TRAPEZOIDAL BRIDGE

The Trapezoidal Bridge is a compact aluminum mounting segment designed for point-based solar panel attachment on trapezoidal sheet metal roofs. Unlike full-length trapezoidal PV profiles that create continuous rail runs across the entire roof width, the Trapezoidal Bridge uses short 300, 330, and 400 mm segments positioned only at each clamp point, bonded directly to the trapezoidal sheet surface using EPDM adhesive tape. This approach creates a non-penetrating mounting solution that preserves the roof’s waterproof membrane completely intact — a critical advantage for buildings where maintaining the roof warranty is a priority. Manufactured from EN AW-6060 T6 aluminum alloy with a 114 mm width matching the full-length trapezoidal profile, these bridge segments are fully compatible with the complete ULAMEX aluminum clamp range. ULAMEX supplies the Trapezoidal Bridge at B2B wholesale conditions from stock in Poland, with European-wide delivery in pallet and full-truck quantities.

Technical Specifications

The Trapezoidal Bridge is extruded from EN AW-6060 T6 (AlMgSi alloy, solution heat-treated and artificially aged), providing a minimum tensile strength of 190 MPa, minimum yield strength of 150 MPa, and minimum elongation of 8%. These mechanical properties ensure that each short bridge segment can reliably transfer the dead load of the solar panel plus dynamic wind and snow loads from the clamp interface through the EPDM bond and into the trapezoidal sheet structure.

At 114 mm width, the Trapezoidal Bridge shares the same bearing dimension as the full-length Trapezoidal PV Profile. This dimensional consistency means that mid-clamps and end-clamps sit in exactly the same geometry regardless of whether they are mounted on a continuous rail or a point bridge — eliminating any compatibility concerns when mixing mounting methods within a single installation or across multiple projects.

The bridge segments are available with integrated EPDM bonding tape on the underside, pre-applied at the factory for consistent adhesive thickness and coverage. The EPDM tape serves three simultaneous functions: it creates a strong adhesive bond between the aluminum bridge and the steel roof sheet, it compensates for minor surface irregularities on the trapezoidal rib, and it provides a permanent moisture seal at the contact interface to prevent trapped condensation from causing corrosion.

Available in heights from 40 to 100 mm, matching the same trapezoidal sheet rib range as the full-length profile. The upper channel accepts M8 sliding inlet nuts with ball retention, square nuts (DIN 557), and hex socket cap screws (DIN 912) for secure clamp attachment.

Channel and Fastening System

The Trapezoidal Bridge operates with a fundamentally different fastening philosophy than screw-through profiles. Roof attachment is achieved via the EPDM adhesive bond between the aluminum bridge underside and the trapezoidal sheet surface. The EPDM tape is a closed-cell elastomer with excellent UV resistance, temperature stability (from −40°C to +80°C), and long-term adhesion to both aluminum and galvanized or coated steel surfaces. This bonded connection is genuinely non-penetrating — no screws pierce the roof sheet, no holes are drilled, and the factory-applied waterproofing membrane remains completely intact.

For installations where additional mechanical security is required — for example, in high wind zones or on buildings with specific structural certification requirements — the bridge segments can be supplementally secured with bi-metal self-drilling screws (6.0×25) and EJ self-drilling screws (5.5×25) from the ULAMEX fastener range. This hybrid approach combines the watertight base seal of the EPDM bond with the shear strength of mechanical fasteners, providing a belt-and-suspenders solution for demanding structural load cases.

Panel attachment uses the upper channel, which accepts M8 sliding inlet nuts, square nuts (DIN 557), and hex socket cap screws (DIN 912). Clamps are positioned and tightened in the same manner as on any ULAMEX PV profile, meaning installation crews use identical tools and procedures regardless of the mounting method.

