Wood-Framed Chase Stripped to the Sheathing and Re-Clad

Problem

This chimney is a wood-framed chase, not a masonry stack. It carries a factory-built metal flue and has no mass to shed water on its own, so the cladding and the flashing are the only things keeping weather off the framing inside. One honest note on the record: our photos start after the old covering was already off, so what is documented here is the rebuild, not the failure that called for it.

Diagnosis

With the exterior stripped, the framing and the sheathing were open and could be assessed before anything new went back over them. The rebuild was sequenced from the roof up, because a chase almost always lets water in at the shingle junction long before the panels themselves give out. Flashing went in first and every layer after it was lapped to drain onto the layer below.

Solution

• 01Re-sheathed the exposed chase framing in OSB
• 02Set base and step flashing at the shingle line before any cladding went up
• 03Wrapped the sheathing in Grip-Rite ShingleLayment synthetic underlayment, lapped over the flashing
• 04Fitted grooved siding panels with corner trim, then caulked and primed the seams and fastener heads
• 05Fabricated a metal chase cover, sealed the collar where the flue passes through, and fitted a mesh spark-arrestor cap
• 06Painted the finished chase to match the existing roofline

Outcome

The chase went back together as a layered assembly rather than one skin of siding: flashing under the wrap, wrap under the panels, a sealed cover over the top. Each stage was photographed before the next one buried it, which is the only way anyone can verify later what is actually behind the paint. Two trade-offs worth stating plainly. The field-applied paint is the shortest-lived part of this job, so repainting will come due years before the panels, the wrap, or the flashing need attention. And the existing factory-built flue was reused as found, because re-cladding a chase says nothing about the condition of the flue running up inside it. That is a separate inspection.