MTI Gravity Cavity Rainscreen Drainage Mat

GRAVITY CAVITY™

ECONOMICAL RAINSCREEN DRAINAGE PLANE

GC 1816, GC 1832

PROTECT YOUR WALLS WITH AN ECONOMICAL SOLUTION

Gravity Cavity™ is the cost-effective alternative to the Sure Cavity® drainage plane. By creating separation between the veneer materials and the structural back-up wall, it effectively drains incidental moisture and promotes drying of the building enclosure. Its 1/8” deep channels outperform mesh-based drainage matrices, ensuring faster moisture removal while resisting compression behind siding.

FEATURES & BENEFITS

• Efficient moisture drainage: True channels direct moisture straight down and out of walls.
• Durable material: High-impact polystyrene resists compression, waviness, and nail drive-through.
• Time-saving installation: Cuts install time in half compared to furring strips and backer board.
• Sustainable design: Made with 96% pre-consumer recycled content.
• Integrated protection: Adhered fabric prevents mortar or stucco from clogging channels and acts as a bug screen.

APPLICATIONS

• Stucco
• Thin stone & thin brick
• Fiber cement & cedar siding
• Brick
• Natural stone

INSTALLATION INSTRUCTIONS

1. Position Gravity Cavity™: Roll out the drainage mat over the WRB on the backup wall with the spunbond fabric facing outward. Back wrap the 4″ fabric on the bottom course to serve as a bug screen.
2. Temporary attachment: Use a hammer stapler for wood backup walls or dabs of adhesive for masonry.
3. Install additional courses: Overlap only the fabric; ensure the plastic butts directly to the course beneath it.
4. Apply veneer: Secure the veneer material, which will permanently hold the Gravity Cavity™ drainage mat in place for thin veneer applications.

SPECIFICATIONS

• Material: High-impact polystyrene sheets.
• Thickness: 0.024" (0.6 mm).
• Fabric skirt: 4" (102 mm) on one edge.
• Design: Corrugated with a spunbond polypropylene fabric for drainage and ventilation.

PACKAGE QUANTITIES

RESOURCES

• Product Specs
• Cut Sheet
• MTI Product Comparison