When it comes to siding a tiny house, you are usually choosing between two giants: Fiber Cement (dominated by James Hardie) and Engineered Wood (dominated by LP SmartSide).
For a standard foundation home, the debate usually centers on price and aesthetics. But for a Tiny House on Wheels (THOW), the conversation changes completely. We have to talk about Weight and Vibration.
This guide breaks down the pros and cons of each material specifically for the mobile tiny house builder.
The Contender: James Hardie (Fiber Cement)
James Hardie “HardiePlank” is the gold standard for residential siding in North America. It is made of cement, sand, and cellulose fibers.
The Pros
- Fire Resistance: This is its superpower. Fiber cement is non-combustible. If you plan to park your tiny house in wildfire-prone areas, this offers immense peace of mind.
- Rot & Insect Proof: Termites can’t eat concrete. It is virtually impervious to rot if installed correctly.
- Aesthetics: It mimics wood grain beautifully and holds paint extremely well (Hardie’s “ColorPlus” technology).
The Cons for Tiny Houses
- Weight (The Dealbreaker?): Fiber cement is heavy. It weighs approximately 2.3 to 2.5 lbs per square foot.
- Brittleness: Cement doesn’t flex. When a tiny house bounces down the highway, fiber cement is prone to cracking, especially around fastener points or corners.
- Difficult Install: You need specialized shears or a diamond-blade saw to cut it (producing silica dust), and it cracks easily if carried improperly.
The Contender: LP SmartSide (Engineered Wood)
LP SmartSide is made of wood strands coated with waxes, resins, and zinc borate (to resist rot/bugs), compressed into a board.
The Pros
- Weight: It is significantly lighter, weighing roughly 1.3 to 1.5 lbs per square foot.
- Durability (Impact): You can hit LP siding with a baseball bat, and it won’t break. This impact resistance makes it excellent for resisting road debris.
- Flexibility: Because it is wood-based, it has a slight flex tolerance, making it handle highway vibrations better than brittle cement.
- Easy Install: It cuts like wood (standard chop saw) and comes in 16-foot lengths (fewer seams) compared to Hardie’s 12-foot lengths.
The Cons for Tiny Houses
- Moisture Sensitivity: While the treated core is rot-resistant, raw cut edges must be primed/painted immediately. If water gets into the core, it can swell.
- Fire Rating: It is wood. While treated to be fire-resistant, it does not have the non-combustible rating of fiber cement.
The Critical Analysis: Weight vs. Longevity
Let’s do the math for a standard 24-foot Tiny House (approx. 500 sq. ft. of siding surface area).
1. The Weight Calculation
- Hardie Plank: 500 sq. ft. x 2.3 lbs = 1,150 lbs
- LP SmartSide: 500 sq. ft. x 1.3 lbs = 650 lbs
The Difference: 500 lbs. In the tiny house world, 500 pounds is massive. That is the equivalent of:
- Your entire fresh water tank (full).
- Or, a washer/dryer combo AND a full solar battery bank.
- Or, your entire personal wardrobe and book collection.
Winner: LP SmartSide (by a landslide).
2. Longevity & Travel
- Hardie: Excellent for stationary longevity (50+ years). However, the risk of developing micro-cracks during transport is higher. If you plan to move often, fiber cement requires very stiff framing.
- LP: Excellent for impact and movement. The zinc borate treatment gives it a 50-year warranty that rivals Hardie, but you must be vigilant about painting cut ends to prevent swelling.
Winner: Tie (LP for mobile frequent movers, Hardie for stationary builds).
The Verdict for Tiny Houses
If you are building a Tiny House on Wheels (THOW) that you intend to move more than once, LP SmartSide is generally the superior choice.
Why?
- You save 500+ lbs of precious Gross Vehicle Weight Rating (GVWR).
- It withstands highway vibration better without cracking.
- It is easier for a DIYer to install without specialized tools.
Choose James Hardie only if:
- You are building on a permanent foundation (not wheels).
- You are in a strict Wildfire Zone requiring non-combustible cladding.
- You have a heavy-duty tri-axle trailer where weight is not a concern.
Comparison Table
| Feature | James Hardie (Fiber Cement) | LP SmartSide (Engineered Wood) |
|---|---|---|
| Weight (per sq. ft.) | ~2.3 lbs (Heavy) | ~1.3 lbs (Light) |
| Material Composition | Cement, Sand, Cellulose | Wood strands, wax, resin, zinc |
| Road Vibration | Prone to cracking | Flexible / Durable |
| Impact Resistance | Low (Brittle) | High (Bounce back) |
| Fire Resistance | Excellent (Non-combustible) | Good (Fire-rated, but combustible) |
| DIY Friendliness | Difficult (Silica dust, heavy) | Easy (Standard wood tools) |
| Typical Warranty | 30 Years (Non-prorated) | 5/50 Years (Prone to exclusions) |