By Dawn Construction. Updated October 2026.
Is James Hardie or LP SmartSide siding better in Washington?
Both work well in Washington when installed right. James Hardie fiber cement is noncombustible and carries a 30-year non-prorated warranty, while LP SmartSide engineered wood is lighter, easier to handle, and covered by a 5/50-year limited warranty that is prorated after year 5. The bigger factor in our rain is the barrier and flashing behind the siding.
The warranty and fire facts come from each manufacturer's own product sheets and warranty pages. The right choice for your home depends on what you value most: fire resistance, weight, finish, or how the warranty is structured.
James Hardie vs LP SmartSide at a glance
| James Hardie (fiber cement) | LP SmartSide (engineered wood) | |
|---|---|---|
| Made of | Cement, sand, and cellulose fiber | Wood strands bonded with resin, treated with zinc borate |
| Siding warranty | 30-year limited, non-prorated | 5/50-year limited: 5 years full coverage, then prorated to 50 |
| Factory finish warranty | ColorPlus: 15-year limited finish warranty | ExpertFinish: 5/15/50-year limited warranty |
| Fire | Noncombustible when tested to ASTM E136 | Wood-based; not classed as noncombustible |
| Pests and hail | Won't attract termites or woodpeckers | Warranty covers fungal decay, termites, and hail up to 1.75 inches |
| Weight | Heavy (Hardie panel siding: about 2.4 lb per sq ft) | Lighter, easier to handle |
| Cutting on site | Produces silica dust; OSHA dust controls apply | Cut like wood |
| Climate version | HZ5 line, engineered for freezing, snow, and ice | No climate-specific version |
How do they handle Washington's rain?
Neither siding is a waterproof wall on its own. Some water always gets behind the boards, so a water-resistive barrier and flashing at every window and door do the real work in our climate.
The warranties make the same point. James Hardie's warranty does not cover water damage, and LP's does not cover swelling. Both companies tie their warranties to proper installation, so the crew matters as much as the brand.
What we do on every siding job, either brand:
- Remove the old siding and repair any rotted sheathing.
- Install a continuous water-resistive barrier, lapped to shed water.
- Flash every window, door, and penetration into that barrier.
- Keep siding clear of soil, paving, and roof surfaces, per the manufacturer.
- Fasten, gap, and finish cut ends exactly as the manufacturer's instructions require.
Which siding has the better warranty?
It depends on how you read the fine print. Hardie's 30-year warranty is non-prorated, meaning coverage doesn't step down over the 30 years. LP's 50-year warranty is longer, but full labor and material coverage lasts 5 years, then coverage is prorated.
| Warranty detail | James Hardie HardiePlank | LP SmartSide |
|---|---|---|
| Length | 30 years | 50 years |
| Structure | Non-prorated | Full coverage for 5 years, then prorated |
| Factory finish | ColorPlus: 15 years against peeling, cracking, and chipping | ExpertFinish: 5/15/50 years |
| Notable coverage | Hail and termite damage | Fungal decay, termites, hail up to 1.75 inches |
| Notable exclusions | Water damage, mold or fungi, improper installation | Swelling, improper storage, misuse |
Always read the current warranty for the exact product you buy.
One detail homeowners often miss: repainting James Hardie ColorPlus siding before its 15-year finish warranty ends voids that finish warranty.
Which siding is safer in a fire?
James Hardie fiber cement is classified as noncombustible when tested to ASTM E136, and its products list a flame spread index of 0. LP SmartSide is a wood product, treated for decay and termites, but it is not a noncombustible material.
If fire resistance is a top priority, especially for homes near wooded areas, fiber cement has the edge.
Which is easier to install and repair?
LP SmartSide is lighter and cuts like wood, so it is easier to carry and handle on site. Fiber cement is heavy; Hardie's panel siding weighs about 2.4 pounds per square foot.
Cutting fiber cement also creates respirable crystalline silica dust. OSHA's construction silica rule lists specific dust controls for saws cutting fiber-cement board. A professional crew plans for this; it is one reason fiber cement is usually not a DIY material.
What about paint and color?
Both brands come primed for painting on site or with a factory finish:
- James Hardie ColorPlus: a baked-on factory finish with a 15-year limited finish warranty.
- LP SmartSide ExpertFinish: a factory finish with a 5/15/50-year limited warranty.
- Primed boards: painted on site in any color, with upkeep that depends on the paint system.
Which siding should you choose?
- Fire resistance matters most: choose James Hardie fiber cement.
- You want the simplest long warranty: Hardie's 30 years non-prorated is easy to understand.
- You want lighter boards and a wood look: choose LP SmartSide.
- You want the longest stated warranty term: LP's 50 years, knowing it is prorated after year 5.
- Either way: the barrier, flashing, and installation decide how long it lasts in our rain.
Replacing siding in the Seattle area: local details
- Permits: Seattle doesn't require a permit to replace siding when no structural changes are made. Other cities may, so check yours.
- Asbestos survey: Puget Sound Clean Air Agency and L&I rules require one before renovation or demolition. Some older siding contains asbestos.
See all materials, including cedar and vinyl, on our siding installation and replacement page.
FAQ
Is LP SmartSide or James Hardie better in the rain?
Both perform well in rainy climates when installed over a proper water-resistive barrier with flashing. Neither warranty covers water damage or swelling from poor installation.
How long is the James Hardie siding warranty?
HardiePlank lap siding has a 30-year non-prorated limited warranty. ColorPlus factory finishes have a separate 15-year limited finish warranty.
How long is the LP SmartSide warranty?
LP SmartSide has a 5/50-year limited warranty: full coverage for 5 years, then prorated coverage up to 50 years. ExpertFinish products carry a 5/15/50-year warranty.
Is fiber cement siding fireproof?
No siding is fireproof, but James Hardie fiber cement is classified as noncombustible when tested to ASTM E136.
Does LP SmartSide get termites?
LP SmartSide is treated with zinc borate to help resist fungal decay and termites, and its warranty covers that damage.
Can I repaint James Hardie ColorPlus siding?
Yes, but repainting before the 15-year ColorPlus finish warranty ends voids that finish warranty.
Which siding is cheaper to install?
It depends on the product line, finish, and house. Fiber cement is heavier and needs dust controls when cut, which affects labor. You get an exact price after a free in-home estimate.
Planning new siding?
Dawn Construction installs James Hardie and LP SmartSide siding across Greater Seattle and the Puget Sound. Book a free estimate and we will help you compare both on your home.
Sources
- James Hardie, HardiePlank lap siding product sheet (warranty, ASTM E136): https://www.gentek.ca/wp-content/uploads/sites/2/2025/04/SS2001_JH_US_Insite_HardiePlank_Form_1223.pdf
- LP Building Solutions, LP SmartSide warranty information: https://lpcorp.com/products/siding-trim/build-with-lp-smartside/warranty-information
- Seattle SDCI, Do You Need a Permit?: https://www.seattle.gov/construction-and-inspections/permits/do-you-need-a-permit