MiraTEC trim is a non-structural decorative trim product engineered for exterior applications. It is designed to be applied to structural framing, sheathing, and other materials, offering resistance to moisture, rot, and termites. The product is building code compliant in both the U.S. (ESR-3043 from the ICC-ES) and Canada (CCMC 14015-L from the Canadian Construction Materials Centre). MiraTEC trim is available with either a wood grain texture or a smooth surface and handles similarly to wood. Proper installation techniques, including appropriate fastening and joint treatment, are crucial for optimal performance and aesthetic results.
Material Properties and General Considerations
MiraTEC trim is conceived and engineered to resist moisture, rot, and termites, making it suitable for exterior, non-structural applications. The trim is reversible, featuring a wood grain texture on one side and a smooth surface on the other, allowing for aesthetic flexibility. Installation requires the use of appropriate fasteners and adherence to specific spacing guidelines based on the application. The product is designed to work with wood studs or studs and structural sheathing material.
Fastening Requirements
Correct fastening is critical for the longevity and performance of MiraTEC trim. Nails should have a corrosive resistance equivalent to hot-dipped galvanized nails. In coastal areas, regions with large bodies of water, or high humidity climates, stainless steel fasteners are recommended to prevent rust. Electro-galvanized fasteners are not recommended for these environments due to their limited long-term rust resistance.
For installations utilizing steel studs, ET&F fasteners are specified: AST-075 for 4/4 MiraTEC and AST-100 for 5/4 MiraTEC. Power or pneumatic nailing systems can be used, and air pressure settings for various nailers are available at www.miratectrim.com. Tapered or bugle head fasteners are permissible, provided the heads are properly sealed to prevent moisture intrusion. Staples, brads, or t-nails are not recommended. Nails should be placed at least 1/2 inch from the edge of the trim and should not be driven into the edges themselves.
Specific Application Guidelines
The installation method varies depending on the specific application of the MiraTEC trim. Several common applications are detailed below.
Fascia Installation
For 4/4 and 5/4 fascia and soffit applications, MiraTEC trim can be fastened directly to the rafter ends, double-nailed at a maximum of 24 inches on center. For 5/8 fascia and soffit applications, a sub-fascia is required, and the trim must be nailed 16 inches on center to the rafter ends or sub-fascia. In regions with high or extreme humidity changes, a sub-fascia is recommended even for larger sizes. When mitering for column wraps or corner boards, gluing the edges of the trim is recommended to maintain a tight joint.
Other Horizontal and Vertical Applications
For all other horizontal and vertical applications, double nailing at 16 inches on center, falling on the studs, is required.
Butt Joints
All joints must fall over a framing member. MiraTEC trim can be mitered, scarfed, or beveled as required. Field-cut and raw edges of butt, mitered, scarfed, or beveled joints must be caulked, primed, or painted. For runs less than 30 feet in length, butt joints should lightly touch. For runs exceeding 30 feet, butt and scarf joints should be spaced 1/8 inch apart, with sealant applied to the full depth of the joint. All joints should be double-nailed on both sides.
Finishing and Surface Preparation
Nail heads or any dents can be filled with exterior-grade spackling putty specifically designed for filling nail holes. The putty should be allowed to dry, sanded smooth with 100-grit sandpaper, and spot-primed before painting. Over time, the spackling putty may require replacement or touch-up.
When using the smooth side of MiraTEC trim, additional preparation is necessary. Nails should be set flush or slightly countersunk (not exceeding 1/8 inch). Spackling putty should then be applied as described above, and reapplied as needed to achieve the desired appearance.
Cutting Procedures
MiraTEC trim can be cut using a fine-tooth hand saw or a power saw with a combination blade. Carbide-tipped blades are recommended. Cuts should be made into the exposed face of the material.
Typical Trim Uses
MiraTEC trim is versatile and can be used in a variety of exterior applications, including:
- Fascia: A horizontal board attached below the roof edge.
- Batten: A thin strip used to cover seams between cladding panels or for decorative purposes.
- Garage Door Trim: Exterior trim surrounding garage doors.
- Rake Board or Shingle Mold: A trim board supporting roof shingle overhang and protecting the fascia.
- Frieze Board: A horizontal board covering gaps between the soffit and wall or brick.
- Window Trim: Trim surrounding windows.
Flashing Considerations
When installing MiraTEC trim, continuous horizontal flashing with drip and 2-inch (minimum) overlaps and joints is recommended. This is particularly important to prevent water intrusion and protect the underlying structure.
Conclusion
MiraTEC trim offers a durable and versatile solution for exterior decorative applications. Successful installation relies on adherence to the specified fastening requirements, proper joint treatment, and appropriate surface preparation. Utilizing the correct fasteners, considering environmental factors, and following the guidelines for specific applications will ensure the longevity and aesthetic appeal of the installed trim. The product’s resistance to moisture, rot, and termites, combined with its building code compliance, makes it a reliable choice for a variety of projects.