Sundries: sealants, closures, rivets and tapes

Why sundries matter

Sundries are the small consumable items supplied with a steel building to make the envelope weathertight and finish the details: foam closures, mastic tapes, sealants, blind rivets, flashing tapes, touch-up paint and the like. They are a tiny fraction of the building's cost, but most envelope complaints – leaks at laps, dust or birds entering at the eave, rust stains, rattling trims – trace back to a missing or wrong sundry item. A complete PEB kit therefore lists sundries by type and quantity on the bill of materials, matched to the specific sheeting profiles and coatings, and ships a small spare allowance for site losses. Structural and cladding fasteners are covered separately in structural bolts and cladding fasteners.

Foam closures

Profiled sheeting leaves open voids at the eave, ridge, base of walls, above block walls and at canopy junctions. Foam closures – strips of closed-cell polyethylene (or EPDM for higher temperatures) cut to the exact rib shape of the sheet – fill these voids and keep out wind-driven rain, dust, insects, birds and rodents. Inside closures sit between the sheet and the supporting member; outside closures sit between the sheet and the trim. Key selection points:

• The closure must match the specific profile – a closure for a different rib spacing leaves gaps.
• Closed-cell, UV-stabilised material that does not absorb water; open-cell foam holds moisture against the steel.
• Self-adhesive or mastic-bedded closures at the high end of standing seam roofs; vented closures where roof-space ventilation is required.
• Fire-rated closures (mineral wool or intumescent) where the wall or roof forms part of a fire-rated assembly.

Mastics, sealants and tapes

Sealants work only on clean, dry, oil-free surfaces and within their movement capability, which is classified in ASTM C920, EN 15651 or ISO 11600. Sealant is a back-up to correct lapping, not a substitute: water must always be shed by laps facing downslope, as explained in trims and flashings.

Blind rivets, touch-up and other items

• Blind (pop) rivets – typically 4.0–4.8 mm aluminium or stainless steel, used to stitch trim laps, gutter joints and flashings where a self-drilling screw would be unsightly or could not grip. Aluminium rivets suit aluminium-zinc coated sheet; stainless rivets suit stainless trims; avoid copper or steel-mandrel rivets that can leave rust or galvanic stains.
• Touch-up paint – matched to the sheeting colour and the frame primer, used for minor handling damage only. Large damaged areas should be replaced, not painted.
• Stitching screws and lap screws – short self-drilling screws for side laps of sheeting.
• Insulation tapes – foil or vapour-retarder tapes to seal joints in facing films, essential for condensation control.

Compatibility is the hidden risk: copper, lead, green timber, wet concrete and acid-cure sealants all damage zinc and aluminium-zinc coatings. Check every sundry against the sheeting manufacturer's compatibility guidance.

Supply and site practice at World Steel

World Steel lists sundries per elevation and per sheeting profile on its erection drawings and packing lists, sources sealants and fasteners from established manufacturers such as Sika, SFS and EJOT where specified, and packs them in sealed, labelled cartons with the cladding so that nothing is lost in transit. Sundries are part of the accessories and cladding packages and are checked in final inspection before export.