Fiber Cement
Portland cement + cellulose fiber + sand — durable mineral siding & sheathing with no asbestos and no PVC.
Toxicity Screening — All Clear
This material screens clear across all seven independent toxicology authorities we use on every project.
Material Type
Cement-Cellulose Composite Board & Siding
Material Description
Modern fiber cement is made from Portland cement, ground silica sand, water, and a small amount of cellulose fiber from sustainable forestry sources. It replaced asbestos cement decades ago — modern products contain zero asbestos. As a mineral composite it is non-combustible (Class A fire rating), rot-resistant, termite-proof, and dimensionally stable across freeze-thaw cycles. The cured product screens clear across our toxicology panel. The main worker-health consideration is silica dust during field cutting; wet-cut or vacuum-shrouded saws control this completely. EBH specifies fiber cement for exterior siding, soffit, and sheathing where rot resistance and fire performance both matter.
Composition & Origin
Health Profile — All Endpoints Clear
Severity scored 0–10 against the same 10 hazard endpoints we use for the chemical families on the avoid list. Every score is 1–2 — essentially no signal across every endpoint.
Common Forms & Brands
- James Hardie HardiePlank & HardiePanel
- Allura Plycem
- Nichiha fiber cement panels
- Common framing: lap siding, panel siding, soffit, backer board, trim
Why We Use It
- Non-combustible Class A fire rating
- Rot and termite-proof
- Dimensionally stable in freeze-thaw climates
- 50+ year manufacturer warranty common
- Cut wet or vacuum-shrouded to control silica dust during install
Where It Performs Best
- Exterior lap and panel siding
- Soffit and fascia
- Tile backer board in wet rooms
- Trim and decorative architectural detail
Building Applications for Fiber Cement
Listed alphabetically. Where in a home this material earns its keep.
Backer Board (Wet Rooms)
Decorative Architectural Trim
Exterior Lap Siding & Cladding
Soffit & Fascia