Founded in 1918 by Walo Bertschinger, WALO has been providing hydraulic asphaltic barrier systems for the containment of water all over the world for more than 60 years. The WALO group is still wholly owned by the Bertschinger Family. Its UK arm, WALO UK Ltd, a wholly owned subsidiary, is based in Stafford.

Specialising in providing hydraulic asphaltic barrier systems for the containment of water, with particular expertise in providing lining systems made from Dense Asphaltic Concrete (DAC), WALO provides impermeable barrier systems all over the world for a large range of applications including dams, reservoirs, hydro-electric infrastructure, artificial lakes and ponds and landfill sites.

WALO has world-leading technical engineering expertise and the necessary specialist plant and equipment to provide a Dense Asphaltic Concrete (DAC) impermeable barrier system anywhere, for any situation. DAC is ideal for hydraulic engineering projects, providing a highly robust, non-toxic lining, which is thin enough to flex under extreme pressure without cracking but still quick to lay, even on very steep slopes and totally safe for human, animal and marine life – making it ideal for water storage. Due to its high density, DAC is extremely resistant to chemical attack while being very strong and flexible.

WALO's DAC lining system, made from clean aggregates, fillers, sand and bitumen, is installed using the company's specialised laying and compaction techniques. Long, near vertical slopes can be constructed using WALO's specially engineered equipment and DAC. Any joints required are made strong and totally impermeable by the special treatment and compaction methods employed.

WALO provides lining systems of every size from relatively small projects to major hydro-electric plants and reservoirs. As well as new constructions, WALO is often called upon to carry out remedial work on existing structures. As with all highly loaded and stressed construction structures, asphalt linings are also subject to natural ageing. This, combined with inferior paving equipment and lining systems deployed, sometimes results in the reconditioning of projects from the 1950's and 1960's. Typical signs are blisters and an imperfect connection between the two layers. Quite often only partial rehabilitation is required i.e. the treatment of isolated areas or just the top surface of the sealing system. In each case the volume and depth of works has to be studied and defined for each individual project. In many cases only the top layer of the sealing system has to be replaced due to the fact that this surface is mostly exposed to external stresses.

WALO provides a complete service to its customers – from initial feasibility studies to designing, manufacturing and installing suitable materials to match their individual requirements for sealing systems in every kind of hydraulic application. To find out how WALO can provide the perfect hydraulic engineering solution for you, please contact David Wilson, Managing Director on +44 (0)1785 719793 or email