Many families and self-built homeowners want to install rooftop solar power, but they are always concerned about one core issue: Will rooftop solar PV damage my house? Will it leak, collapse the roof, or pose safety hazards?

As a mainstream installation scenario for distributed solar PV, rooftop solar PV, as long as it is designed correctly, constructed according to standards, and undergoes compliant acceptance, will generally not have a negative impact on the house. On the contrary, it can protect the roof and provide insulation and cooling. However, if unprofessional construction, illegal installation, or blind installation on old houses occurs, various problems will arise. This article addresses the four most concerning issues: load-bearing capacity, waterproofing, safety hazards, and house damage, providing a comprehensive explanation to help you avoid common installation pitfalls.

This is the biggest concern for all homeowners, especially those with self-built houses in rural areas, old bungalows, and old-style tiled houses. We can clearly tell you: a properly installed solar PV system has a load capacity far below the roof's load-bearing standard and will not collapse the roof.

A complete residential photovoltaic (PV) system, including PV panels, brackets, fasteners, and cables, is extremely lightweight: a typical monocrystalline PV panel plus an aluminum alloy bracket weighs only 8-12 kg per square meter, far less than the weight of bricks, cement, and roof tiles. Compared to the roof load from daily snow accumulation, heavy rain, and typhoons, the load on the PV system is negligible.

• Cast-in-place concrete flat roofs: These have the strongest load-bearing capacity, fully meeting the requirements for PV installation. They bear no load and are the optimal roof for installation.
• Glazed tile and pitched tile roofs: Suitable for standard, qualified self-built houses and commercial housing roofs. The brackets distribute the load point-to-point, preventing concentrated pressure on any single area.
• Old, dilapidated houses, simple corrugated steel sheds, and wooden roofs: Direct installation is not recommended. Load-bearing testing and reinforcement are necessary beforehand to avoid the risk of deformation and collapse over long-term use.

A standard installation process begins with a load-bearing survey. Professional engineers calculate the load based on the building's age, roof structure, and building materials. Only after meeting the standards will an installation plan be designed, eliminating potential load-bearing hazards at the source.

Many people have heard that "roofs leak after a few years of solar installation." However, the core reason for leaks is not the solar panels themselves, but rather improper construction and inadequate attention to detail. A properly constructed solar system not only prevents leaks but also extends the lifespan of the roof's waterproofing.

• The construction team drills holes directly without waterproofing or sealing, allowing rainwater to seep into the walls through these holes;
• Tiled roofs are not properly repositioned after tile removal, and gaps are not sealed;
• Improper bracket spacing leads to poor drainage and water seepage;
• Inferior waterproofing adhesives and sealing accessories are used, causing them to age and detach quickly.

A professional photovoltaic installation team strictly adheres to waterproofing construction standards: after drilling, a triple protection system of waterproof base, sealant, and waterproof gaskets is used, with all perforation points fully covered by waterproofing. For tiled roof installations, the principle of "fewer holes, stable fixing, and tight sealing" is followed. A drainage test is conducted after completion to completely eliminate the risk of leakage.

Photovoltaic panels covering the roof surface are equivalent to adding a "protective layer," directly shielding the roof from sunlight, heavy rain, and frost, reducing the aging rate of the roof waterproofing layer, tiles, and cement layer, effectively extending the roof's lifespan by 3-5 years. They also lower the roof temperature, achieving indoor heat insulation and cooling.

Photovoltaics are a mature new energy device and have no inherent safety hazards. All risks stem from inferior products, improper construction, and neglect of maintenance. Common potential hazards and solutions are as follows:

• Hazard of being overturned by typhoons and strong winds: Some low-cost installations use thin-walled, inferior brackets with insecure fixing, which can easily lead to bracket loosening and component detachment during strong winds. Solution: Use national standard aluminum alloy/hot-dip galvanized steel brackets, design fixing points according to local wind pressure, and avoid shoddy workmanship.
• Hazard of leakage and fire: Use of off-brand photovoltaic panels, inferior inverters, haphazard wiring, and aging or damaged cables can cause leakage, short circuits, and even fires. Proper installations use brand-compliant equipment, equipped with leakage protection, lightning protection grounding, and overload protection devices, with standardized wiring throughout, eliminating electrical safety risks.
• Hazard of snow accumulation and falling objects: Heavy snow accumulates on the surface of photovoltaic panels in winter, and improper installation angles can cause snow to slide off. Professional solutions adjust the component tilt angle according to the local climate, leave space for drainage and snow removal, and ensure edge protection to avoid the risk of falling objects.
• Potential Risks of Overheating and Module Burnout Due to Obstruction: Tree branches, debris, and roof protrusions can obstruct photovoltaic panels, leading to hot spot effects and potential damage from prolonged high temperatures. During installation, obstructions are cleared beforehand, modules are strategically arranged, and maintenance and ventilation space is provided.