Installation Guide

Exterior Installation of PermaBASE CI™ Insulated Cement Board

Download the PermaBASE CI™ Insulated Cement Board Installation Guide


Wall Framing: Framing members should be spaced a maximum of 16" o.c. and shall be a minimum of 2"x 4" nominal (wood) or 20 gauge (metal). Edges of PermaBASE CI parallel to framing should be continuously supported. Provide additional blocking when necessary to permit proper PermaBASE CI attachment.

Water Barrier: While PermaBASE CI is unaffected by moisture, a water/air resistive barrier (WRB) must be installed to protect the cavity. The type and specific placement or location of the water barrier will vary based on local building codes and/or manufacturers' specifications, installation guidelines, and warranties. Consult the WRB manufacturer’s recommendations for specific installation guidelines.

PermaBASE CI™ Insulated Cement Board:

PermaBASE CI can be cut using three methods:

1. Score PermaBASE CI from the foam side using a utility knife to score/cut completely through the insulation and into the back of the cement board. The board can then be snapped. Cut through the mesh on the front of the board to complete the cut.

2. PermaBASE CI can be cut to length effectively with a hand saw.

3. While wearing the proper protective equipment such as safety glasses and approved respirator, use a power saw with the appropriate blade to cut through the entire panel. Penetrations can be created in the panel with a drywall saw. Apply PermaBASE CI with ends and edges closely butted, but not forced, together. Stagger end joints in successive courses. Drive fasteners into the field of cement board first, working toward ends and edges. Space fasteners maximum 8" o.c. with perimeter fasteners at least 3/8" and less than 5/8" from ends and edges. Ensure PermaBASE CI is tight to framing. Do not overdrive screws to the point they penetrate the fiberglass mesh in PermaBASE CI.

Joint reinforcement: Trowel bonding material to completely fill the tapered recessed board joints and gaps between each panel. On non-tapered joints, apply a 6" wide, approx. 1/16" thick, coat of bonding material over the entire joint. For all joints, immediately embed 4" alkali-resistant fiberglass mesh tape fully into applied bonding material and allow to cure. The same bonding material should be applied to corners, control joints, trims, or other accessories. Feather bonding material over fasteners to fully conceal.

Control Joints: For exterior installations, consult the finish manufacturer for spacing requirements. For exterior tile applications, control joints should be spaced a maximum of every 12'. If no recommendation is available, allow a maximum of 16 lineal feet between control joints. A control joint must be installed but not limited to the following locations: where expansion joints occur in the framing or building (discontinue all cross-furring members located behind joint); when boards abut dissimilar materials; where framing material changes; at changes of building shape or structural system; at each story separation. Place control joints at corners of window and door openings or follow specifications of the architect. Control joint cavity shall not be filled with coating or other materials.


  • Treat joints with 4 in. wide alkali-resistant fiberglass mesh tape set in a polymer-modified mortar or stucco basecoat
  • Steel framing must be minimum 20-gauge (galvanized) (.0312 in. design thickness) or heavier
  • Do not expose PermaBASE CI to temperatures over 220˚F (105˚C)
  • Do not use PermaBASE CI as a nailing base for other finishes
  • Thin veneer construction can reveal planar irregularities in framing
  • Minor cracking at joints may become visible in the finished exterior surface
  • Exterior finishes applied directly to PermaBASE CI: Reinforcing mesh must be embedded in basecoat (consult exterior finish manufacturer for additional installation requirements)
  • Sheathing selection and installation varies according to the type of wall construction

Advantages of Creating Continuous Insulation with PermaBASE:

  • Provides better thermal comfort, lowers heating and cooling costs, reduces likelihood of trapped moisture.
  • Helps mitigate the loss of heat/air conditioning by insulating the studs.
  • Allows multiple finishes on one substrate.
  • Works in all climates – adaptable to varying regional system requirements.
  • Guarantees 15-year exterior warranty – the industry’s leading warranty.
  • Speeds up your schedule – faster to install than the traditional method.

Continuous Insulation with PermaBASE CI™ Insulated Cement Board

As building codes and building insulation requirements become increasingly stringent, you can count on PermaBASE products to help meet your substrate needs for Continuous Insulation (CI). CI on the exterior envelope helps to eliminate air and moisture leakage as well as reduce thermal bridging, or the heating/cooling loss transmitted through steel studs.

With the introduction of PermaBASE CI, designers and contractors now have a simpler, faster method of achieving continuous insulation. PermaBASE® Cement Board has also been used for years to install the final exterior finish over the exterior insulation in applications including Z-furring channels, batten strips, and direct fastener applications. PermaBASE CI and PermaBASE cement board can be used in all types of construction, including commercial, residential and multi-family.