Allura Lap Siding - Smooth Texture, 5/16″ x 6¼″ x 12', 5″ Exposure

Allura’s smooth fiber cement lap siding delivers measurable fire safety with a Class A rating and 0 flame spread index at 2.3 lbs per square foot — 30% lighter than some competitors. The product positions itself as an affordable alternative to premium siding brands while offering smooth texture for a modern, clean aesthetic. Contractors should expect transferable 30-year warranty coverage against material defects, rot, termite damage, and hail damage.

Fire Performance and Code Compliance

The Class A fire rating with 0 flame spread index and ≤ 5 smoke developed index makes this critical for Montana’s expanding wildland-urban interface zones. CAL-FIRE WUI Listing (8170-2180:0501 & 0502) provides the documentation commercial projects need. The material meets ASTM C1186 (Type A, Grade II), ASTM C1185, ASTM E136, and CAN/ULC S114 standards.

Additional certifications include Florida Building Code (FL20742-R6, FL38740-R1), Miami-Dade NOA (24-0408-04), and Texas Department of Insurance (EC-16). Testing shows compliance with ASTM E84 and NFPA 285 for assemblies.

Specification	Value	Source
Fire Rating	Class A (NFPA)	manufacturer
Flame Spread Index	0	manufacturer
Smoke Developed Index	≤ 5	manufacturer
Weight	2.3 lbs/sq ft	manufacturer
Compliance	ASTM C1186 Type A Grade II	manufacturer
WUI Listing	CAL-FIRE 8170-2180:0501 & 0502	manufacturer

Installation Requirements

The 1-1/4” minimum overlap per course achieves the 5” exposure. Ground clearance requirements demand minimum 6” from earth and 2” from horizontal hard surfaces like concrete or decks. Maintain minimum 1/8” gap at butt joints with caulk or flashing per local code, plus 1/4” gap to horizontal flashing.

Fastening uses 6-D siding nails for face-fastening or ring-shank roofing nails (1-3/4”) for blind-fastening. Fasten to studs spaced 16” on-center. These specs directly impact warranty coverage — deviation voids protection.

Installation Spec	Requirement
Overlap	1-1/4” minimum per course
Ground Clearance	6” from earth minimum
Hard Surface Clearance	2” from concrete/decks
Butt Joint Gap	1/8” minimum
Horizontal Flashing Gap	1/4”
Stud Spacing	16” on-center
Face Fastening	6-D siding nails
Blind Fastening	1-3/4” ring-shank roofing nails

Weight and Packaging

At 2.3 lbs per square foot, this fiber cement siding weighs less than many competitors. Each 12-foot board covers approximately 5 square feet at 5” exposure. Full packs contain 320-360 boards while micro packs offer 64 boards for smaller jobs.

The product integrates with Allura’s 5/4” and 4/4” reversible trim, soffit, and fascia boards. Color-matched accessories include Allura Spectrum touch-up kits, matching caulking, and standard fiber-cement starter strips.

Bottom Line

This fiber cement lap siding combines Class A fire safety with manageable 2.3 lbs/sq ft weight and 30-year transferable warranty protection. The CAL-FIRE WUI listing makes it defensible for Montana’s wildfire-prone zones. Installation demands precision — 1-1/4” overlaps, 6” ground clearance, 1/8” joint gaps, and 16” stud spacing aren’t suggestions, they’re warranty requirements.

Historical warranty claim difficulties and former Plycem branding concerns show up in contractor feedback, though current 30-year coverage appears comprehensive. The material resists rot, moisture, and pests better than traditional wood siding while requiring less maintenance over time. For contractors prioritizing fire resistance and documented compliance over brand recognition, Allura delivers the certifications commercial projects demand.

FAQ

What actual weight should contractors expect per board? At 2.3 lbs per square foot and 5 square feet coverage per 12-foot board, expect approximately 11.5 lbs per board.

Does the 30-year warranty transfer to new homeowners? Yes, the warranty is transferable, non-prorated, and covers material defects including rot, termite damage, and hail damage.

What’s the difference between face-fastening and blind-fastening options? Face-fastening uses 6-D siding nails visible on the surface. Blind-fastening uses 1-3/4” ring-shank roofing nails hidden under the overlap. Both methods meet warranty requirements when properly executed.

Can this siding handle Montana’s temperature swings? The fiber cement composition (Portland cement, sand, and cellulose fiber) is engineered for freeze-thaw resistance. Reviews indicate it withstands harsh climates including temperature fluctuations, snow, ice, and hail.