Flooding – Resilience and Repair


There is little solace for the thousands of property owners whose homes or business were devastated by the widescale flooding in the mid summer of 2007. Whether caused by freak conditions relating to climate change, lack of investment in flood prevention measures or antiquated drainage systems ill equipped to handle the scale of homes built, is of scant relevance.


There is a study programme to meet the challenge for resistance and resilience of buildings headed by a CIRIA consortium and advised by steering and advisory groups of funders and other stakeholders. Its aim is to determine how the implications of flooding may be mitigated by best practice in material selection and construction techniques and that by laboratory and field testing their findings should influence building regulations.


Amongst the many practical and innovative inventions that are available to achieve this goal, one contributory solution identified by the programme is hydraulic lime. Before the technology for kilns was available to fire limestone/clay to temperatures >1450°C to create modern day cement, lime was the binder relied upon in the construction of our heritage.


For property owners and for the institutions responsible for aiding them in their recovery from the effects of the flooding, hydraulic lime represents a repair and a cure. Hydraulic lime mortars will assist in stabilising a saturated existing structure. They will allow the moisture to escape as a vapour over the years that it will take for its extraction from solid masonry walls. Formulated self flowing grouts for rubble walls undermined by flowing water and salt resistant mortars can ensure that water will not enter the walls again. If flooding should re-occur the mortars will not deteriorate and will dry out without detrimental effect other than to decoration, a far more tolerable effect than structural remediation.


Unilit natural hydraulic lime has been successfully used in the remedial process and benefit has been gained by the increased awareness of a natural process for repair that will offer resilience should events repeat and offer best economical value.


For modern methods of construction a combination of Foamglas™ recycled cellular glass insulation and hydraulic lime have been tested at the Taylor Woodrow Laboratories as an insulated cladding developed under a collaborative agreement with Pittsburgh Corning (PC UK) to provide a render system with unique characteristics.


Sustainability of source, maximised use of recycled materials, resilience to flooding, non combustibility, strength, water resistance, durability and ease of installation in an on or off-site condition are priorities applied to these tests.


In addition to gaining CWCT certification the system was subjected to a unique evaluation to establish the resilience of the system to flooding when applied upon a panel of lightweight steel walling immersed under a one metre head of water for a 72 hour period.


The re-emergence of natural hydraulic lime as a traditional mortar capable of meeting the challenges of new construction is gaining strength.


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