Preface

Prefa brand solar brackets and mounting technology

Today, over 720 employees work at the family-owned company , with production facilities in Marktl, St. Pölten, and Wasungen, Germany. In addition to roofs and facades, their product range includes roof drainage, flood protection, and solar systems.

We are interested in the part that sits between the roof and the module: brackets, rails, clamps, and connectors. Because a metal roof is constructed differently than a tile roof, Prefa uses its own components here instead of standard products. Suitable systems from other manufacturers for tile, trapezoidal, and flat roofs can be found in the substructure section.

The manufacturer's in-roof products are not part of our product range. PREFALZ solar roof panels and solar modules replace the roof covering itself; they are installed by a roofing contractor, not through mail order. We supply the mounting hardware, not the complete roof.

Photovoltaics without roof penetration on the Prefa roof

Why use a brand-specific bracket at all? An aluminum roof relies on its closed surface. As soon as a standard roof hook is inserted through the metal, an opening is created precisely where the material provides its protective function. In all likelihood, this voids the manufacturer's warranty on the roof, i.e., on the most expensive part of the entire structure.

Prefa's PREVARIO solar mounting system solves this problem differently. The brackets grip the existing standing seam or panel structure instead of penetrating it ; rails and module clamps then rest on top. This leaves the roof's function and lifespan unaffected, which is a crucial factor for a roof with decades of remaining service life.

If the roof is older, it's worth checking the condition of the seams beforehand. Deformed or repeatedly reworked areas won't hold a clamp as well, and this can only be corrected with considerable effort on the finished roof.

This logic doesn't apply to tiles or trapezoidal metal roofing; conventional roof hooks are used there. We carry corresponding systems from K2 Systems . The Prefa PV mounting system remains a special case for metal roofs, not a universal product.

Safely dissipating snow load and wind suction in the Alpine region

At an altitude of 900 meters, more than a ton of snow can quickly accumulate on a single row of modules in February. This load is transferred via the brackets and rails into the roof structure. It is only distributed evenly if the bracket spacing is appropriate for the load.

The amount of snow load required depends on the location. While around 1 kN/m² is often used in lowland areas, mountainous regions experience significantly higher loads. Therefore, a system that holds up in Vienna is far from being adequately secured in the Zillertal valley. The required spacing of the Prefa brackets is ultimately determined by the structural analysis.

Dimensioning is based on ÖNORM EN 1991-1-3 for snow loads and ÖNORM EN 1991-1-4 for wind loads. Wind suction is significantly stronger at the edges and corners of the roof than across the surface , which is why the supports are placed closer together in these areas. Using spacing based on the center of the roof will underestimate the exact point where the system is likely to lift off.

A Prefa PV substructure is therefore never calculated as a flat rate, but rather based on location, roof pitch, and module area. The figures for this are provided by the structural analysis, not the data sheet.

Prefa solar brackets for standing seam roofs in detail

The type of roofing material determines which bracket is suitable. A Prefa solar bracket for standing seam roofs clamps onto the standing seam, while flat roof panels require a system-specific bracket that engages with the panel structure. The following overview categorizes the common cases:

The first two lines explain why a Prefa solar panel bracket cannot be replaced with a universal part: Both principles require the exact geometry of this roof covering. Pre-assembled packages for common roofs are available in the mounting kit.

Then there's the question of orientation. The fold determines the direction, the rails run perpendicular to it. With a vertical fold, this results in horizontal rows of rails, which determines the rail length, the number of rails, and ultimately the material cost of the system.

Professional assessment of the roof condition before purchase

Four pieces of information are sufficient for us to provide reliable advice: roofing type, roof construction year, module dimensions, and roof pitch. The type of Prefa roofing you have is usually noted in the roofer's handover report. This information will then determine how many brackets are needed per module row.

If you would like to purchase Prefa solar brackets, you can currently do so by contacting us via phone, WhatsApp, or chat. We can procure items not listed, including the type name, quantity, price, and delivery date, in advance.

We calculate project quantities separately for plumbing and electrical contractors. Goods are shipped from our warehouse in the Zillertal valley to Austria and Germany on short notice; larger deliveries are scheduled to coincide with the construction site date.

If you're unsure whether your roof can even support a rooftop solar system, please tell us openly. Sometimes the honest answer is that a structural engineer or a trusted roofer should inspect the roof first. A bracket that isn't compatible with the roofing material won't be improved by a quick delivery.