Glenhaven Siding Two Popular Sidings, Two Very Different Materials
If you've priced out a siding job in Glenhaven, you've probably run into both James Hardie fiber cement and LP SmartSide engineered wood in the same conversation. They get compared constantly because they solve a similar problem — giving homeowners a durable, paintable alternative to vinyl or raw cedar — and because both are backed by real manufacturer engineering rather than a generic big-box product. But the materials themselves are fundamentally different, and that difference matters more here on the Whatcom County coast than it would in a dry inland climate.
We install James Hardie fiber cement exclusively. We don't install LP SmartSide. This page is our attempt to explain that decision honestly — what LP SmartSide does well, where it runs into trouble, and why we've concluded fiber cement is the better long-term bet for homes dealing with salt air, driving rain, and months of moss pressure every year.
What LP SmartSide Actually Is
LP SmartSide is an engineered wood product — strand-based wood fiber (similar in concept to OSB) treated with resin and zinc borate for moisture and insect resistance, then coated with a proprietary sealant called SmartGuard. It comes as lap siding, panels, and trim, and it installs faster and lighter than fiber cement because it's a wood product at its core. Builders like it. It cuts easily, holds a fastener well, and it costs less per square foot than James Hardie in most markets.
Credit where it's due: LP has put real engineering into solving wood siding's historic weak point, which is moisture absorption at the surface. SmartGuard is a legitimate improvement over old-school untreated wood composite siding from decades past. For homeowners in drier parts of the country, LP SmartSide can be a reasonable, budget-conscious choice.
Where the Trouble Starts
The vulnerability isn't the face of the board — it's the edges. Every cut end, every seam, every place a nail or screw penetrates the board is an opening in that factory sealant. Wood strand product exposed to sustained moisture at a cut edge or a fastener hole will swell, and once it swells, it doesn't shrink back to its original shape. That swelling telegraphs through the paint film, and it's the single most common complaint we hear about aging engineered wood siding — bubbling, rippling, or soft spots along butt joints and around windows and doors.
In a place like Glenhaven, where driving rain off the Sound and a long moss season keep exterior surfaces damp for a much bigger share of the year than most of the country, every one of those cut edges and fastener penetrations is under more sustained moisture load. That's not a knock on LP's engineering — it's just physics. Wood strand product wants to absorb water, and our climate offers it more chances to do so.
What James Hardie Fiber Cement Brings to the Table
James Hardie siding is a cement, sand, and cellulose fiber composite — no wood strand, no OSB core. It doesn't swell at cut edges the way engineered wood does, because there's no wood fiber structure to absorb and hold water the same way. That single material difference is the whole reason we standardized on it.
Beyond the base material, Hardie's ColorPlus finish is a factory-baked, multi-coat finish that's more consistent and more fade-resistant than field-applied paint, and it comes with its own separate finish warranty. Hardie also engineers regional product lines — its HZ5 formulation is built specifically for wetter, more humid climates like ours, with moisture and mold resistance tuned for exactly the conditions Whatcom County throws at a house. It's also non-combustible, which matters more every year as wildfire smoke seasons stretch later into the Pacific Northwest calendar.
Fiber Cement Isn't Maintenance-Free
To be fair to LP SmartSide, we won't pretend Hardie siding is a "set it and forget it" product either. It still needs caulking maintained at joints and penetrations, gutters kept clear so water isn't sheeting down the wall, and periodic washing to keep moss and mildew from taking hold in our climate. No siding material — fiber cement, engineered wood, or vinyl — is exempt from regular upkeep here. The difference is what happens when maintenance lapses for a season or two, which is common in real life. Fiber cement tolerates that lapse far better than a wood-based product does.
