Treat the ridge as a complete junction
The visible ridge flashing is only the outer skin. Inner flashing, core continuity, shaped fillers, sealant lines and fasteners must work together against wind-driven rain, air leakage and thermal discontinuity. Match the exact panel model, core, thickness, slope, ridge purlins and project loads to the manufacturer's detail; a fixing pitch or filler arrangement from another system is not a universal rule.
Verify geometry and surfaces
Check both slopes, the straightness of the ridge and panel end gaps before closing the joint. Correct purlin level or panel damage instead of hiding it with sealant. Remove swarf and dirt, repair permitted coating damage and apply tapes only to clean, dry surfaces using the manufacturer's approved cold-cutting and preparation methods.
Install concealed components in sequence
Kingspan guidance places the internal ridge flashing before panels are lifted and calls for sealant at flashing overlaps, followed by sealing tape at the required edges. Keep laps facing the intended drainage path, avoid stretched or wrinkled tape and maintain continuous sealant beads at the positions shown in the system drawing.
Fill the gap for the actual core
Ruukki describes polyurethane foam and shaped polyethylene seals for specified foam-core ridge details, with mineral wool plus foam in some thicker-panel arrangements. Mineral-wool-core panels require a different mineral-wool and butyl-based detail. Do not substitute an unverified filler or assume fire performance; follow the approved system and project specification.
Fit profile fillers accurately
Use fillers shaped for the exact outer rib profile, with no reversed, crushed or open sections. Join strips without gaps while preserving any designed drainage or ventilation opening. Roof ventilation is a separate engineered function and must not be improvised by leaving the ridge seal incomplete.
Fasten the outer ridge without stress
Place the outer flashing evenly over both slopes after concealed seals are inspected. Use the specified coated fasteners and sealing washers in the approved panel zone. Do not drive screws at an angle or crush washers and sheets. Flashing width, gauge and fixing spacing must come from the selected system and wind design.
Inspect laps and intersections
Check longitudinal laps, end closures and intersections with parapets, rooflights or level changes separately. Sealant must remain continuous, cut edges protected as specified and water paths free of pockets or reverse laps. Account for incompatible-metal contact rather than relying on a final bead of sealant.
Recheck after the first severe weather
Inspect straightness, washers, filler ends and excess sealant, then remove all metal debris. After the first heavy rain and wind, examine the internal ridge for water, air leakage or condensation. Diagnose the lap, filler, seal and fastener path together instead of masking the symptom with random exterior mastic.