HydroFoamer is a self-contained, portable automated spray platform that very rapidly apply a layer of closed-cell, rigid polyurethane foam to a pipe system.

Applying a layer of PU foam to the pipe allows the pipe to be backfilled with native soil, rather than imported or locally-crushed granular backfill.  

The PU foam is extremely stiff and impermeable.  It has the material properties to protect the pipe mechanically and chemically from native soils and cathodic potential, while the effect of the layer of foam makes a single, stiff system that affords huge multi-axial, geodetic stability.   The cellular structure of PU foam makes it a perfect load-spreader, which stops ovalling and allows cheaper pipe materials with lower ring strength, such as HDPE, to be considered for projects.

The effect of all this is to reduce the time and cost of installation, while producing a system that doesn’t need concrete thrust block anchors to counter powerful resultant bend forces.

The system was originally designed for GRP pipe installation in hydropower projects, but is equally applicable to metal and polymer pipes, such as HDPE, in all sectors that use buried pipe systems: oil & gas, water, sewage, etc.

Academic & Technical Validation

The commissioning of Lille Måsevann penstock proves that the method with PU-foam as backfill works on a full-scale project, both for construction and operation.

Prof. Leif Lia – NTNU Trondheim

We have followed a strategy of seeking independent academic validation of the engineering model, by bringing together NTNU, the world’s top hydropower university, with Norway’s premier civil & hydropower engineering firm, Multiconsult.

3 masters degrees have been completed on the PU foam backfill concept, and Professor Leif Lia has publicly stated that the system is ‘fit-for-purpose’.

The first installation project was carried out for Statkraft, the Norwegian state’s hydropower giant, in 2016. 3 seasons of production show perfect results: the system performs even better than Multiconsult predicted.

The method is suitable for all risk-classes.


You can download Professor Leif Lia’s 2018 presentation to ICOLD in Vienna from here.