SIEVERT - Thermoweld 40 400V | Automatic Welder

✔ 40 mm professional automatic welder for PVC & TPO: perfect for precise overlap seams on flat roofs
✔ Constant temperature up to 620 °C: exact control for secure, reproducible seams
✔ Infinitely variable speed: 0.5–14 m/min for maximum control depending on the material
✔ Robust & construction site-ready: 42 kg dead weight plus additional weights for optimal contact welding pressure
✔ Design & Made in Europe: Developed in Sweden 🇸🇪, manufactured in Switzerland 🇨🇭: uncompromising quality for professional roof waterproofing

Your welding professional for secure PVC and TPO seams

With the SIEVERT Thermoweld 40 400V automatic welder, you are getting a genuine professional tool if you want to weld roofing membranes cleanly, tightly, and permanently – without any guesswork, just maximum process reliability. Especially on large surfaces on flat roofs, consistent seam quality is crucial: constant temperature, stable movement, and controlled contact pressure. That is exactly what the Thermoweld 40 is built for.

The automatic welder works with a 40 mm welding width and is ideal for PVC and TPO membranes. You can set the temperature, air volume, and speed to precisely match the material, substrate, and weather conditions. This allows you to achieve reproducible results – from the first to the last strip. Compared to a hand burner or manual hot-air welding, you save time, reduce sources of error, and noticeably increase seam security.

Everyday use in roofing

You position the Thermoweld automatic welder along the overlap, align the machine cleanly with the seam guide, and select the parameters based on the membrane and outside temperature. The welding process then runs in a controlled manner along the length: hot air activates the surface, and the defined contact pressure connects the layers reliably.

For details, connections, or tight areas, you can effectively combine the machine with hand tools – e.g., a suitable burner/hot-air tool, pressure roller, and seam tester. This makes the Thermoweld a strong component in modern roofing supplies and a genuine efficiency booster on the construction site.

Important technical details

• Voltage: 400 V
• Power: 5,500 W
• Welding width: 40 mm
• Temperature range: 20–620 °C
• Air volume: 250–500 l/min
• Speed: 0.5–14 m/min
• Weight: 42 kg
• Cable length: 5 m (CEE 16A)
• Application area: PVC and TPO roofing membranes

Order now in the roofing shop

If you are looking for a robust roofing tool for precise seams, you will find the Thermoweld 40 400V in the roofing shop at your roofing specialist Roofify – for professional waterproofing that counts on the roof.

Video: Sievert Thermoweld - Next Generation Welding. Simplified.