Why the Right Cable Gland is Crucial
When installing photovoltaic systems on pitched roofs, solar technicians and electricians face a central challenge: how do you safely and permanently route the PV cable through the roof covering into the building's interior? Improper routing can lead to moisture damage, heat loss, and long-term problems with the roof structure.
In this guide, you will learn which methods have proven effective in practice and why specialized roof penetrations made of UV-resistant plastic are the most efficient solution for professional use.
The Challenge: Routing PV Cables Through Roof Tiles
Solar cables must be routed from the roof into the building's interior – this applies to both large PV systems and balcony power plants. The following requirements apply:
- Watertightness: The penetration must not impair the rain resistance of the roof covering
- UV Resistance: The material must withstand years of sun exposure
- Cable Protection: Sharp edges on roof tiles can damage cable insulation
- Easy Installation: The faster the installation, the more economical the job
Method 1: Drilling Through the Roof Tile
Some installers drill a hole directly through the roof tile. We advise against this – the tile is weakened, cracks can occur, and watertightness is not permanently guaranteed. Furthermore, the effort for drilling and sealing is disproportionately high.
Method 2: Routing the Cable Under the Roof Tile
A common practice is to route the cable under the edge of the tile. The problem: the tile no longer lies flat, gaps form, and the cable is mechanically stressed with every gust of wind. In the long term, this can damage the cable insulation.
Method 3: Using a Special PV Roof Penetration (Recommended)
The most professional solution is a specially developed roof penetration for PV cables. This is installed instead of a roof tile or additionally under a tile and provides a defined cable duct with abrasion protection.
Advantages of a Dedicated PV Cable Penetration
- Precise integration into the roof covering
- No drilling, no cutting – tool-free installation possible
- UV-resistant technical plastic for long service life
- MC4 connectors can be routed through without disassembly
- Defined bending radius protects cable insulation
Step-by-Step: Installation of a PV Roof Penetration
- Determine position: Choose the point where the cable is to be routed into the roof interior – ideally near the inverter location
- Lift roof tile: Carefully lift the relevant tile and the tile above it
- Insert roof penetration: Place the penetration on the batten and slide the tile back over it
- Route cable: Route the solar cable through the cable duct – with suitable models, even with the MC4 connector already installed
- Visual inspection: Check that the tile lies flat and no gaps are visible
What to Look for When Buying
Not every roof penetration fits every roof. Please note the following points:
- Tile type: Frankfurt pan, beaver tail, or other roof tiles – the penetration must match the tile shape
- Cable diameter: Standard solar cables (4–6 mm²) up to earthing cables (16 mm²)
- Length of the penetration: Depending on the roof structure, models with 105 mm, 125 mm, or 150 mm length are required
- Number of cable ducts: 2-way or 4-way penetrations for different requirements
- Material: UV-resistant technical plastic is ideal for permanent outdoor applications
B2B Volume Prices for Solar Technicians and Electricians
For commercial customers, we offer attractive volume prices. The larger the purchase quantity, the lower the unit price. Our PV roof penetrations are available in packs of 10 or more – ideal for companies that regularly install PV systems.
All roof penetrations are manufactured in Germany and shipped directly from stock. We deliver quickly and reliably – even large orders.
Contact us for a customized offer: info@dachdurchfuehrung24.com or by phone at 07054 927999.
Frequently Asked Questions (FAQ)
Can I route MC4 connectors through the roof penetration without disassembling them?
Yes, our roof penetrations are dimensioned so that MC4 connectors can be routed through without disassembly. This saves time during installation and avoids potential contact problems due to re-crimping.
Which roof tile types are the penetrations suitable for?
Our roof penetrations are optimized for common pitched roof tile shapes, especially Frankfurt pan and comparable concrete roof tiles. Please note: The products are designed exclusively for pitched roofs with tile coverings.
How many cables fit through one penetration?
Depending on the model, you can route 2 or 4 cables simultaneously. For a typical balcony power plant installation, a 2-way penetration is sufficient. For larger PV systems, we recommend the 4-way version or multiple penetrations.
Do I need tools for assembly?
No, assembly is tool-free. The penetration is simply pushed under the roof tile. No drilling, sawing, or gluing is required.
The suitable PV cable roof penetrations for mechanical abrasion protection can be found in the D24-B2B-Shop (volume discount from 20 pieces) – UV-resistant TPU, Made in Germany.
