Rooflight advice

Stratus Flat Skylights: Understanding Span and Slope

The Stratus flat skylight designer uses internal kerb dimensions labelled span and slope. Keep those labels on the survey and order drawing so that the unit’s orientation remains clear throughout the build.

Use the product’s own measurement language

Measure from the reference faces shown in the current Stratus drawing. Mark span, slope and the direction of fall on the plan. Do not swap the numbers because one side looks like the length of a rectangle; the product’s labels define how the dimensions must be interpreted.

Read the configuration matrix

Check the complete size combination offered by the designer and the current technical guide. Published maximum dimensions are not permission to combine any two values. If your intended size is outside the available combinations, contact us before changing either the opening or the order dimensions.

Coordinate the kerb before construction

Share the Stratus technical and installation documents with the builder and roofer before the upstand is finished. Ask them to confirm the internal dimensions, support, fall and waterproofing junction for the selected unit. A section drawing helps coordinate insulation, membrane and internal lining.