Curb Mounted vs Deck Mounted Skylights.

Curb-mounted and deck-mounted skylights differ primarily in how installers mount and attach them to the roof.

Curb-mounted skylights sit atop a raised frame (the curb) built on the roof.

A curb mounted skylight.

Deck-mounted skylights mount directly to the roof deck.

A deck mounted skylight.

Curb-Mounted Skylights:

  • Installation: The skylight installs on top, like a shoebox lid, of a built-in curb frame on the roof. The curb is part of the roof.
  • Ease of Installation: Generally easier to install, particularly for new construction.
  • Cost: Can be a more budget-friendly when replacing the skylight.
  • Appearance: The curb frame can be more noticeable and might not be as aesthetically pleasing for all roof styles.
  • Energy Efficiency: Might have slightly lower energy efficiency than deck-mounted skylights due to the curb’s insulation is typically the thikness of the lumber..
  • Roof Pitch: Suitable for a range of roof pitches, including flat roofs. A curbs is required for roof slopes that are less than 14°.

Deck-Mounted Skylights:

  • Installation: The skylight mounts directly onto the roof deck, often with a self-flashing design.
  • Ease of Installation: Can be more complex to install, especially on existing homes, requiring precise fitting of the opening.
  • Cost: Might be more expensive due to the complex installation and potential for labor costs.
  • Appearance: Provides a more streamlined, low-profile look that blends better with the roofline.
  • Energy Efficiency: Offers better energy efficiency due to their tighter seal and lower curb.
  • Roof Pitch: Generally suited for roof pitches between 14 and 60 degrees.

Summary Table:

FeatureCurb-Mounted SkylightsDeck-Mounted Skylights
InstallationOn a raised, site-built curbDirectly on the roof deck
Appearance More visible, sits higher on the roofLow-profile, blends with the roofline
Roof PitchIdeal for flat or low-pitched roofs (0-60¯)*Suitable for pitched roofs (14-60°)
Energy EfficiencyGenerally less efficientTypically more energy efficient
Installation Higher labor costs for building the curbPotentially lower installation costs

*Curb mounted skylights are required for roof slopes below 14°.