Autarco Matrix mounting for flat roof installations is designed to be a non-penetrating mounting system. Ballast is used to make sure it stays in place on the roof and will not be affected by wind. Based on your layout and set parameters, Helios will calculate the amount of ballast needed per module position. To do so, all modules within an installation area are broken down to arrays, for which ballast is calculated individually.

In order to get the best results from the ballast calculation, it is advised to make your installation area closely match the shape of the entire roof you’re working on. This way, wind pressure and edge zones will be calculated correctly.

When designing on a flat roof, the ballast tab will appear in the side menu after placing modules. You can set the following parameters:

• Edge zone – defined by building dimensions, modules within a certain distance of the roof need extra ballast to account for larger wind pressures. You will see the edge zone displayed on your layout when the ballast tab is selected.
• Basic wind speed – this is the basis for all ballast calculations. In the Netherlands and Belgium, wind speeds are automatically set based on your system’s location.
• Surroundings – these need to be adjusted depending on the system’s location, and will define the terrain category used in the calculations.
• Roofing type – select the roofing material. This will influence the required amount of ballast, since different materials have different friction coefficients.
• Tile – select the ballast tile you will be using.

The ballast plan is created on these values and adjusted real time on your layout.

When wind pressure on your installation is high, a ballast plan may come out quite heavy or even not be possible at all. There are some ways to try to get to a better solution:

• Adjust the tile weight: there are limits to the total weight and the number of tiles that can be placed on a single ballast plate. For example, if you need 55 kg of ballast for a given position, and there is only room for 5 tiles, 10 kg tiles won’t lead to a feasible ballast plan. But change the tile weight to 11 kg and it will work just fine. This works the other way around as well, lowering the tile weight might lead to a lighter ballast plan overall.
• Move your modules outside the edge zone: modules in the edge zone of a building require more ballast, since wind pressure is higher at these locations. If your ballast plan is too heavy or not feasible, try to move your modules away from the edge zone.
• Simplify your layout: the connection between modules create strength within the mounting system, resulting in lower ballast needs. Fragmented layouts with single rows or columns, small arrays and gaps will require more ballast than a simple and large rectangular shape.

When working on the ballast plan, you’ll immediately see the plan displayed on your layout. In the ballast tab in the menu, you will get the following results:

• Number of tiles – the total number of tiles you need for this installation area.
• Number of racks – the total number of ballast racks within this installation area.
• Total weight – combined weight of the modules, mounting system and ballast.
• Average weight – weight in kg/m², for the area occupied by the installation.
• Max pressure – the maximum pressure under the feet of the mounting system.

After saving the layout, you can navigate to the ballast plan page. Here you’ll find three tables holding all relevant information:

• Ballast plan overview – information of weight and tiles per area.
• Installation area details – the settings you choose for each area, like height, roofing type and wind conditions.
• Ballast plan per array – a more detailed version of the first table, where the information is broken down to the different arrays within an area.

These tables can be included in the system report, together with a screenshot to indicate where the arrays are situated.

The ballast plan generated by Helios is only applicable when the roof pitch is 2 degrees or less.

Between 2 and 5 degrees a special ballast plan is required or the mounting system should use penetrating roof anchors. Please contact the sales team for advice.

The Matrix Mounting system is not suitable for applications with a pitch greater than 5 degress.

Calculations are based on Eurocode EN-1991 1-4, NEN7250 and wind tunnel tests of our mounting systems.