Semiahmoo Exterior Why Board & Batten Behaves Differently in Custer
Custer sits close enough to Semiahmoo Bay and the Strait of Georgia that homes here deal with a specific combination of weather most siding installers never have to plan for: salt-laden air moving in off the water, long stretches of driving rain, and a moss season that can run from fall through spring. Board and batten siding — with its vertical boards and raised battens covering the seams — is one of the most popular exterior styles in this part of Whatcom County, but the same design that gives it that clean, dimensional look also creates more vertical seams, more batten-to-board joints, and more edges where water and salt residue can find a way in if the material or the install is wrong for the climate.
That doesn't mean board and batten is a bad choice for a Custer home. It means the product and the installation details matter more here than they would in a drier, inland climate. This page covers what we look at specifically for board and batten jobs in Custer, and why we only do this style in one material.
What the Local Climate Actually Does to Board and Batten Siding
Salt Air
Airborne salt from the bay settles on exterior surfaces and accelerates corrosion of fasteners, flashing, and any metal trim. On a board and batten wall, the battens are fastened separately from the boards underneath, which means there are simply more fastener penetrations exposed to that salt exposure over the life of the siding. Fastener choice and flashing details matter more here than on a flat lap siding wall with fewer penetrations.
Driving Rain
Wind-driven rain off the water doesn't just fall — it gets pushed sideways into vertical seams and batten joints. A board and batten wall depends on correct batten spacing, proper caulking at the right joints (and no caulking where it shouldn't be), and a sound water-resistive barrier behind the siding to manage the water that inevitably gets past the surface.
Moss Season
Shaded north- and west-facing walls near tree lines around Custer stay damp for extended periods during the wet months, which is exactly what moss needs to take hold. Moss holding moisture against a wall for weeks at a time is hard on any siding material, but it's especially hard on anything that swells, cups, or absorbs water at the surface.
What a Correct Board & Batten Job Requires Here
Board and batten is not a style you can install the same way everywhere and expect the same result. In Custer's climate, a correct installation involves specific decisions at every stage:
- A continuous, properly lapped water-resistive barrier behind the siding, with all penetrations sealed before the first board goes up
- Correct flashing at every window, door, and roof-to-wall intersection — these are the spots where board and batten failures actually start
- Batten spacing and fastening that accounts for material expansion and contraction through wet winters and dry summers
- Rain-screen or drainage gap detailing so moisture that gets behind the boards can actually drain and dry out, rather than sitting against the wall
- Fasteners rated for coastal, salt-exposed conditions rather than standard interior-grade fasteners
- Factory-finished material wherever possible, so the field isn't relying on site-applied paint or stain to do the waterproofing work
Skip any one of these and the wall might look fine for a year or two. The problems that show up later — staining at the battens, soft spots at the bottom courses, paint failure at the seams — almost always trace back to one of these details being rushed or skipped during the original install.
Why We Only Install James Hardie Board & Batten
We install James Hardie fiber cement exclusively — not vinyl, not engineered wood, not primed spruce or cedar, and not other fiber cement brands. For board and batten specifically, that decision matters more than it might for a flat lap wall, because of how much surface area and how many seams this style exposes to Custer's weather.
Non-Combustible, Dimensionally Stable
Fiber cement doesn't swell, cup, or rot the way wood-based products can when they take on moisture repeatedly through a wet Whatcom County winter. That stability matters at every batten joint, where wood-based boards are most likely to telegraph movement as cracking or gapping over time.
ColorPlus Factory Finish
James Hardie's ColorPlus finish is baked on at the factory under controlled conditions, which gives it better adhesion and UV resistance than most site-applied paint jobs. In a salt air environment, where site-applied finishes tend to break down faster at exposed edges, starting with a factory finish removes one of the weakest links in the system.
HZ5 Engineering for This Region
James Hardie engineers its HZ product lines for specific climate zones, and the HZ5 line is built for the wetter, harsher exposure conditions found throughout the Pacific Northwest coast. That's the line we specify for Custer board and batten work.
Backed by a Real Warranty
James Hardie's transferable limited warranty gives homeowners real recourse on the material itself, which matters on a style with this many joints and this much exposed surface area.
Comparing Board & Batten Material Options for This Climate
| Material | Behavior in Salt Air / Rain | Moss & Moisture Resistance | Finish Longevity |
|---|---|---|---|
| James Hardie Fiber Cement | Non-combustible, dimensionally stable, resists salt-driven corrosion at the panel itself | Doesn't absorb and swell like wood-based products | Factory ColorPlus finish, long repaint interval |
| Vinyl Board & Batten | Can warp or fade under sun/salt exposure cycles; seams rely on overlap, not sealant | Won't rot, but traps moisture behind it if installed tight | Color is through the material but fades and chalks over time |
| Engineered Wood (LP-type) | Vulnerable at cut edges and joints if moisture gets in | Prone to swelling and edge deterioration in prolonged damp conditions | Depends on factory treatment and edge sealing quality |
| Primed Spruce / Cedar | Natural wood movement at every batten joint; needs consistent upkeep | Absorbs moisture, feeds moss and mildew growth if not maintained | Repaint or restain cycle typically every few years |
This is why our crews only carry one material to a board and batten job in Custer. Mixing site conditions this demanding with a product that isn't built for them is how avoidable callbacks happen.
Our Process for a Custer Board & Batten Project
1. On-Site Assessment
We walk the exterior, note which walls take the most weather exposure, check existing flashing and trim condition, and look for any moss or moisture staining that tells us where water has already been getting in.
2. Tear-Off and Sheathing Check
Old siding comes off and we inspect the sheathing underneath before anything new goes up. Water damage found now gets fixed now — not covered over.
3. Water-Resistive Barrier and Flashing
A continuous barrier goes on first, with flashing integrated at every window, door, and roof line before a single board is hung.
4. Board and Batten Installation
Boards and battens go up with fastening and spacing set for this climate, following James Hardie's published installation specifications, not shortcuts.
5. Final Detail Walk
We check caulking, trim, and touch-up paint at cut edges before calling the job done.
Common Problems We Find When Replacing Older Board & Batten Siding
When we tear off older board and batten siding around Custer, the same handful of issues come up repeatedly: battens fastened without any gap for movement, missing or improperly lapped flashing at window heads, moss buildup at the base of walls that stayed damp against untreated wood, and caulk used to try to seal joints that should have had proper flashing instead. These aren't material failures so much as installation shortcuts — which is exactly why the install matters as much as the product.
Maintenance That Actually Matters in This Climate
- Rinse salt residue and pollen buildup off the siding a couple of times a year, especially on walls facing the water
- Keep gutters and downspouts clear so water isn't sheeting down the wall face during heavy rain
- Trim back vegetation and tree cover that keeps shaded walls damp and encourages moss growth
- Treat moss on the siding surface promptly rather than letting it establish and hold moisture against the wall
- Have caulking and trim checked periodically — it's the first thing to break down, well before the siding material itself
Why Hiring a Crew That Already Works Custer Matters
Board and batten siding done wrong doesn't usually fail in year one — it fails in year five or six, after enough wet winters have found every shortcut in the original install. A crew that already works this part of Whatcom County has seen what actually goes wrong on homes exposed to Semiahmoo Bay's salt air and driving rain, and builds the flashing, fastening, and drainage details around that reality instead of a generic install spec. That local track record is worth more than a low bid from a crew installing board and batten the same way regardless of where the house sits.
If you're considering board and batten siding for a Custer home — whether it's a full replacement or you're planning new construction — we're happy to walk the exterior with you and give you a straight, no-pressure estimate using James Hardie fiber cement built for this exact climate.