Dryvit Backstop NT is a flexible, polymer- based, noncementitious, air/water-resistive barrier, which resists water penetration, eliminates air infiltration, and is vapor permeable. It is classified as a Class III vapor retarder over vertical above grade walls. Questions? Contact Us.
Dryvit Backstop NT is available in three versions:
• Backstop NT – Texture is applied using a trowel, roller, or texture spray equipment.
• Backstop NT – Smooth is applied by roller or texture spray equipment.
• Backstop NT – Spray is applied by airless spray equipment.
Backstop NT – Texture, Smooth and Spray are designed for use with Dryvit EIF Systems as well as other building cladding systems. When used with the Dryvit AquaFlash® System or Dryvit Flashing Tape™, Backstop NT provides an effective air barrier and water-resistive membrane for acceptable substrates.
Working Time: Backstop NT – Texture, Smooth and Spray are noncementitious, water based materials and will not set-up in the pail. Keep pail covered when not in use to minimize skinning.
Drying Time: The drying time is dependent upon the air temperature, wind conditions and relative humidity. Under average drying conditions [70 °F (21 °C), 55% R.H.], Backstop NT will be dry to the touch within 2 hours and cure in 6 hours.
Testing Information: For test data refer to the chart included with this document.
Application Procedure: For complete application instructions, refer to, DS181.
Job Conditions: Air and surface temperature for application of Backstop NT must be from 40 °F (4 °C) minimum to 100 °F (38 °C) maximum and must remain so for a minimum of 12 hours.
Temporary Protection : Shall be provided at all times until membrane is dry and shall not be exposed to weather for longer than 180 days prior to installation of the specified cladding.
All sheathing substrate joints must be treated with Dryvit Grid Tape and Backstop NT – Texture prior to application over the full sheathing surface. Acceptable substrates include:
a. Core treated exterior grade gypsum sheathing meeting ASTM C 1396 (formerly C 79).
b. Core treated exterior grade gypsum sheathing with fiberglass mat facers meeting ASTM C 1177.
c. Exterior fiber reinforced cement or calcium silicate boards.
d. APA Exterior or Exposure 1 Rated Plywood, Grade C-D or better, nominal 1/2 in (12.7 mm) minimum, installed with the C face out.
e. APA Exterior Grade Fire Retardant Treated Plywood, nominal 1/2 in (12.7 mm) minimum, installed with the C face out.
f. APA Exposure 1 Rated OSB, nominal 1/2 in (12.7 mm) minimum. Note: Applications over OSB sheathing requires a minimum of 2 coats of Backstop NT – Smooth or Spray. Backstop NT –Texture is not recommended for the field of wall application over OSB.
g. Unpainted, unsealed concrete and CMU.