Siding Problems in Salem: Symptoms, Causes & Fixes

Most siding problems announce themselves in one of a handful of ways: wood that has gone soft, boards that have swollen, paint that will not stay on, stains where water has been running, panels that have moved, or holes. The same symptom can have more than one cause, so the table below lists the most likely one first. Every row links to a guide that goes further.

Symptom, likely cause and usual fix

What you notice	Most likely cause	Usual fix	Read next
Boards, trim or window sills feel soft, crumble when probed, or have split and darkened	Dry rot: wood kept wet by failed caulk or paint, trim with no drip cap, or boards too close to soil or a roof	Replace the rotted wood and fix how the water got in; Salem lists dry rot repair among work needing a permit, so check with the city first	Dry rot in siding and trim
Lap boards swollen, flared or soft along the lower edge; paint keeps failing on them	Hardboard (often sold as Masonite) or LP Inner-Seal OSB siding soaking up water at edges and nail holes	Replace the damaged boards if only a few have failed; re-side if it runs across several walls	Swelling hardboard or OSB siding
Grooved plywood panels peeling apart in layers or soft at the bottom edge	T1-11 wetting at its cut bottom edge, unflashed horizontal seams and window corners	Replace sheets or the whole wall; a permit applies where the panels are also the structural sheathing	T1-11 siding damage
Stains, bubbling paint or soft spots below a roof edge, or under windows and doors	Water behind the siding: no kickout flashing, a torn water-resistive barrier, or windows never flashed	Open the area, repair wet wood, and add or fix the flashing	Siding repair
Vinyl panels wavy, buckled, cracked, or slipped out of their trim	Panels nailed too tight or cut without expansion gaps, reflected sunlight, or an impact	Rehang or replace the affected panels	Vinyl siding
Paint blistering and peeling on the same wood boards after every repaint	Moisture pushing the paint off from behind, or cut ends and new boards left unprimed	Find the moisture source, prime every cut end, then repaint	Siding repair
Round holes, alone or in rows, in cedar or other wood siding	Woodpeckers	Patch small holes in sound wood; replace riddled or soft boards	Cedar and wood siding
Green film, black specks or moss on the wall	Mildew, algae or moss on a wall that stays damp, often shaded or under eaves	Gentle cleaning within the siding maker’s limits, then check the wood under heavy growth	Cleaning mildew, algae and moss
Cracks, dents or holes after a storm or a falling limb	Impact damage	Replace the damaged boards or panels; check the barrier behind them	Storm damage and insurance

Soft or crumbling wood

Soft wood is the symptom to take most seriously, because it means the wood has been wet long enough for decay fungi to grow. Probe around the soft spot with a screwdriver: if it meets solid wood a short way off, the damage may stop at the board or the trim piece. If the siding flexes when pushed, or the inside of the same wall is stained, the sheathing may be involved. That distinction decides the price, and the city’s permit rules apply to rot repair as well as to sheathing work. Dry rot in siding and trim walks through the checks, and what causes dry rot explains why wood has to be soaked, not merely damp, before it rots.

Swollen lower edges

When the bottom edge of lap siding has flared, mushroomed or gone soft, and the rest of the board looks fine, the siding is usually a wood-fiber product rather than solid wood. Hardboard and OSB lap siding were widely used in the 1980s and 1990s, and the median home in Salem was built in 1980 (Census ACS 2020-2024), so this is a common find here. Swollen boards do not shrink back, and the class-action settlements for both products closed long ago. Swelling hardboard or OSB siding covers how to confirm what you have and how to choose between replacing boards and re-siding. What siding do I have? helps if you are not sure.

Peeling T1-11 panels

T1-11 is grooved plywood sold in large sheets, and it fails from its edges: the bottom edge near the ground, the horizontal seams between sheets, and the corners of openings. The question that shapes the job is whether the panels are fastened straight to the studs, making them the wall’s structural sheathing as well as its siding. In Salem that version needs a permit to replace. T1-11 siding damage shows how to check.

Stains and bubbling paint under roof edges and windows

Sound siding rarely leaks through its face. Water gets in at details, and a survey of leaking wood-frame buildings in coastal British Columbia found the large majority of problems at windows, deck edges and other interfaces, as what causes dry rot describes. On a house, look first where a lower roof ends against a wall. Oregon’s residential code requires kickout flashing there (section R703.4 of the 2023 Oregon Residential Specialty Code), and a water-resistive barrier over the whole wall (R703.2). Staining below one of those corners is a reason to have the flashing checked. The fix is a siding repair that includes the flashing, not only new boards.

Buckled or cracked vinyl

Vinyl moves with temperature, so it is hung loosely: the Vinyl Siding Institute’s manual calls for about 1/32 inch between the nail head and the panel, and a 1/4-inch gap at corner posts and channels. Panels fastened tight, or cut short of those gaps, can buckle on a hot day, and Salem reached 117°F on June 28, 2021. Sunlight reflected from nearby windows can distort panels too. The vinyl siding page covers repairs and matching faded panels.

Paint that keeps peeling

Paint that fails on the same boards year after year is being pushed off, usually by moisture coming from behind, or it went onto cut ends and replacement boards that were never primed. Scraping and repainting without finding the source tends to fail in the same spot. On a house built before 1978, old paint may contain lead: in Oregon, work that disturbs 20 square feet or more of painted exterior on such a house needs a contractor with a Construction Contractors Board lead-based paint renovation license, so do not sand or scrape large areas yourself. Whether a tired wall needs paint or new siding is weighed board by board in paint or replace siding on a Salem house.

Holes in wood siding

Woodpecker holes let rain into the wall. Small holes in sound wood can be patched and painted; boards with clusters of holes or soft wood around them are better replaced. Woodpeckers are protected under federal law, so the answer is repair and deterrence. Cedar and wood siding covers repairing shingles and lap boards piece by piece.

Mildew, algae and moss

Growth on siding marks a wall that stays damp: shaded walls, walls behind shrubs, and surfaces under eaves. Mildew itself does not decay wood, and sound paint with mildew on it needs washing, not repainting. The risk is what the dampness does to wood trim and the lowest boards over time. How to clean mildew, algae and moss off siding covers the bleach test that tells mildew from dirt, what each siding maker allows, and where Salem lets wash water go.

When a problem becomes a permit job

In Salem, repairing or replacing siding on its own does not need a building permit unless the wall must be fire-resistive. Repairing or replacing the sheathing does, and so does replacing T1-11 that is also the structural sheathing. The city’s permit page also lists “Dry rot repair” among work that always needs a permit, without saying how small a repair that covers, so ask the city before rot work starts. The owner is responsible for making sure required permits are obtained. Salem’s siding permit rules explains both lists; Keizer and Silverton have their own offices.

Repair or replace?

Repair while the damage is contained and the boards can be matched. Price a siding replacement alongside the repair when the same failure shows on several walls, when rot reaches the sheathing in more than one place, or when the product is no longer made. The siding cost page lists published repair and replacement figures with their sources.

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