Common terms you might hear during a skylight estimate, explained plainly.
Acrylic Skylights – Skylights glazed with a plastic lens, most often dome or pyramid shaped. Lenses come in clear, white, or bronze, and are often combined in two layers to make a double dome.
Curb Mounted – Curbs are typically built with 2×4 or 2×6 wood studs secured to the roof deck and made water tight with paper, underlayment, and flashing. The skylight mounts on top of the curb like a lid on a shoebox, secured with screws.
Deck Mounted – Mounted directly to the roof deck. Lower profile than curb mounted, but more difficult and costly to replace.
Diffused Light – Indirect light. Skylights can diffuse light with white acrylic domes, white frosted glass, or light-filtering blinds.
Fixed Skylight – A skylight that is secured down and does not open or vent.
Flashing – A waterproofing system, usually thin sheet metal, that seals the skylight to the roof deck. Header flashing, pan flashing, and step flashing are different types.
Frame – The framing that encases the glass of the skylight, typically aluminum.
Glazing – The glass portion of the skylight. It comes in different thicknesses and specs, including UV-filtering coatings and laminated safety glass.
Joist – The parallel stud beams that support your ceiling.
Laminated Glass – Two panes of heat-treated glass bonded together with a vinyl interlayer that holds the glass together if it breaks. Laminated glass is required on the interior side of all skylights in California.
LoE3 – A metallic coating that improves glass energy efficiency and blocks UV and fading rays. VELUX uses LoE3 on their glass skylights.
Pitch – The angle or slope of a roof.
Rafter – The parallel stud beams that support a sloped roof.
Roof Deck – The supporting structure on top of the roof rafters, typically wood, that your roofing material attaches to.
Roofing Material – The waterproof covering on top of the roof deck. Common types include shingle, shake, composite, tile, and modified bitumen.
Rough Opening – The actual dimensions of the cut opening in the roof deck.
Self-Flashing – A skylight with a built-in metal curb that can be installed directly to the roof deck without building a traditional curb. The tradeoff is that self-flashing units typically require roofing work and resealing when replaced, which drives up the cost.
Shades – Pleated shades, exterior shades, or interior blinds, ranging from light-filtering to room-darkening to full blackout.
Tempered Glass – Glass that has been heat-treated and hardened so that when it breaks, it shatters into small pieces rather than dangerous shards. On a skylight, the tempered layer is the outer pane, facing the weather.
Truss – A rigid framework designed to support the load of a structure.
Underlayment – A waterproofing layer that bonds the skylight to the flashing.
UV Light – Ultraviolet light that can fade and damage the interior of your home over time. Low-E coatings block most UV light.
Venting Skylight – A skylight hinged on one side that opens to let fresh air in, manually operated or solar powered.