Side-by-Side Comparison
| Factor | James Hardie Fiber Cement | LP SmartSide |
|---|---|---|
| Core material | Cement, sand, cellulose fiber | Engineered wood strand (OSB-type) |
| Behavior at cut edges/fasteners | Does not swell; edges should still be sealed per spec | Vulnerable to swelling if moisture reaches raw wood fiber |
| Combustibility | Non-combustible | Combustible (wood-based) |
| Factory finish | ColorPlus baked-on finish, separate warranty | SmartGuard factory-primed or prefinished options |
| Climate-specific engineering | HZ5 line built for wet/humid regions | Standard formulation nationwide |
| Installed cost | Higher material and labor cost | Lower material cost, faster install |
| Weight/handling | Heavier, more labor-intensive to install correctly | Lighter, faster to handle and cut |
| Typical warranty | Long-term, transferable manufacturer warranty | Manufacturer warranty, often more exclusions around moisture damage |
Installation Sensitivity Matters for Both — but the Stakes Differ
Neither product performs well if it's installed wrong. Both James Hardie and LP SmartSide require correct clearances above rooflines and decks, proper flashing at windows and doors, correct fastener placement, and sealed cut edges. A rushed or careless installer can shorten the life of either product significantly.
The difference is what a mistake costs you over time. On a fiber cement job, a missed caulk joint is a maintenance item — something to catch on a walkaround and fix. On an engineered wood job, that same missed joint is a moisture entry point into a material that's structurally built from wood fiber, and the damage from a slow leak can go unnoticed for a long time before it shows up as visible swelling or soft siding. We'd rather build in a wider margin for error against a wet climate, not a narrower one — which is a big part of why we don't offer LP SmartSide as an option.
What It Actually Costs
We won't quote you a number here that isn't tied to your specific house, but the honest framing is this: LP SmartSide typically installs for less than James Hardie fiber cement, both in material cost and labor time, because it's lighter and faster to work with. If budget is the only factor, that price gap is real and we're not going to pretend otherwise.
Where the math changes is over a 20-30 year ownership horizon. Fiber cement's resistance to moisture-related edge damage, its factory finish longevity, and its non-combustible rating tend to mean fewer surprise repair costs and a longer service life before a full re-side is needed. For a coastal Whatcom County property taking on more rain and moss exposure than the regional average, that longer runway carries more weight than it might in a drier market.
Why We Standardized on James Hardie for Glenhaven Homes
We made the call to install only James Hardie fiber cement because our jobs sit inside a specific, repeatable set of conditions: salt-laden air off the Sound, driving rain for a large share of the year, and a moss season that runs longer here than in most of the state. Those three conditions together put more sustained moisture and biological growth pressure on an exterior wall than a lot of the country ever deals with. Fiber cement's core resistance to edge swelling, paired with a climate-specific HZ5 formulation and a factory finish built for UV and moisture, matches that reality better than an engineered wood product does.
This isn't a claim that LP SmartSide is a bad product everywhere — it's a legitimate, well-engineered option that plenty of reputable builders use successfully in less demanding climates. It's a statement about what we're willing to put our name behind on a home that has to stand up to a Pacific Northwest coastal winter, year after year, with realistic (not ideal) maintenance.
What to Ask Any Contractor Before You Sign
- What siding material and product line are they quoting, and why do they recommend it for your specific site and exposure?
- Are they a manufacturer-certified installer for that product, and can they show proof?
- What are the manufacturer's minimum clearances above rooflines, decks, and grade — and will the install plan actually meet them?
- How are cut edges, seams, and fastener penetrations going to be sealed?
- What does the warranty cover, is it transferable, and what voids it?
- What's the maintenance schedule they recommend for your climate and exposure — and will they put it in writing?
Let's Talk About Your Home
Every house in Glenhaven sits a little differently — some catch more direct weather off the water, some sit tucked back with more tree cover and moss pressure, some have sun-baked south walls that age differently than the shaded north side. We're happy to walk your property, look at your current siding condition, and give you a straight, no-pressure estimate for a James Hardie fiber cement install built for your specific exposure. Fill out the form below and we'll get you scheduled.