ULAMEX PV Installation Tapes are a range of specialist adhesive and gasket tapes selected for the critical interface zones in photovoltaic mounting systems — where dissimilar metals meet, where roof surfaces are penetrated, and where vibration transfer must be controlled. Available in three types — EPDM rubber tape, Butyl sealing tape, and PES (polyester) tape — each addresses a specific installation requirement that protects the long-term integrity of the PV system and the building envelope beneath it.
Technical Specifications
| Tape Type | Material | Width | Thickness | Length / Roll | Primary Function |
|---|---|---|---|---|---|
| EPDM tape | EPDM rubber (ethylene propylene diene monomer) | 20 mm | 2 mm | ~10 m | Galvanic isolation, vibration damping |
| Butyl tape | Butyl rubber (self-adhesive) | 20 mm | varies | per roll | Waterproof sealing of roof penetrations |
| PES tape | Polyester (woven PES fabric) | 20 mm | varies | per roll | Surface protection, anti-scratch separation |
Installation Guidelines
EPDM Tape — Galvanic Isolation: Apply EPDM tape to the contact surface between dissimilar metals before assembly — for example, between a stainless steel roof hook base plate and the aluminium mounting rail, or between a galvanised steel mounting plate and an aluminium profile. Cut a strip to length, peel the release liner (if present), and press the tape onto the lower component surface. Position the upper component on top and tighten the fasteners through both layers. The 2 mm EPDM layer electrically isolates the two metals and prevents galvanic corrosion cell formation while still transferring compressive loads through the joint.
Butyl Tape — Roof Penetration Sealing: Apply butyl tape around the base of roof hooks, mounting brackets, or any component that penetrates or bears directly on the roof covering. Butyl tape is self-adhesive and permanently tacky — it conforms to irregular surfaces (roof tiles, corrugated sheet) and creates a watertight seal without curing or hardening. Press firmly to ensure full contact with both the component base and the roof surface. Butyl sealing is especially critical at tile-replacement hook positions where the original weatherproofing is compromised.
PES Tape — Surface Protection: Apply PES tape between metal components and sensitive surfaces to prevent scratching, marking, or abrasion during installation and in service. PES tape is commonly used between PV profiles and coated roof tiles to protect the tile glaze, or between clamp assemblies and the module frame to prevent anodising damage. The woven polyester structure provides a durable anti-scratch barrier that does not degrade under UV exposure or thermal cycling.
Applications
- Galvanic corrosion prevention — EPDM tape between stainless steel and aluminium, galvanised steel and aluminium, or copper and aluminium contact points in PV mounting systems
- Roof penetration waterproofing — Butyl tape sealing around roof hooks, hanger bolts, and mounting bracket base plates on tile and sheet roofs
- Vibration damping — EPDM tape between rail and roof hook to absorb wind-induced vibrations and reduce acoustic transmission to the building interior
- Tile and panel surface protection — PES tape preventing contact damage to coated roof tiles, standing-seam panels, and module frames
- Thermal break — EPDM tape reducing direct heat conduction between sun-heated aluminium rails and the roof structure
- Cable route protection — PES tape wrapping cable runs at metal edge crossings to prevent insulation chafing
Material Properties
EPDM (Ethylene Propylene Diene Monomer): A synthetic rubber with outstanding UV resistance, ozone resistance, and thermal stability (-40 to +130 °C). EPDM does not harden, crack, or lose elasticity over the 25+ year service life of a PV installation. Its electrical resistivity (>10¹³ Ω·cm) provides effective galvanic isolation even at the thin 2 mm tape thickness. The closed-cell structure prevents moisture absorption, ensuring consistent isolation performance in wet conditions.
Butyl Rubber: A permanently tacky, non-curing sealant that maintains adhesion and flexibility from -30 to +80 °C. Unlike silicone or polyurethane sealants that cure to a solid, butyl remains plastic and self-healing — if a roof hook shifts slightly during thermal cycling, the butyl tape reseals the contact area. This makes butyl the preferred roofing sealant for dynamic joints.
PES (Polyester): Woven polyester fabric with high tensile strength and abrasion resistance. UV-stable, chemically inert, and non-conductive. The woven structure provides cushioning without compression set, maintaining the separation layer thickness over the installation lifetime.
Compatibility
ULAMEX PV tapes are used with all mounting system components:
- ULAMEX roof hooks — EPDM isolation between hook and rail; Butyl sealing at tile penetration
- PV mounting rails 40×40 and 80×40 — EPDM between rail and dissimilar-metal mounting points
- Module clamps — PES between clamp and module frame for anodising protection
- PV triangles — EPDM isolation at steel-to-aluminium interfaces on flat-roof systems
- Ballast systems — EPDM between ballast tray feet and roof membrane for waterproofing protection
Why ULAMEX
ULAMEX is an EN 1090 certified B2B wholesaler supplying the complete PV mounting system — including the accessory tapes that professional installers need for a durable, code-compliant installation. All three tape types are stocked for immediate dispatch alongside profiles, roof hooks, clamps, and fasteners. One supplier, one delivery, one invoice.
Frequently Asked Questions
Q: When is EPDM tape required between metals?
EPDM isolation tape is required whenever two different metals are in direct contact in an outdoor environment — the combination of moisture and dissimilar metal contact creates a galvanic cell that accelerates corrosion. Common PV examples: stainless steel roof hook on aluminium rail, galvanised steel bracket on aluminium profile, copper earthing conductor on aluminium rail. Use EPDM tape at every such interface.
Q: Can butyl tape replace silicone sealant for roof sealing?
For PV roof hook installations, butyl tape is preferred over silicone. Butyl remains permanently flexible and self-healing — it accommodates the slight movements caused by thermal expansion. Silicone can debond from smooth metal surfaces over time and cannot reseal after displacement. Butyl also requires no curing time, allowing immediate installation continuation.
Q: Does EPDM tape reduce the clamping force of bolted joints?
The 2 mm EPDM tape compresses under bolt tension but does not significantly reduce clamping force. However, re-torque after 24 hours is recommended for joints with EPDM isolation, as the rubber undergoes a small initial compression set. The re-torque restores the target clamping force and ensures long-term joint stability.
Q: Which tape do I need if I am only ordering one type?
EPDM tape is the most versatile — it handles galvanic isolation, vibration damping, and basic surface protection. If you only stock one tape type, EPDM 20×2 mm covers the widest range of PV installation requirements.
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