Short answer: in Bellingham, almost always. If you're re-siding a home here and a contractor isn't talking to you about a rainscreen, that's a flag. But "almost always" isn't "literally always," so here's the plain-English version of what a rainscreen is, why our climate makes it matter, and which walls need it most.
What a rainscreen is, plainly.
A rainscreen is a vented air gap behind your siding. Instead of nailing the siding flat to the wall, we fasten vertical furring strips or roll out a drainage mat first, so the siding hangs off the wall with a small continuous gap behind it. That gap, usually a quarter inch to three quarters of an inch, lets water drain out the bottom and lets the wall dry from the back. That's the whole idea. It's simple, and it's the difference-maker here. We break down the cost in the rainscreen cost guide.
Why Bellingham specifically.
We get about 35 inches of rain a year, and we stay damp for long stretches between storms. No siding is perfectly watertight, water always finds its way behind it eventually, through laps, around windows, in wind-driven rain. The thing that matters is whether that water can get back out and whether the wall can dry before the next rain. A rainscreen says yes to both. Direct-applied siding, nailed flat with no gap, says no, and traps the moisture against the sheathing. That's exactly how the old T1-11 and hardboard on so many Bellingham homes rotted the walls behind them.
Which walls need it most.
If you're going to draw a line anywhere, draw it by how well the wall can dry on its own:
- Shaded, damp walls need it most. North-facing walls and homes under heavy tree cover, like a lot of Sudden Valley, Cornwall Park, and Silver Beach homes, barely see the sun. They can't dry from the front, so drying from the back is everything.
- Cedar and wood essentially require it. Real wood won't last in this climate unless it can dry. A rainscreen under cedar is not optional if you want the wood to make it.
- Fiber cement strongly benefits. Hardie performs much better on a rainscreen, and it lines up with how the manufacturer wants it installed.
- Lake and water-facing walls. The humid microclimate near Lake Whatcom and the bay keeps walls damp, so the vented gap earns its keep.
If a Bellingham re-side bid doesn't mention a rainscreen, you're probably looking at a cheaper job that skips the part that makes siding last.
When you might skip it.
There are narrow cases. A small repair to one wall section that's already performing fine, where matching the existing assembly makes more sense than rebuilding it, may not get a full rainscreen. A very protected, well-ventilated wall under a deep overhang dries better than an exposed one. And on a tight-budget vinyl re-side, the case is softer than it is for wood. But these are exceptions. For a full re-side on a Bellingham home, the default answer is yes.
Is it worth the money?
A rainscreen adds $3,500 to $9,000 to a re-side. Set against a $20,000 to $40,000 project, and the sheathing and framing it protects, that's cheap insurance against the exact failure that wrecks siding here. The county's permit reviewers and the WA energy code keep pushing toward better water management for the same reason. It's not an upsell. It's the part of the job that makes the rest of the money worth spending.
For a free walkthrough and a straight answer on your walls, Bellingham Siding Co. installs rainscreen systems on every re-side across Bellingham and Whatcom County.