A top-down, slightly angled view of a VELUX FCM 4646 fixed curb mount skylight. The skylight is shown installed on a simulated roof deck, which is a light-colored wood panel. The skylight itself features a dark gray or black frame and clear glass. This skylight comes installed with white, double pleated honeycomb blackout shades.
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46½ x 46½, FCM 4646, Fixed Curb Mount Skylight with Room Darkening Shade

VELUX
SKU:
FCM 4646 2004
$659.00
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VELUX FCM 4646 Fixed Curb Mount Skylight

Transform your space with abundant natural light and enhanced sun protection using the VELUX FCM 4646 Fixed Curb Mount Skylight. This non-venting skylight is an economical solution for visually expanding rooms, and its integrated solar-powered room darkening shade offers effortless light control. Designed for both flat and sloped roofs, it's ideal for replacing existing curb-mounted skylights, including older plastic bubble types.  

Key Features & Benefits:

  • Fixed Skylight Design: Provides ample natural light to visually expand and transform any room.  
  • Integrated Solar-Powered Room Darkening Shade: Offers effortless control over incoming light with a wireless, solar-powered operation, eliminating the need for wiring.  
  • Enhanced Energy Efficiency: The solar-powered shade helps block the sun's heat in summer and retain interior heat in winter, improving the skylight's overall energy efficiency by up to 40%.
  • Tempered LowE340 Sun Protection Glass: Ideal for warm climates and rooms with large window areas, providing a superior indoor climate during summer periods.
  • Room Darkening Shade: Features a white double-pleated blackout cloth with a honeycomb structure and interior aluminum coating to block even the brightest sunlight.  
  • Versatile Curb Mount Design: Suitable for installation on both flat and sloped roofs, making it perfect for replacements.  
  • VELUX 10-Year Installation Warranty: When installed with the appropriate VELUX flashing kit (sold separately) on a pitched roof.  
  • Code Approvals: Holds Florida Product Approval FL13303 and Texas Department of Insurance TDI SK03.

Technical Specifications:

  • Type: Fixed Curb Mount Skylight with Solar Room Darkening Shade  
  • Rough Opening (W" x H"): 49.5" x 49.5" (Outside Curb Dimensions)
  • Roof Pitch: 0 - 60 degrees
  • Shade Included: Yes, Solar Powered Room Darkening Shade
  • Flashing: Requires separate VELUX flashing kit (sold separately)  
  • Installation: Curb Mounted (curb not included)
  • Approvals: Florida Product Approval FL13303, Texas Department of Insurance TDI SK03, ECL 4646 0000C, ECW 4646 0000C, KIG 300, KLR 300

Warranty: (Consult VELUX documentation for specific warranty details on this model.) VELUX offers a 10-year installation warranty when installed with the appropriate VELUX flashing kit (sold separately) on a pitched roof.

 

FCM 4646 Sizing Chart FCM 4646
Inside curb (W"xH") 46 1⁄2 x 46 1⁄2
Outside curb (W"xH") 49 1⁄2 x 49 1⁄2
Maximum skylight clearance (W"xH") 50 5⁄8 x 50 5⁄8

Fixed VELUX Skylight – Durable, Energy-Efficient Natural Light for Any Space

Bring natural light into your home with a VELUX Fixed Skylight—engineered for lasting performance, thermal efficiency, and sleek curb appeal. Designed for use on flat or sloped roofs, VELUX Fixed Skylights are a dependable solution for brightening dark hallways, bathrooms, stairwells, and more, without sacrificing energy performance.

 

Benefits:

• Maximizes daylight without heat gain
• Reduces reliance on artificial lighting
• Increases visual comfort in underlit areas
• Designed to last—backed by the VELUX 10-Year No Leak Warranty

VELUX 10-Year Installation Warranty

VELUX flashing is designed to perfectly integrate with VELUX skylights, creating a weathertight seal that protects your home from leaks and water damage. By using VELUX-certified installers and genuine VELUX flashing, you can be confident that your skylight is installed correctly and to the highest standards.

Flashing

Step Flashing (EDL) – For asphalt shingles, wood shake, and slate roofs (1/2" max thickness).  

High-Profile Flashing (EDW) – For tile roofs over 3/4" thickness. 

Metal Roof Flashing (EDM) – Designed for standing seam and corrugated metal roofing.  

Copper Step Flashing (EDL COPPER) – Premium option for high-end roofing materials.

Roof Pitch

Compatible with low- to steep-slope roofs ranging from 0:12 to 20:12 pitch (0°–60°). Fixed curb mount skylights are ideal for installations where a site-built curb is already in place or required—common in both retrofit and new construction. Suitable for most roofing materials, including asphalt shingles, tile, and metal. Best used when replacing older dome skylights or integrating into commercial and residential projects with existing curbs.

Curb Mount

A curb-mount skylight is designed to install over a raised frame—called a curb—that sits above the roof surface. This type of skylight is ideal for both new construction and retrofit applications, especially when replacing older units. Unlike deck-mounted models, curb-mounted skylights are elevated off the roof deck, allowing for flexible sizing and easier replacement without disturbing the roof structure.