The ULAMEX mounting plate is a stainless steel adapter component that bridges the connection between roof hooks and PV mounting profiles. Its elongated 11 mm slot accepts the threaded shank of a double-threaded screw (Stockschraube / hanger bolt) protruding from the roof hook, while the plate itself is bolted to the PV profile using M8 or M10 fasteners through standard T-slot connections. This two-stage connection — hook to plate, plate to profile — provides critical lateral adjustment capability that compensates for the inevitable misalignment between roof rafter positions and the ideal rail spacing dictated by module dimensions.
Technical Specifications
| Property | Value |
|---|---|
| Material | H17 stainless steel (1.4016 / AISI 430 — ferritic) |
| Size — Variant A | 80 x 30 x 5 mm |
| Size — Variant B | 80 x 25 x 4 mm |
| Slot Width | 11 mm (both variants) |
| Slot Orientation | Longitudinal — allows lateral adjustment along the plate length |
| Compatible Profiles | PV Profile 40×40 mm, PV Profile 80×40 mm |
| Compatible Fasteners | Double-threaded screws (M10 wood / M8 metric), DIN 912 bolts |
| Plate Thickness | 5 mm (Variant A) / 4 mm (Variant B) |
| Surface Treatment | None required — inherent stainless steel corrosion resistance |
Installation Guidelines
The mounting plate is installed as the intermediate layer in a three-component stack: roof hook (bottom) — mounting plate (middle) — PV profile (top). The installation sequence follows these steps:
- Mount the roof hook to the rafter using the appropriate lag screw or coach bolt. The double-threaded screw should protrude vertically from the hook’s top flange with enough thread length to accept the mounting plate and a securing nut above it.
- Slide the mounting plate over the protruding double-threaded screw shank, passing the screw through the 11 mm slot. The slot allows lateral adjustment of approximately +/-30 mm relative to the hook position — use this range to align the plate with the desired profile position.
- Secure the plate to the double-threaded screw with a hex nut and EPDM washer above. Tighten to 20–25 Nm for M10 connections.
- Place the PV profile on top of the mounting plates. Bolt the profile to each plate using M8 bolts with threaded plates inside the profile channel. Tighten to 12–14 Nm.
Variant selection: The 80x30x5 mm variant (thicker, wider) is recommended for standard installations and higher wind-load zones, where the additional plate width provides a larger bearing surface and higher bending resistance. The 80x25x4 mm variant (thinner, narrower) is suitable for lighter-duty residential installations and where space constraints between parallel hooks are tight.
Applications in Photovoltaic Mounting
- Pitched roof installations — the primary application; mounting plates bridge the roof hook to the PV rail on tile, slate, and corrugated roofs, compensating for rafter spacing irregularities
- Height compensation — by using different washer/spacer stacks above and below the mounting plate, installers can level the profile plane across an uneven roof surface
- Lateral alignment — the 11 mm slot provides +/-30 mm adjustment perpendicular to the profile run, critical when rafter centres do not align precisely with the required hook spacing
- Retrofit installations — when adding a second row of modules to an existing roof, mounting plates allow fine-tuning the new rail position relative to the existing hooks without re-mounting the substructure
- Snow guard integration — in alpine and Nordic regions, mounting plates can serve as attachment points for snow guard rails that protect the lower edge of the array from sliding snow loads
Material Properties
The mounting plate is manufactured from H17 stainless steel (1.4016 / AISI 430), a ferritic chromium stainless steel containing 16–18% chromium. This grade was selected for mounting plates because of its combination of structural strength and corrosion resistance at an economical price point.
The 5 mm thickness of variant A provides a section modulus sufficient to resist bending moments from wind uplift forces transmitted through the profile-to-plate connection. Under Eurocode EN 1991-1-4 wind loading for Central European installations (wind zone 2–3), the plate maintains a safety factor above 2.0 at the design load case. The 4 mm variant B is dimensioned for lower wind-load categories and residential-scale installations.
The ferritic stainless steel structure provides higher yield strength than austenitic A2 grade in equivalent thicknesses, which is advantageous for plates subjected to bending loads. The material is magnetic, resistant to stress corrosion cracking (a known failure mode of austenitic stainless in certain environments), and has a lower coefficient of thermal expansion than A2 — reducing thermal cycling stress at bolt connections.
For installations in coastal, marine, or chemically aggressive environments, contact our sales team regarding availability of mounting plates in A4 stainless steel (1.4401) for enhanced corrosion protection.
Compatibility
ULAMEX mounting plates are designed as the universal adapter between the roof substructure and the PV rail system:
- Below the plate (substructure side): Compatible with all ULAMEX roof hooks that use M10 double-threaded screws — including tile hooks, slate hooks, corrugated sheet hooks, and trapezoidal sheet hooks
- Above the plate (profile side): Compatible with all PV mounting profiles in 40×40 mm and 80×40 mm cross-sections
- Fasteners: Use with M10 hex nuts and EPDM washers on the substructure side; M8 DIN 912 bolts with threaded plates on the profile side
Why ULAMEX
ULAMEX is a B2B wholesale specialist for photovoltaic mounting systems, supplying professional installers and distributors across Europe. Our mounting plates are manufactured from verified 1.4016 stainless steel with precision-cut slots and clean edges — no deburring required on site. We stock both variants for immediate dispatch and offer attractive volume pricing that scales with your project size. As a single-source supplier of the complete PV mounting bill of materials — profiles, clamps, roof hooks, fasteners, and all accessories — ULAMEX simplifies your procurement and consolidates your deliveries.
Frequently Asked Questions
- Why do I need a mounting plate between the roof hook and the PV profile?
- The mounting plate provides lateral adjustment that compensates for the mismatch between roof rafter positions (which determine hook placement) and the ideal rail spacing (which is determined by module dimensions). Without the plate, the hook position would need to exactly match the profile attachment point — which is rarely possible in practice.
- What is the difference between variant A (80x30x5 mm) and variant B (80x25x4 mm)?
- Variant A is thicker and wider, providing higher bending resistance and a larger bearing surface. It is recommended for standard and high-wind installations. Variant B is thinner and narrower, suitable for light-duty residential installations and tight-clearance situations.
- Can I use the mounting plate without a roof hook?
- The mounting plate is designed as an adapter for roof-hook-to-profile connections. For direct-to-structure mounting (e.g., on steel purlins or concrete decks), different mounting solutions — such as direct-bolt clamps or rail feet — are typically more appropriate. Contact our team for advice on your specific application.
- How many mounting plates do I need per module?
- The number depends on the number of roof hooks under each rail. Typically, one mounting plate per roof hook. For a standard residential installation, plan 2–3 hooks per rail per module length, which translates to 4–6 mounting plates per module (2–3 on each of the two parallel rails).
Need mounting plates for your PV installation project? Request a quote — ULAMEX supplies wholesale quantities at B2B conditions with fast European delivery. Browse our complete photovoltaic mounting range for single-source procurement.