Allura Trim 7/16″ - Reversible Cedar/Smooth Board

Allura’s reversible fiber cement trim board offers contractors dual texture options (cedar/smooth) in a single board with Class A fire rating (Flame Spread Index 0) and 15-year warranty. At 7/16 inch thickness, this trim solves the inventory problem contractors face when matching different siding profiles. One side delivers Traditional Cedar texture, flip it over for Smooth finish. CalFire WUI approved (8170-2180:0503) means it passes Montana’s wildfire interface requirements without special ordering.

The Reversible Advantage

Eight nominal widths from 2” to 12” cover every trim application from window casing to corner boards. The reversible design eliminates ordering separate smooth and textured trim boards. Machined square edges deliver clean joints without field modification.

Available in 25 pre-finished colors or ready-to-paint (primed). The Spectrum Color system means contractors can match existing siding or create contrast without waiting for custom orders. Applications include exterior trim for fiber cement lap siding, shakes, and vertical panels; window and door casing; corner boards (inside and outside); soffit transitions and decorative accents.

Specification	Value
Thickness	7/16 in (0.4375 in)
Length	12 ft (144 in)
Fire Rating	Class A (Flame Spread Index 0, Smoke Developed Index < 5)
Combustibility	Non-combustible (per ASTM E136)
Framing Spacing	No greater than 24” on center
Warranty	15-Year Limited

Installation Requirements

Maintain a 1/8” gap between siding and trim for caulking — critical for allowing movement and preventing buckling. Use a circular saw with a diamond blade (PCD teeth) and a dust collection system/HEPA vacuum. Diamond blades aren’t optional. Regular carbide blades generate dangerous silica dust and wear out fast on fiber cement.

Fasten to framing members spaced no greater than 24” on center; use corrosion-resistant (galvanized or stainless) fasteners. Do not caulk nail holes; use Allura Spectrum touch-up paint for cut edges and fastener heads on pre-finished boards. Caulking nail holes traps moisture behind the paint film.

Width Specifications

Nominal Width	Actual Width
4”	3.5 in
6”	5.5 in
8”	7.25 in or 7.5 in
10”	9.25 in
12”	11.25 in

The dual 8” actual widths reflect different production runs. Verify actual dimensions before ordering to ensure consistent reveals.

Frequently Asked Questions

What makes this trim better for Montana’s wildfire zones?

CalFire WUI certification (8170-2180:0503) and non-combustible rating per ASTM E136 meet Montana’s strictest wildfire interface requirements. Class A fire rating with Flame Spread Index 0 exceeds code minimums.

Can you install this trim in direct ground contact?

No. Do not install in direct contact with water-collecting surfaces. Maintain proper clearances from grade, decks, and horizontal surfaces where water pools.

What’s the actual weight compared to wood trim?

Standard fiber cement density; typically ~2.3 lbs/sq ft (estimated). Heavier than wood but lighter than many contractors expect. The 7/16” thickness keeps weight manageable compared to thicker fiber cement options.

Which caulks work with Allura trim?

Compatible caulks include Bostik DUO-SIL Ultra, OSI QUAD MAX, and OSI QUAD. Use polyurethane-based sealants for long-term flexibility with fiber cement movement.