Gigantic renovation of a roof in Radomir, Bulgaria

Bulmachinery Enterprises Ltd. produces for the investment goods sector (mechanical and plant engineering), e.g. mining and mechanical engineering, power generation, cement and manufacturing industry, ferrous and non-ferrous metallurgy, crane construction and port facilities.

The factory building in Radomir, Bulgaria was constructed in the 1980s. This building was designed to meet the production requirements for the various industries and, to this day, its architecture remains unique in southeastern Europe.

​After more than 35 years, leaks began to appear at different places on the roof. Once this state of affairs had worsened to the point that after «each rain there would be a couple days of more rain», as the foreman at «Bulmachinery Enterprises» put it, a complete renovation became urgently necessary.

Leister makes sure that heads are dry 
This large-scale order was then assigned to Firma VJF Ltd., a specialist company with 20 years of experience in the area of waterproofing and innovative building solutions. VJF lays particular emphasis on quality and safety in it projects. It was for that reason that LEISTER and a high-quality 1.2 mm TPO (thermoplastic elastomer) material were selected for this job.

Leister maintains sales and service points on site in Bulgaria, just as it also does on 130 other countries. Here it is represented by KOBO BG Ltd. in Sofia, which has been representing VJF Ltd., the specialist in sealing systems, since 2005.

Mastering the great challenge
This was certainly the largest order that «VJF Ltd.», a long-established company, had carried out to date: after all, a 10-hectare (21.7-acre) roofing project is not something that comes along every day.

The following Leister Tools were used for the project, which took more than five months to complete: one VARIMAT V2, two VARIMAT V2, one TRIAC Drive and more than 15 hot air hand tools (TRIAC AT and TRIAC ST).

The 100,000 m² roof, comprised of two parts, was rapidly and economically lap- welded with 1.2 mm TPO, for which the Varimat V2 reached a speed of 2.8 to 4.6 m/min at 460°C, while the Varimat V clocked in at a speed of 1.8 to 2.5 m/min at 450°C.

The TRIAC Drive, the only semi automatic welding machine from Leister, welds smaller areas, where no other welder can reach, quickly (three times as fast as a conventional hot air hand tool) and cleanly. The Leister Hand-Tool product range was responsible for the fine-tuning. The reliable EXAMO USB was used to check the material for absence of leaks.

Finally, an absolutely leak-free roof 
Despite the tight schedule, the mega-project was able to be completed on time. This was mainly thanks to the efficiency and the simple handling of the Leister VARIMAT V2 & VARIMAT V. The TRIAC Drive, Leister›s «all-rounder» when it comes to roofs, convinced by its flexible concept and reliability.

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Leister Sales and Service Center: KOBO BG Ltd. 
Customer: Bulmachinery Enterprises Ltd 
Material: TPO Membrane
eister Products: VARIMAT V2, VARIMAT V, TRIAC AT, TRIAC ST, TRIAC S 
​Text / Photos: Leister AG and KOBO BG Ltd.