When building bunds it is important to realise that they will need to be tested every three years (for example if your have an IPPC or Waste licence issued by the EPA) and that this testing is by means of a water retention test.  If the guidance offered by either the EPA or CIRIA 163 is followed there will be no problem.  However, most bunds fail due to this guidance not being followed.  The following is therefore an overview of the common errors made in bund construction.

Most authorities state that bunds should be constructed of reinforced mass concrete (RMC).  Our experience is that these bunds have the lowest failure rate.  However, many bunds in Ireland are built of concrete blocks, sometimes with a render of cement on one or both sides.  At first sight block built bunds with cement render can look like RMC but the cement render will have a coarse surface, whereas a RMC bund has a smooth surface.  Block built bunds can leak water between the blocks and this is a common failure mode.

Many block built bunds are built using an existing building wall as the back wall.  This would appear to be cost effective at first sight as the building wall already exists.  However, these bunds invariably fail on testing as the water pressure moves the bund wall away from the building wall and the water will leak from this joint.

Another common fault with block built bunds is that they will often crack due to ground movement, especially where the walls are long.

If you need advice on bund construction or design of bunds, please contact us