ICON NSL208 & SL2222 RV Skylights — Dome Sizes, Screws & Sealant

Identify ICON NSL208 neo-angle and SL2222 square RV skylight domes by their actual dome and outside-flange dimensions, then select the exact colour-specific manufacturer number. The NSL208 uses a neo-angle footprint, while the SL2222 has a square flange. Compare the original opening, flange and mounting pattern before choosing hardware or sealant.

Two different skylight shapes — dimensions are in inches

Replacement skylight domes by shape and colour

NSL208 — clear, white and smoke

Reference 1 · NSL208

01864 — Clear neo-angle skylight dome

Identification: 20 × 8 in neo-angle; Clear.

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Reference 2 · NSL208

01865 — White neo-angle skylight dome

Identification: 20 × 8 in neo-angle; Translucent white.

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Reference 3 · NSL208

12114 — Smoke neo-angle skylight dome

Identification: 20 × 8 in neo-angle; Smoke.

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SL2222 — clear, white and smoke

Reference 4 · SL2222

01856 — Clear square skylight dome

Identification: 22 × 22 in square; Clear.

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Reference 5 · SL2222

01857 — White square skylight dome

Identification: 22 × 22 in square; Translucent white.

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Reference 6 · SL2222

12121 — Smoke square skylight dome

Identification: 22 × 22 in square; Smoke.

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Installation components — numbered factory products

Reference 7 · Installation hardware

15159 — Skylight mounting screws with gasket washers

Identification: 20-piece screw pack; Stainless steel.

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Reference 8 · Installation sealant

12062 — Self-leveling white skylight sealant

Identification: 10 oz tube; White.

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How the skylight flange, screws and sealant work together

1. Roof opening and support: Verify the shape, original roof curb and sound substrate. The dome size is not the same as the flange's outer dimensions.
2. Exterior dome flange: Select NSL208 or SL2222 based on the complete outline, not colour or nominal opening alone.
3. Under-flange sealant: ICON instructs a substantial bead around the opening before seating the skylight.
4. Gasketed fasteners: Install as instructed without over-tightening or distorting the polycarbonate flange.
5. Exposed fastener sealing: ICON calls for another bead around the flange perimeter and over screwheads.

Follow ICON's installation instructions and the roof manufacturer's sealing requirements. The screw kit and compatible sealant are separate from the replacement dome.

Compatibility checks before ordering

Measure an undamaged portion of the original outer skylight: dome footprint, flange length and width, raised height, angled versus square corners, screw-hole pattern, and whether any interior garnish is also required. Do not treat a 20 × 8 neo-angle and a 22 × 22 square skylight as interchangeable. A clear, white and smoke finish may share a shape within one specified family, but that is not evidence for cross-model substitution.

Interior garnish and inner domes are separate from the exterior skylight. If your roof opening is a different size, compare the 14 × 14 and 22 × 14 skylight guide. The roof-flange sealing guide explains other roof joints, but its sealants should not be substituted for ICON 12062 without manufacturer approval.

Roof safety: Check for hidden wiring and damaged substrate before drilling, avoid stepping on unsupported roof sections, and follow manufacturer instructions for plastic-compatible products. Do not assume that a gasketed screw alone makes a skylight watertight.