Magnolia Vertical Cedar Siding — Rainscreen Over R6 Exterior Insulation

This Magnolia home got a full rebuild of the wall assembly, not just new boards. The owners wanted the warm, modern look of vertical cedar, and they wanted a wall that actually performs in Seattle’s wet climate — warmer, drier, and built to last. So we re-clad it the right way: continuous exterior insulation, a real drainage cavity behind the cedar, and window details flashed to match the new wall thickness. We also repaired and tied into the existing cedar where the new work met the older part of the house.

Windows first — HydroGap WRB, liquid flashing, and a buck-out

The whole assembly only works if water is managed at the openings, so the windows came first. We wrapped the walls in Benjamin Obdyke HydroGap drainable WRB and used a liquid-applied flashing at every window — brushed and tooled into the rough opening so the sill and jambs are sealed as a continuous membrane rather than relying on tape alone.

Because we were adding exterior insulation plus a double rainscreen, the wall was about to get noticeably thicker. To keep the windows in the right plane, we bucked out each opening — building the rough opening proud of the framing so the Marvin windows sit flush with the finished cedar, and the trim and head flashing land where they should.

Continuous exterior insulation — Hunter Panels, R6

Over the WRB we installed Hunter Panels continuous exterior insulation at R6. Putting rigid insulation on the outside of the sheathing is the single biggest performance upgrade you can make to an older Seattle wall: it wraps the studs in a continuous blanket and stops the thermal bridging that lets heat leak straight through the framing. It also keeps the sheathing warmer, which means less condensation inside the wall through our long damp winters.

A double rainscreen for vertical cedar

Vertical boards create a fastening problem: you can’t nail vertical cedar to vertical strapping, and you can’t trap drainage behind it either. The answer is a double, cross-strapped rainscreen. The first layer of furring runs vertically over the insulation to keep an open, continuous drainage and drying path down to the weep at the bottom of the wall. The second layer runs horizontally on top of it — that’s what the vertical cedar actually fastens to.

The result is a true vented cavity behind every board, so the back face of the cedar can dry, while still giving us solid horizontal nailers for the vertical 1×6. This is the same building science behind every cedar job we do — we explain it in detail on our rainscreen systems page.

Installing the vertical 1×6 T&G cedar

With the cavity built, we hung the cladding: 1×6 tongue-and-groove western red cedar, run vertically. T&G locks board to board for a clean, tight reveal, and the vertical orientation gives the house that crisp modern line. Boards are back-vented by the rainscreen, fastened to the horizontal furring, with end grain and cut edges sealed as we went.

Tying into the existing cedar

Not every wall on the house was getting replaced, so part of the job was repairing and matching the existing cedar and making a clean transition where the new vertical work met the older siding at an addition. Tie-ins like this are where a lot of resides look patched — we take the time to line up courses, match the look, and flash the junction so the seam is weatherproof, not just hidden.

Hardie panel soffit with continuous venting

Up at the eaves we ran a James Hardie panel soffit with continuous metal venting. Hardie panel is dimensionally stable and won’t cup or rot the way an unvented wood soffit can, and the continuous metal vent keeps air moving into the attic — which protects the roof deck and the new wall assembly below it. It’s the kind of detail nobody notices until it’s done wrong. (See our James Hardie work for more on the material.)

The takeaway

Cedar is a beautiful cladding for the Pacific Northwest, but it lives or dies on what’s behind it. On this Magnolia home, the vertical 1×6 cedar sits over a continuous drainage cavity, a layer of R6 exterior insulation, and windows flashed and bucked to match — a wall that looks modern and is genuinely warmer and drier than what was there before. That’s the difference between siding that’s installed and siding that’s built.

If you’re weighing vertical cedar, exterior insulation, or a full reside in Seattle, we’d be glad to walk your walls and write you an honest assessment. We work as a Seattle cedar siding contractor on jobs exactly like this one, and the assessment is free.