Roof trusses are increasingly being designed with a view to future photovoltaic installations. For many investors PV panels have become a standard feature of the modern home. However, such an installation generates additional load that the roof structure must safely support over many years of use. That is why it is so important to take photovoltaics into account right from the design stage of the building and the entire roof.
PV panels and roof structure – how much does a photovoltaic system weigh?
Roof trusses must take into account the additional load generated by the photovoltaic system. Many investors focus mainly on the panels’ power output and installation costs, and pay far less attention to their weight. A standard photovoltaic panel usually weighs between 20 and 30 kilograms. Added to this are the mounting structure, cabling and fixing components.
In practice A complete photovoltaic system can generate a load of around a dozen or so kilograms per square metre of roof surface. For a well-designed structure, this is not a problem. Problems arise when the roof has not been designed to withstand additional loads or was constructed without sufficient load-bearing capacity.
A new house versus an existing building – the differences matter
The most convenient scenario is when an investor plans to install a photovoltaic system before construction begins. The structural engineer can then immediately take the additional loads into account and select the appropriate specifications for the entire roof – trusses taking PV into account They will initially be oversized, but will ultimately meet the requirements of the photovoltaic system. This approach avoids the need for subsequent modifications, structural reinforcement or restrictions on panel placement.
The situation is different in older buildings. In an existing house, you must first check the condition of the structure and its actual load-bearing capacity. This applies particularly to older roofs built using traditional methods. Not every structure was designed to withstand additional loads. Therefore, before installing the system, it is worth assessing not only the roof covering but also the entire load-bearing structure of the roof.
How do trusses cope with a solar panel installation?
Modern roof trusses work very well with PV systems. However, the way they are designed and the quality of the entire structure are of great importance. At Wascovilla, we use technology MiTek, which allows the structural parameters to be calculated with great precision even before production begins. The design takes into account, amongst other things:
- type of roofing,
- snow and wind zone,
- planned live loads,
- additional components installed on the roof surface.
As a result the load on the trusses from the solar panels can be anticipated as early as the design stage. This is a much safer solution than reinforcing the finished structure at a later stage.
The technology of prefabricated trusses also ensures a high degree of consistency in construction. Each component is manufactured in accordance with the technical documentation and precise structural calculations. This is particularly important for modern roofs with large spans and extensive roof surfaces.
It’s worth preparing the roof design in advance
More and more investors are viewing solar panels as a natural feature of a modern home. In practice, this means it is worth considering them as early as the roof design stage, even if the installation itself will take place later.
Well prepared design of trusses for a photovoltaic system enables:
- safely carry additional loads,
- avoid costly structural alterations,
- it is better to plan the layout of the panels,
- maintain the overall appearance of the roof,
- to improve the safety of long-term operation.
In the case of modern prefabricated and energy-efficient homes, this approach is now becoming the norm.
Photovoltaic systems and roof trusses should be designed to work together from the outset
A well-designed roof is not just about the building’s appearance, but above all about the safety and durability of the entire structure. If you are building a house and plan to install rooftop solar panels on a truss roof, ... it is worth taking this into account as early as the house design or roof construction stage.
At Wascovilla, we design and manufacture modern roof structures designed to meet the practical demands of modern construction. Thanks to MiTek technology, we can precisely tailor the truss specifications to the anticipated load and the future PV installation.
Contact us and find out how we can design a roof structure tailored to your project.
