Siding Replacement in Portland, Oregon: Full Re-Side Guide

Siding replacement in Portland, Oregon means taking the old cladding off down to the sheathing and rebuilding the wall’s weather layers before any new siding goes on. The siding is the part you see; the house wrap, window flashing and drainage gap behind it are what keep a Portland winter out of the framing. A replacement quote that only prices boards is pricing half the job.

Portland Siding Pros does not replace siding. Tell us about the house and we pass the job to an independent siding contractor who works in your area, who inspects and quotes directly.

When does replacing beat repairing?

A full re-side makes sense when the problem is the siding itself rather than one bad spot. The usual triggers on Portland-area houses:

• A product that fails everywhere at once. Hardboard lap siding and LP Inner-Seal OSB swell from the edges; T1-11 plywood delaminates from the bottom up. When every wall shows it, patching buys a few years at best. See hardboard siding failure and T1-11 damage.
• Rot that keeps turning up. If each repair uncovers more soft sheathing, the wall is telling you water has been getting behind the siding for a long time. See water behind siding.
• No weather layers to speak of. Older houses were often sided with little or no house wrap and no drainage gap. That can only be corrected with the siding off.

If the damage is contained, siding repair costs a fraction of a re-side and is the better first call.

The job, step by step

The sequence below is what a thorough replacement looks like. Use it to check a quote for what is and is not included.

1. Inspection and moisture probing. The contractor checks the siding, trim and any soft sheathing they can reach, and notes the house’s age (pre-1978 means lead-safe rules may apply) and whether it sits in a historic district.
2. Material choice and a written quote. Fiber cement, vinyl, cedar or engineered wood, plus trim, soffit and paint decisions.
3. Permits or review, if any. Needed for fire-rated walls near a property line and for review in historic and conservation districts.
4. Lead-safe setup on pre-1978 houses: ground sheeting, containment and cleanup practices.
5. Tear-off and disposal. The old siding comes off and the sheathing is exposed.
6. Sheathing and framing repair wherever rot is found. Good quotes price this per sheet or per hour, because nobody knows the amount until the wall is open.
7. House wrap and opening flashing. A continuous water-resistive barrier, lapped shingle-fashion, with windows and doors flashed at the sill, sides and head.
8. Drainage gap. Furring strips, a drainage mat or a drainage-type wrap, so water that gets behind the siding can run out.
9. Trim and details: starter strip at the base, corner boards, window casings, and a kickout wherever a roof edge dies into the wall.
10. The new siding, installed with the maker’s clearances to grade, roofing and decks.
11. Soffits and fascia if they are part of the scope.
12. Caulk, paint or finish, cleanup and a walkthrough.

The code layers behind a new Oregon wall

Oregon’s residential code requires a water-resistive barrier behind exterior siding and flashing at windows, doors and roof-to-wall intersections, including a kickout flashing where a roof edge ends against a wall. By default it also requires a drainage space of at least 1/8 inch between the barrier and the siding, with listed exceptions. Houses sided before that requirement often have no gap at all, and a re-side is the one time it can be added. The code is due for a new edition on October 1, 2026; the contractor should be working to whichever edition applies on the date of any permit.

Choosing the new cladding

• Fiber cement. Will not rot or burn, holds paint well, heavy to handle, and sensitive to clearances at grade and roofing.
• Vinyl. Lowest cost per square foot, no painting, but it must hang loosely to move with temperature.
• Cedar. The traditional choice on older Portland houses; it needs a stain or paint cycle kept up.
• Engineered wood (LP SmartSide and similar). Resin-treated wood strand boards, lighter than fiber cement and priced between vinyl and fiber cement. Cut ends and nail heads need sealing per the maker’s instructions.

Pre-1978 houses and lead-safe work

Paint on a house built before 1978 may contain lead. Oregon draws the line at 20 square feet of disturbed exterior paint: past it, the work belongs to a contractor holding the CCB’s lead-based paint renovation license, using lead-safe methods. Stripping a whole wall is far past it, so ask for that license number as well as the main CCB number. Houses in Portland’s historic districts are nearly all in this group.

Deciding on trim, soffit and fascia

Rotten window trim, corner boards and fascia are common finds during a Portland tear-off. Decide up front whether they are in the quote, and whether the contractor is pricing replacement in the same material or in fiber cement or PVC trim, which does not rot.

Portland siding replacement prices

The cost table further down this page comes from dated, cited sources. The regional averages are for a 1,250-square-foot wall area with trim; the per-square-foot rows are installed prices for each material. The siding cost page explains what moves a job up or down, and the contractor’s quote is the only number that applies to your house.