INTERFACES

Typical Connection Details

The clamping line is where an ETFE roof is won or lost. It holds the foil, transfers its tension into the structure, forms the weather seal and — on cushion systems — carries the air supply. The details below are indicative arrangements; every project is issued with its own fully dimensioned shop drawing package.

Dimensioned detail of the perimeter keder seam — a 55 mm keder bag with a 7 mm EPDM keder, and the seam width between welded strips

Section drawing of a cushion edge clamp: upper and lower ETFE foils meeting at a clamping plate on an extrusion carried by a steel support, with the air inlet marked — **A · Cushion edge clamp** Upper and lower foils welded to a keder edge, clamped between the base extrusion and a bolted plate, air inlet through the extrusion.

Section drawing of a single-layer edge: one ETFE membrane clamped at both sides with a restraint cable beneath, supported on columns off the structural line — **B · Single layer edge** Single welded skin clamped into the perimeter extrusion, with stainless steel restraint cables controlling deflection under uplift.

Section drawing of a perimeter condition: ETFE panel and extrusion on a steel support beside a fabricated gutter with its outlet — **C · Perimeter & gutter** Extrusion supported off the primary steel, discharging into a fabricated gutter with brackets and outlet.

Maintenance, Repair & Warranty

What happens after handover: how the surface stays clean, how damage is repaired, how the inflation plant is serviced and what is warranted.

CLEANING

ETFE is extruded, not woven or coated, so its surface is exceptionally smooth and non-adhesive. Very little dirt is retained and rain removes most soiling — including bird droppings — on its own. As a guideline, cleaning every 2 to 3 years is sufficient. Only light pH-neutral detergents are used.

REPAIR & REPLACEMENT

ETFE has exceptional tear resistance and no notch weakness. Minor damage such as a puncture is patched in situ within a short timescale. Where a cushion is significantly damaged, that single cushion is removed and replaced with minimal disruption to the rest of the roof — worked under IRATA / BS 7985 rope access procedures.

SERVICING & RESPONSE

Cushion roofs depend on their inflation plant, so we recommend servicing the air handling units twice a year. TMSI operates a dedicated maintenance department handling both planned and emergency works, with 24-hour technical support. Where remote monitoring is installed, faults are diagnosed remotely first.

WARRANTY

ETFE foil systems are supplied with a standard 5 year warranty. An extended 10 year warranty is available at additional cost on request. Warranty terms are confirmed against the final specification at contract stage.

Visual inspection of the cushions and foil surfaces
Fixity of cappings, clamps, brackets and connections
Air delivery pipework and joint integrity
Air handling unit testing and filter replacement
Fine tuning of pressure and fan operation
Repair of any minor holes or tears found

Design Notes

The extrusion line is surveyed in position before any panel is opened — fabricated foil cannot be adjusted on site
Clamping bolts are torqued in a defined sequence to distribute the load evenly along the keder
Thermal movement of the aluminium and the supporting steel is accommodated in the fixing arrangement

All clamping and support components are clear anodised aluminium as standard, or coated to the architect’s specification
Bird deterrent wire is provided over the extrusion and steelwork to prevent perching and the damage that follows
Air inlet positions are coordinated with the pipework route at detail design stage