Greenwood Bevel Cedar Repair — HydroGap WRB & Drainage Mat Rainscreen

The problem — paint bubbling and peeling

The owners of this Greenwood bungalow called us because the paint on their bevel cedar siding was bubbling and peeling off in patches, especially around the front wall. From the street it looked like a paint problem. It almost never is. When paint releases from cedar like that, what you are looking at is moisture trying to escape from behind the board with nowhere to go.

What we found at tear-off

Once we pulled the bevel cedar, the cause was obvious. The original wall had no rainscreen — the cedar was nailed directly against the housewrap and sheathing. With no drainage cavity and no airflow, condensation built up between the back of the cedar and the wall. The Tyvek was soaked and stained from years of trapped moisture. In several spots the plywood sheathing had gone soft, and the trim around one of the front windows had rotted through. Up at the eave, water had also been finding its way into the soffit, rotting framing in pockets we could only see once the cladding was off.

This is what happens when cedar siding has no way to dry. The board absorbs moisture from rain and from condensation off the cold sheathing in winter, and because it is pinned flat against the wall it can only release that moisture outward — through the paint film. The paint blisters, the back of the cedar stays wet, and eventually the substrate behind it starts to rot. Dry rot in Seattle siding almost always traces back to a moisture path like this.

What we specified

• Full removal of the front wall cladding down to sheathing, including the failed window trim and any soft plywood.
• Plywood sheathing repairs — cut out and replace rotted sections, sister rotted framing at the window opening and at the soffit pocket.
• Benjamin Obdyke HydroGap drainable WRB — replaces the water-damaged Tyvek with a housewrap that actually moves bulk water out of the wall.
• 1/2″ drainage mat as a continuous rainscreen — gives the back face of the cedar a vented cavity so it can dry in both directions instead of stewing against the wall.
• Reinstalled bevel cedar, back-primed, with proper end-grain priming and stainless fasteners at the right gauge.
• New window head and side trim with kick-out and flashing detail tied back into the WRB.

The install

Order of operations on the wall:

1. Tear off bevel cedar and old housewrap; expose substrate fully.
2. Cut out and patch rotted plywood, sister rotted framing, rebuild the soffit pocket.
3. Install HydroGap drainable WRB shingle-style, taped at seams.
4. Install 1/2″ drainage mat over the WRB — this is the cavity that lets the cedar dry.
5. Reinstall bevel cedar over the drainage mat with stainless fasteners and proper exposure.
6. New window trim with head flashing tied into the WRB above the mat.
7. Caulk, prime exposed faces, ready for the painter.

The drainage mat is the piece most older Seattle homes are missing. A rainscreen does not have to be furring strips and battens to work — a continuous polymer mat behind the cedar gives you the same vented gap that keeps the back of the board dry. We use it on most cedar siding installs for exactly this reason, and we walk through the building science in detail on our rainscreen systems page.

The takeaway

Cedar is a great cladding in the Pacific Northwest, but only if you give it a way to dry. Pinned directly against the sheathing the way this wall was built originally, even the best cedar will fail early — paint blisters first, then the substrate behind it goes. With a HydroGap WRB and a continuous drainage mat in place, the bevel cedar on this Greenwood bungalow now has airflow behind every board. The cladding will live out its full lifespan instead of being a constant repaint and patch.

If your bevel cedar in Seattle is peeling, bubbling, or showing dark stains around the bottom edges, the answer is rarely just more paint — it is a wall that cannot dry. We work as a Seattle siding repair contractor on jobs exactly like this one, and the assessment is free.