Siding problems

The dangerous failures are quiet. Siding is designed to let some water past and drain it back out. When flashing is missing at windows, decks, or roof-to-wall intersections, that water goes into the sheathing instead. By the time you see a stain inside or a soft spot outside, the damage has usually been running for seasons.

Buckling or wavy vinyl is almost always an installation fault, not a product fault. Vinyl expands and contracts a lot with temperature; it has to be hung loosely with nails centered in the slots. Nailed tight, it buckles the first hot week. That is a warranty-and-workmanship conversation, not a replacement conversation.

Peeling paint, mold streaks, or wet insulation on inside walls in the same location as an exterior detail — a window head, a deck ledger, a chimney — is a flashing failure until proven otherwise. Have someone open the wall at that spot. Do not accept caulking as the fix; caulk is a maintenance item, not a water management system.

How to choose

Soft or spongy spots

Press the wall. Give means the sheathing behind is wet or rotten. Stop shopping for siding and get the wall opened at that point first.

Buckling or waviness

Usually siding nailed too tight. If it's within the installer's workmanship warranty period, that's their fix, not yours.

Cracked or holed panels

Impact damage. Spot repair is legitimate; expect a color mismatch because sun fading can't be matched with new stock.

Green or black streaking

Often algae, common on shaded north walls, and mostly cosmetic. Streaking below a specific joint or window is different — that's a leak path.

Pest entry and woodpecker holes

Any hole is a water path. Patch promptly, and check whether pests are attracted by rot that's already there.

Pre-1978 homes

If painted surfaces will be disturbed, the EPA RRP rule requires a lead-safe certified firm. Verify certification before anyone starts cutting.