Ravenna Hardie Board & Batten Reside — Hidden Rot Discovery
The problem: siding that looks fine and isn’t
The homeowners called us because they noticed a small amount of water intrusion on the inside of one wall. From the outside, the composite siding looked completely normal — no bowing, no obvious staining, no peeling paint. The kind of exterior a real estate agent would photograph without worrying.
That’s the hardest kind of damage to catch. Composite siding products — especially older formulations that were common on Seattle homes through the 1990s and early 2000s — can absorb moisture slowly from the back side and transfer it into the sheathing and framing without ever showing a problem on the face. By the time you see anything on the inside of the wall, the outside of the wall has already been working against you for years.
We told them what we tell everyone: if there’s water showing up inside, the wall is already telling you something is wrong. The only way to find out how bad is to pull the siding off a section and look.
What we found at tear-off
A rotten corner. Framing that should have been solid 2x structural lumber was soft enough to dig out with a screwdriver. The rot extended several feet from the corner in both directions — far enough that patching wouldn’t have been honest work. We cut the damaged framing out, sistered in new structural lumber, and replaced the sheathing across the affected area before anything else went up.
This is a representative siding replacement Seattle project from our crew. The homeowners in Ravenna called us because they saw water inside the house — a symptom every dry rot repair project starts with. If you’re seeing similar signs on a Seattle-area home, here’s what tear-off usually reveals and how we rebuild.
This is the part of a siding job most homeowners never see — and it’s the part that determines whether the new siding lasts 30 years or repeats the same failure in 10. Every reside is really a two-part job: whatever needs fixing in the wall, and whatever goes on the outside of it.
What we specified
- HydroGap drainable WRB. Standard house wrap is a backup plane only — it sheds water but doesn’t give trapped moisture anywhere to go. HydroGap has molded 1mm spacers integrated into the face, creating a continuous drainage plane between the wrap and the siding. Any water that gets behind the cladding has a dedicated path downhill to daylight.
- James Hardie board & batten. HardiePanel vertical board with HardieTrim battens over the seams — Hardie’s version of the classic board-and-batten look that’s popular in Ravenna and the surrounding Craftsman neighborhoods. Fiber cement rather than composite, so the new cladding won’t repeat the absorb-moisture-from-the-back failure mode that took out the old siding.
- Properly shingled window and door flashing. Head flashing lapped over the WRB, not tucked behind it. Sill pans where the opening detail needed them. Sealant used as a secondary line of defense, never as the primary water stop. These are the details that either keep windows dry for decades or trap water behind them.
Why composite siding can hide damage this badly
Fiber cement like Hardie doesn’t absorb moisture. Cedar absorbs moisture but shows its condition on the face — you can see when cedar is failing. Composite products fall in the middle: they absorb moisture from the back, swell slightly, conduct water into the sheathing behind them, and often maintain a reasonable face appearance the entire time. A homeowner doing an annual walk-around inspection has no way to see the problem until it reaches the inside of the house or until a panel finally gives up.
If you have composite siding on a Seattle-area home that’s more than 15 years old, and especially if you see water stains anywhere inside an exterior wall, we’d rather pull a small inspection panel now and find out than guess. Rot moves slowly for years and then fast for a season. Catching it while it’s localized costs a fraction of what it costs after it’s spread through multiple framing members.
The takeaway
Three lessons from this project that apply to most Seattle-area homes:
- Interior water signs = exterior wall problem. By the time water shows up on the inside, the outside has been compromised for a while. Inspect immediately, don’t watch it.
- The WRB and flashing details matter more than the siding material. We see rot behind every type of cladding — including Hardie installed without proper drainage and flashing. The wall assembly, not the brand name, is what keeps water out.
- Tear-off is your one honest inspection. Everything else is guessing. During a reside, every square foot of sheathing and framing is visible. Don’t close the wall back up without repairing what you find.
Frequently asked questions
How can composite siding hide rot so well?
Many composite products absorb moisture slowly from the back side and conduct it into the sheathing without swelling or discoloring on the face. A homeowner doing a routine exterior inspection has no way to detect the damage. By the time water shows up on the inside of the wall, the framing has often been compromised for years.
What is the difference between board & batten and other Hardie styles?
Board & batten uses wide vertical panels (HardiePanel) with narrow trim strips (HardieTrim battens) covering the seams. It’s the classic style on Craftsman, farmhouse, and Pacific Northwest architecture. HardiePlank is horizontal lap siding; HardieShingle is shake-style. All three use the same underlying fiber cement, but each has its own installation detailing.
How much does dry rot repair typically add to a reside budget?
It depends entirely on extent. Isolated corner rot may add a few hundred to a few thousand dollars. Extensive framing replacement across multiple walls can exceed the cost of the siding itself. We always tear off a sample area first, document what we find with photos, and price the repair transparently before the full project proceeds.
Is HydroGap better than standard house wrap?
For a reside where we’re specifically trying to solve a moisture problem, yes. HydroGap has molded 1mm spacers built into the face that create a continuous drainage plane. Standard Tyvek is a water-shedding membrane only. In a climate with wind-driven rain like Seattle, a drainage WRB significantly extends the life of any cladding that sits over it.
References & manufacturer resources
See water signs inside your walls?
We’ll walk the house, assess what’s likely behind the existing siding, and give you a written assessment before you commit to anything. Catching rot early saves structural framing — and a lot of money.
Request a written assessment