Lynden Window Board & Batten Siding for Sumas Homes
Sumas sits at the far northern edge of Whatcom County, tucked against the Canadian border in the flat farmland of the Nooksack valley. It's a quieter, more agricultural setting than the towns closer to the water, but the underlying weather pattern is the same one that shapes exterior work across this whole corner of Washington: driving rain that comes in sideways more often than it falls straight down, marine air that carries salt inland even this far from open water, and a moss season that can run most of the year on shaded, north-facing walls. Board and batten has become a popular choice for Sumas homes — the vertical lines suit both the area's farmhouse-style properties and newer builds — but it's a profile with more seams than standard lap siding, and in a climate this consistently wet, how those seams are built matters as much as which product goes up.
Lynden Window Co installs James Hardie fiber cement board and batten exclusively for Sumas homeowners. We're a window company at our core, which means we spend every day thinking about how a wall assembly sheds water at its seams and openings — and a board and batten wall, with its face boards, battens, and the window and door openings that interrupt them, asks exactly that question over and over across every elevation.
What Sumas's Climate Asks of a Board & Batten Wall
Driving Rain Against Vertical Seams
Storms moving through this part of Whatcom County rarely drop rain straight down. Wind pushes it sideways into whatever vertical surface is in its path, and a board and batten wall — with battens running the full height of the wall over every seam — gives that wind-driven rain a lot of joint length to test. A batten that's caulked tight instead of properly lapped, or face-nailed without the clearance the material needs to move, becomes a place where water gets pulled toward the fastener line instead of running off the wall.
Marine Air That Reaches the Border Valley
Sumas is well inland from open water, and it's easy to assume that means salt exposure isn't a factor here. It still is. Marine air moves up the valley from the Salish Sea and settles over this whole part of Whatcom County, and over years it works on exposed fasteners, flashing, and lower-grade hardware just as surely as it does closer to the coast — just more slowly. Board and batten uses more fasteners per square foot than lap siding, since both boards and battens need to be secured, so getting fastener corrosion resistance right carries more weight on this profile than on most others.
A Long Moss Season on Shaded Walls
Mild temperatures and sustained regional dampness give moss and mildew a season that stretches across most of the year on walls that stay shaded or tree-covered, and a lot of properties around Sumas have exactly that kind of tree line or north-facing exposure. A batten set tight against a board with no room to breathe traps moisture right where it can't dry, which is a slow, quiet path toward staining, softened substrate, and paint failure right at the seam — usually starting on the walls a homeowner checks least often.
Why Product Choice Matters More on This Profile
Board and batten multiplies whatever weaknesses a siding material already has, simply because there are more seams and more exposed edge per square foot than a standard lap profile. That's a real part of why we don't offer LP SmartSide, vinyl, Cemplank, Allura, primed spruce, or cedar board and batten. Those are legitimate products, and other contractors install them competently — but on a profile with this many joints, in a climate this consistently wet, we made the call to build our entire board and batten offering around one system we trust without reservation.
| Material | Behavior at Batten Seams | Maintenance in This Climate | Realistic Lifespan |
|---|---|---|---|
| James Hardie fiber cement | Dimensionally stable; doesn't swell or cup at the joint | Low; factory finish resists moss and fading | 30+ years with proper install |
| LP SmartSide (engineered wood) | More sensitive to moisture at cut edges and fastener holes | Moderate; edge sealing needs regular upkeep | 15-25 years, climate-dependent |
| Vinyl | Can gap or warp at battens with temperature swings; seams less rigid | Low, but hidden moisture problems are hard to catch | 20-30 years, variable |
| Cedar | Absorbs moisture at every seam without consistent sealing | High; recurring repainting or resealing cycle | 15-25 years with consistent upkeep |
Fiber cement's core doesn't expand and contract with moisture the way wood-based products do, which is precisely the property that matters most on a profile built entirely from vertical seams. James Hardie's factory-applied ColorPlus finish also means the cut edges we prime on site are the exception rather than the rule, unlike field-painted materials where every board face depends on how well site-applied paint holds up outdoors year after year.
