A Cathedral Ceiling is when the pitch of the roof is exposed to the room below. The finishing (drywall, or tongue & groove wood) is attached to the underside of the roof rafters, following the pitch of the ceiling. The space in between the rafters is usually insulated to conserve energy consumption. Another finishing style for a Cathedral Ceiling is when rafters are exposed. A Cathedral Ceiling is not to be confused with a Vaulted Ceiling, which is typically an arch shape.
A skylight installed in a cathedral ceiling usually has s shallow lightwell, determined by the thickness of the roof rafters. Typically the lightwell is splayed at the top and bottom and perpendicular on the sides. The splayed lightwell maximizes the distribution of light and creates a beautiful architectural feature. Multiple skylights can be installed in a row, producing a dramatic visual effect that allows in a significant amount of light, perfect for a kitchen or sunroom.