26°C) ASTM C1306
UV exposure period 3 months  

1. Drying and skinning times may vary depending on temperature, humidity and surface conditions.
2. Failure occurs when glass facing pulls away from gypsum core Lab value, field results may vary. | North America Customer Service: +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.

PERM-A-BARRIER and BITUTHENE are trademarks, which may be registered in the United States and/or other countries, of GCP Applied Technologies Inc. Pump Armor is a trademark of Graco, Inc and Liquid Shield is a trademark of Titan Tool. 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. DensGlass Gold is a registered trademark of Georgia-Pacific Corporation.

© Copyright 2018 GCP Applied Technologies Inc. All rights reserved.

GCP Applied Technologies Inc., 2325 Lakeview Parkway, Suite 400, 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 United States. 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: 2023-06-28