Installation Applications

The Trapezoidal Bridge addresses specific installation scenarios where full-length continuous rails are either unnecessary, impractical, or undesirable:

• Low-density panel layouts — buildings where only a portion of the roof area is covered with solar panels. Point-based bridge segments are positioned only where clamps are needed, significantly reducing material consumption compared to running full 6.21 m rails across the entire roof width.
• Warranty-sensitive roofs — buildings where the roof manufacturer’s warranty explicitly prohibits or penalizes screw penetration of the trapezoidal sheet. The EPDM-bonded Trapezoidal Bridge provides a genuinely non-penetrating mounting solution that satisfies these warranty conditions. This is particularly relevant for newer buildings with premium metal roof systems.
• Retrofit and mixed-use roofs — existing buildings where the trapezoidal sheet condition varies across the roof area, or where solar panels must be installed around obstructions such as skylights, ventilation units, and roof-mounted equipment. Short bridge segments can be positioned precisely around obstacles without cutting or modifying full-length rails.
• Supplementary mounting points — additional support points added to an existing installation to accommodate new, larger-format solar modules or to address deflection issues identified during post-installation inspection. Individual bridge segments can be bonded to the roof at specific locations without dismantling the existing array.
• Lightweight roof structures — buildings with limited reserve load capacity in the roof purlins or rafters. The point-based approach minimizes the total aluminum weight added to the roof, since material is placed only where structural support is needed rather than continuously across the full span.

For dense panel arrays requiring continuous rail support across the full roof width, the full-length Trapezoidal PV Profile (6.21 m, in the same 40–100 mm height range) is the appropriate choice. For roofs with 25 mm rib heights specifically, see the Trapezoidal PV Profile H25.

Why Choose This Product

The Trapezoidal Bridge occupies a unique position in the ULAMEX PV mounting range: it is the only product that enables fully non-penetrating solar panel mounting on trapezoidal sheet roofs when used exclusively with the EPDM bond. This makes it the default choice for any project where roof penetration is restricted, whether by warranty terms, building regulations, or client preference.

Compared to full-length trapezoidal profiles, the bridge segments offer three distinct advantages: lower material cost per clamp point (you buy only the bridge length you need, not a 6.21 m rail), easier handling (a 300 mm segment weighs a fraction of a 6 m profile and can be positioned by a single installer), and greater layout flexibility (each segment is an independent unit that can be placed at any angle or orientation on the roof sheet).

The trade-off is that bridge segments do not provide continuous rail support between clamp points, so panel deflection between supports is governed by the panel frame stiffness rather than the rail stiffness. For most modern solar modules with robust aluminum frames, this is not a limiting factor in point-based mounting configurations.

Standards and Quality Assurance

The Trapezoidal Bridge is manufactured from EN AW-6060 T6 aluminum per EN 755-2 and EN 573-3. The EPDM bonding tape meets the requirements for closed-cell elastomeric adhesives used in outdoor structural bonding applications, with documented UV resistance, temperature cycling performance (−40°C to +80°C), and adhesion values validated for aluminum-to-galvanized-steel joints. The natural aluminum oxide layer provides corrosion protection in categories C1–C3 per EN ISO 9223. ULAMEX holds EN 1090 certification for structural aluminum components, and all bridge segments are supplied with full material documentation and traceability.

Frequently Asked Questions

Is the EPDM bond strong enough to hold solar panels in high wind?

The EPDM adhesive bond provides reliable adhesion for standard wind load conditions in most European locations. For high wind zones (wind zones 3–4 per EN 1991-1-4) or exposed building positions, we recommend the hybrid approach: EPDM bonding combined with supplementary bi-metal self-drilling screws from our fastener range. This provides both the waterproof seal of the EPDM and the mechanical shear resistance of the screws.

Which segment length should I choose: 300, 330, or 400 mm?

The 300 mm segment is the standard choice for most installations, providing adequate bonding area and clamp support for residential and light commercial applications. The 330 mm segment offers a slightly larger bonding surface for moderate wind zones. The 400 mm segment provides the maximum bonding area and is recommended for high wind zones, heavy-format modules (400W+), or projects requiring the highest mechanical safety margin.

Can I combine bridge segments with full-length trapezoidal profiles on the same roof?

Yes. Both the Trapezoidal Bridge segments and the full-length Trapezoidal PV Profile share the same 114 mm width and upper channel geometry. The same clamps and fasteners work on both. A common approach is to use full-length profiles for the densely-paneled main roof area and bridge segments for isolated panels near roof edges, skylights, or ventilation equipment.

How many bridge segments do I need per solar panel?

A standard solar module requires a minimum of four clamp points — two mid-clamps on the long edges. Each clamp point requires one bridge segment, so a minimum of four segments per module in a point-based layout. In continuous row configurations where adjacent modules share mid-clamp positions, the per-module requirement decreases. Consult the module manufacturer’s installation manual for the exact number and position of required clamp points based on your specific module dimensions and load case.