We have been producing hot air products for industrial needs for more than 45 years.



Powerful welding machine for roof welding and overlap welding

Cost-effective and user-friendly welding machine

Infinitely adjustable temperature

Produced in Germany


The Forsthoff-D roof welding machine is the optimal welding machine for welding thermoplastic roofing membranes. This apparatus is also suitable as an automatic overlap welding machine for welding heavy thermoplastic tarpaulins and foils.

The Forsthoff-D produces overlap seams of either 40 mm or 45 mm. The heating power of 4000 W 230 V is infinitely variable from 20 – 700 °C and can thus be individually adjusted to the different materials. The mounted powerful hot air blower Oval-AB produces a strong air output of 360 litres/minute.

In addition, the Forsthoff-D machine offers an advanced geared motor from Germany. Thanks to the infinitely variable speed setting, a speed of up to 16 meters/minute can be achieved.

In conjunction with the holding-down device for crease-free welding, the tarpaulin and roof tarpaulin processor obtains an optimum welding result. The apparatus starts up automatically after the welding head has been pivoted in. A three-point support also guarantees the tarpaulin’s secure pressure. This is additionally supported by the weight of the FORSTHOFF-D machine, which is integrated into the housing of the welding machine and can be removed if required.

Technical specifications






50/60 Hz


20 - 700°C


Length 520 mm, width 385 mm, height 320 mm (without guide handle)


30.5 kg incl. weight and handle

Conformity mark


Protection class:

II / 


Item no. 12910P2

Overlap welding nozzle 40mm

Item no. 1117P2

Overlap welding nozzle 45mm

Item no. 1119P2

Roof welding nozzle 40mm

Item no. 1118P2

Roof welding nozzle 45mm

Item no. 1114P2

Nozzle adjustment gauge

Item no. 3059

Heating element 230V 4000W

Application areas

Flat roof membrane welding and Pitched roof membrane welding

Bitumen welding

Swimming pool construction

Pool waterproofing

Pond film processor

Tarpaulin manufacturer

Manufacturers of tents and tarpaulins

Produced in Germany