Vinyl Siding Inspection

Vinyl siding must be installed loose enough to expand and contract. Nails centered in slots, not driven tight. Panels must overlap properly.

1. Check that panels are loose — should slide 1/4" side to side (thermal expansion requirement)

2. Verify nails are centered in nail slots and not driven tight (1/32" gap between nail head and siding)

3. Check panel overlap — minimum 1" at horizontal joints

4. Verify panels are level — sight along the bottom edges

5. Check J-channel around windows and doors — properly flashed behind

6. Verify starter strip is level at the bottom

7. Check corner posts are plumb and properly overlapping

8. Look for buckling or waviness (indicates nails driven too tight)

- Nails driven tight (siding buckles in heat — most common vinyl siding problem)

- Insufficient overlap at joints

- J-channel not properly flashed (water enters behind)

- Wavy panels from improper nailing

- Starter strip not level

- Panels cut too tight at ends (can't expand)

Vinyl siding is NOT waterproof — it is a rainscreen. House wrap (WRB) behind siding is critical. Proper flashing around all penetrations.

1. Verify house wrap/WRB is installed behind siding (pull up a panel slightly to check)

2. Check flashing at windows — kick-out flashing where roof meets wall

3. Verify utility penetrations (pipes, wires, vents) are sealed

4. Check for proper flashing at transitions (e.g., siding meets stone or brick)

5. Verify bottom is open (not sealed — allows water to drain out)

6. Check that soffit vents are not blocked by siding

7. Inspect for any damaged or missing panels

- No house wrap behind siding (water reaches sheathing — rot and mold)

- Missing flashing at windows (most common siding leak point)

- Sealed bottom edge (traps water behind siding)

- Utility penetrations not sealed

- Missing kick-out flashing at roof-to-wall transitions

- Damaged panels not replaced