#RAFTERPURLIN SPACING SLANTED METAL ROOF WINDOWS#

See the discussion on moisture protection in Glazing that applies here as well. The leakage and condensation must be collected and drained to the exterior with a continuous drainage system consisting of interconnected condensate gutters and sill flashing.

#RAFTERPURLIN SPACING SLANTED METAL ROOF WINDOWS#

Similar to windows and curtain walls, skylights are subject to wintertime condensation when the surface temperature of the interior glass surfaces falls below the dew point for the interior conditions. Even for new, well-sealed skylight assemblies, some leakage beyond the exterior glazing is inevitable. Moisture Protection (Water Penetration, Condensation Resistance)įunctionally, skylights are roofs and are therefore exposed to a larger volume of rainwater and are much more susceptible to water leakage than vertical fenestration systems. The thermal performance of a skylight is largely a function of the thermal performance of the glazing see the discussion in Glazing on thermal performance. This aspect of the design is discussed in the Building Envelope Design Guide page Atria Systems.

Skylights experience significant summertime solar heat gain and wintertime heat loss that must be calculated and accounted for in mechanical design. Fundamentals (Functions) Thermal Performance (Conduction, Solar Radiation, Thermal Break, Comfort) Unit Failure Avoidance and Fracture and Glazing Retention (below) for typical configuration and design advice), but also proprietary translucent products, such as fiberglass sheets or fiberglass sandwich panels (not addressed in this page). Infill panels: Generally glass (see Designing for Finish Durability- I.G. The pressure bars are frequently covered by rafter caps to conceal the fastener heads and shield them from rainwater. Supporting members: Rafters spanning from sill to ridge, cross bars between the rafters, and pressure bars that that clamp the edges of the glass to the rafters. The following covers brief descriptions of typical skylight components: These unit skylights are not specifically addressed in this page. In the construction industry, the term 'skylight' is often applied to relatively small shop-fabricated unit-skylights, frequently with plastic glazing. This page uses the term 'skylight' to describe field-assembled systems of sloped glazing. units made by glazing fabricators, but they share common design elements required to make them perform. Skylights are engineered systems that are assembled from standard or custom extrusions provided by skylight manufacturers, and i.g.

single slope, ridge, pyramid, barrel vault). Most contemporary skylights now consist of insulating glazing captured in aluminum frames that in many configuration (e.g. Early skylight systems consisted of plate glass (later wire glass) in metal frames and frequently incorporated both an exterior skylight and a decorative interior 'diffuser' or 'laylight'. Skylights have been used for over a century to provide interior daylighting.

Rafterpurlin spacing slanted metal roof