Semiahmoo Why Custer Homes Need a Different Siding Approach
Custer sits close enough to the water and open farmland that homes here take a beating most siding products were never engineered for. You've got salt-laden air drifting in off the Strait, wind-driven rain that finds every gap in a poorly flashed wall, and a wet season that runs long enough to grow moss on anything that stays damp for more than a few days at a time. Add the temperature swings between a cold, damp winter and a dry summer, and you've got a climate that will expose the weak points in any siding product within a handful of years.
We install fiber cement siding on Custer homes specifically because it's built to take that punishment without the maintenance spiral that comes with wood-based products. This page walks through what that actually means for your house, what a correct installation looks like, and how we run the job from first look to final walk-through.
What Salt Air, Rain, and Moss Actually Do to Siding
These aren't abstract concerns — they're the specific failure modes we see on older homes throughout this part of Whatcom County.
Salt Air
Airborne salt accelerates corrosion on exposed fasteners and metal trim, and it settles into porous or unsealed wood surfaces where it holds moisture longer than it otherwise would. Over time that speeds up rot in anything that isn't genuinely water-resistant at the material level, not just at the paint layer.
Driving Rain
Wind off open fields and water pushes rain sideways into wall assemblies, not just straight down. Siding that relies on a tight paint film or a caulk joint to stay watertight will eventually let moisture behind the cladding, and once water gets behind siding, it's the water-resistive barrier and flashing details — not the siding face — that determine whether your sheathing survives.
Moss Season
Extended damp periods let moss and algae establish on any siding surface that holds surface moisture, especially on north-facing walls and under eaves that don't get much sun. Moss traps moisture against the surface, and on products where the surface itself absorbs water, that trapped moisture works its way into the material over time.
Why Fiber Cement Fits This Climate
James Hardie fiber cement is a cement-and-cellulose composite, not a wood product. It doesn't absorb water the way wood or wood-fiber siding does, it won't rot, and it's non-combustible. That combination matters a lot in Custer specifically because it removes the failure mode that drives most of the siding replacements we get called out for: moisture getting into the material itself rather than just sitting on the surface.
Hardie's HZ5 product line is engineered for exactly this kind of climate — cold, wet, humid — and holds up better here than the HZ10 line built for hot, dry regions. Getting that spec right at the ordering stage isn't a minor detail; it's the difference between siding that's matched to Whatcom County weather and siding that technically works but wasn't built for it.
The factory-applied ColorPlus finish also matters more here than in a milder climate. Because it's baked on in a controlled environment rather than field-applied, it holds color and resists the kind of fading and streaking that site-painted or primed siding shows within a few years of salt air and UV exposure.
What a Correct Installation Involves
Fiber cement siding is only as good as the assembly it's installed into. A quality board with a sloppy installation still fails — usually at the flashing, the fastening, or the water-resistive barrier, not at the siding itself. On every Custer job we run through the same non-negotiables:
- A continuous water-resistive barrier installed and lapped correctly, with all penetrations properly flashed before a single board goes up
- Proper flashing at windows, doors, and any horizontal trim to direct water out and away from the wall assembly
- Correct fastener type and placement — face-nailed or blind-nailed per Hardie's spec, into framing, not just sheathing
- Minimum clearance maintained between the bottom of the siding and grade, decks, or roof lines to avoid wicking moisture
- Proper joint treatment and caulking at butt joints and trim, using products rated for the exposure
- Factory-cut or properly sealed field cuts, since an unsealed cut edge is the one place raw fiber cement can take on water
Skip any one of these and you end up with a wall that looks right for a season or two before problems start showing at the seams — which is usually where we get called in to fix another contractor's shortcut.
How We Approach a Custer Siding Job
1. Walk the Home
We look at the whole envelope, not just the siding — current condition, existing flashing, any signs of past water intrusion, and how the house is oriented relative to prevailing wind and rain. North and west-facing walls in Custer typically need extra attention given the moss and driving-rain exposure.
2. Spec the Right Product
We spec HZ5 boards, the right profile for your home's style, and a ColorPlus finish that fits the neighborhood without the added maintenance of field painting down the line.
3. Address What's Underneath
Any compromised sheathing, old flashing, or water-resistive barrier gets addressed before new siding goes up. Covering a wet or damaged wall assembly with new siding just hides the problem — it doesn't solve it.
4. Install to Spec
Fastening, flashing, clearances, and joint treatment follow Hardie's published installation guidelines, which is also what keeps the manufacturer's transferable warranty intact if you ever sell the home.
5. Final Walk-Through
We go over the finished work with you directly, including care and cleaning recommendations specific to this climate.
Fiber Cement vs. Other Siding Options for This Climate
We get asked why we don't offer alternatives like vinyl or wood-based composite siding. Here's the honest comparison for a climate like Custer's:
| Factor | James Hardie Fiber Cement | Vinyl | Wood-Based Composite |
|---|---|---|---|
| Moisture absorption | Does not absorb water into the material | Doesn't absorb, but seams and gaps let water behind panels | Wood fiber content can absorb and swell if the surface is compromised |
| Salt air resistance | Cement composite unaffected by salt | Can become brittle and discolor over time | Exposed edges vulnerable to accelerated deterioration |
| Finish durability | Factory ColorPlus finish, long fade resistance | Color molded in, but fades and chalks over time | Typically factory-primed, needs field painting and upkeep |
| Fire resistance | Non-combustible | Combustible, can melt or warp near heat | Combustible |
| Impact resistance | Strong resistance to hail and debris | Can crack in cold temperatures | Moderate, dependent on product |
Vinyl and composite products both have real advantages elsewhere — vinyl is inexpensive, composite has a warmer look — but for a climate that combines salt exposure, driving rain, and a long moss season, we've standardized on Hardie because it holds up to that specific combination without the ongoing maintenance burden.
What Custer Homeowners Should Watch For on an Existing Home
If you're not sure whether your current siding is due for replacement, these are the signs we look for on a first inspection:
- Persistent moss or algae growth that returns shortly after cleaning
- Soft spots, bubbling, or visible swelling, especially near the bottom courses and around windows
- Paint that's peeling or bubbling in patterns that suggest moisture trapped behind the surface, not just weathering
- Visible gaps or separation at seams, corners, or trim
- A musty smell or visible staining on interior walls that share an exterior wall with problem siding
Any one of these on its own isn't necessarily an emergency, but a few together usually means moisture has already gotten past the siding face.
Why Local Experience on This Product Matters
Fiber cement installation isn't complicated in theory, but getting it right in a climate like this depends on details that only show up with local experience — the right clearance at grade given how wet Custer ground stays through winter, flashing choices that account for wind-driven rain direction, and knowing which orientations on a given lot need extra attention against moss. A crew that installs Hardie regularly in Whatcom County brings that judgment to your job instead of applying a generic install spec that was written for a drier region.
If you're weighing a siding project for your Custer home, we're happy to take a look and walk you through what we'd recommend and why — no pressure, no sales script, just a straight answer based on what we see on your house. Reach out for a free estimate and we'll get you scheduled for a walk-through.