What a Correct Board & Batten Install Actually Involves
The finished look of board and batten is simple — vertical boards, battens covering the seams — but a correct install has more happening behind that surface than most other siding profiles:
- House wrap or weather-resistive barrier installed and lapped correctly before any siding goes up
- A drainage gap or rainscreen behind the siding so moisture that gets past the surface can dry out instead of sitting against the wall
- Corrosion-resistant fasteners at the manufacturer's specified spacing, not just enough to hold the boards up
- Battens set with the clearance James Hardie's install spec calls for, not caulked tight, so the wall can shed water instead of trapping it
- Properly flashed, lapped transitions at windows, doors, corners, and the base of the wall, where board and batten's vertical run meets a horizontal surface
- Factory-cured ColorPlus finish preserved by cutting boards face-down and priming any field-cut edges before they go up
Skip any one of these and the wall can still look right for a year or two. The problems that follow — staining at seams, soft spots near the base, paint failure along battens — take a few wet seasons to surface, which is exactly why a corner-cutting install can get away with it right up until the homeowner is the one dealing with the consequences.
Where Board & Batten Meets Your Windows
Because Lynden Window Co works from the window outward, we pay particular attention to a detail that's easy for a siding-only crew to treat as an afterthought: how board and batten terminates at a window or door opening. Every window is a break in the wall's vertical run, which means flashing has to integrate correctly with both the boards and the battens around it, not just the boards. Get that transition wrong and it doesn't show up as a leak on install day — it shows up two or three winters later, as staining or soft trim below a window that looked perfectly fine when the crew packed up.
We build board and batten details around the windows already in place, or around new windows going in as part of the same project, so the flashing at each opening is planned as one continuous system rather than two trades handing off a rough opening and hoping the details line up. For a Sumas home dealing with sustained wind-driven rain, that's one of the more consequential details in the whole job.
Our Process for a Sumas Board & Batten Project
Walkthrough and Assessment
We start by walking the specific walls involved — which face the weather most directly, which stay shaded and slow to dry, and whether the existing wall assembly already has moisture issues that need addressing before new siding goes up. Board and batten installed over a wall with hidden rot just buries the same problem under new material.
Detailing the Plan Before Install Day
We work out batten spacing, corner details, and window and door transitions before crews start cutting material. On a profile with this many seams, settling those details on paper first avoids the kind of field improvisation that's usually where corners get cut.
Installation to Manufacturer Spec
Every fastener, gap, and flashing lap follows James Hardie's published installation requirements for this climate zone, not a generic national standard. That's what keeps the manufacturer's warranty intact, and it's what keeps the wall performing the way it's supposed to for decades rather than years.
Final Walkthrough
We walk the finished job with you, cover what little maintenance board and batten actually needs, and make sure you know what a healthy wall looks like if you ever want to check it yourself.
Why Hire a Crew That Already Works Sumas
Board and batten rewards local, repeated experience in a way a lot of siding profiles don't, because its failure points are subtle and slow to show themselves. A crew that's installed this profile across Sumas and the surrounding border valley through multiple wet seasons already knows which wall orientations need extra attention because of shade and tree cover, how much batten clearance actually holds up in a climate this damp versus what a generic install guide assumes, and where a rainscreen gap earns its keep. That kind of judgment doesn't show up on a spec sheet. It's the difference between a board and batten wall that still looks and performs the same in fifteen years and one that's showing seam staining by year five.
Cost Factors for Board & Batten in This Area
Board and batten typically runs more per square foot than standard lap siding, mainly because of the added material — battens on top of boards — and the extra labor involved in fastening and detailing two layers instead of one. Beyond the base material, a few things move the price on a given Sumas home:
| Factor | Why It Matters |
|---|---|
| Wall height and complexity | More corners, dormers, and transitions mean more cuts and flashing details |
| Existing wall condition | Rot or moisture damage found during tear-off needs repair before new siding goes up |
| Batten spacing and reveal | Tighter spacing uses more material and more fastening labor |
| Window and door count | More openings mean more flashing and finish work at each transition |
| Access and site conditions | Rural lots and outbuildings can add labor time getting equipment and material into place |
We'll walk your specific home and give you real numbers rather than a rough estimate based on square footage alone — two houses of the same size can have very different board and batten costs depending on how many of these factors come into play.
Getting It Right the First Time
Board and batten isn't a forgiving profile to redo. Because the battens cover the seams between boards, correcting a bad install usually means pulling battens, boards, or both, rather than a simple patch job. That's why we treat the planning and detailing phase as seriously as the install itself — the cost of getting it right the first time is a lot lower than the cost of tearing out a wall that went up wrong.
If you're weighing board and batten for a home in Sumas, we're happy to walk the property, talk through what your specific walls and window openings need given their exposure, and give you a straightforward, no-pressure estimate. There's a form below — reach out and we'll set up a time to take a look.