With a population of over 8.17 million people, the city of London, England continues to grow. The most recent census, released in 2012, reported a population increase of 12% over the past 10 years. This makes London the fastest growing city in England.

The population boom has contributed to an increased population density, with limited space for building new homes. With no room to grow outwards or permission to build upwards, many people outgrowing their current homes have chosen to expand downward, creating subterranean extensions which can sometimes triple the size of the street level home. In the Belgravia district of central London, one such home faced the difficult task of constructing their 8 metre (26.25 foot) deep basement through water saturated sands and gravels into heavy London clay. Another challenge was building the basement with underpinning retaining walls, spanning 7.5 metre (24.6 foot) vertically, in permanent condition.

The engineering firm taking on the project was Abbey Pynford, a dynamic Ground Engineering Solutions Company with considerable expertise in the complex fields of foundations, underpinning and piling. Using their experience and expertise in similar situations, they opted to use Kryton International Inc.’s concrete waterproofing products to permanently protect the concrete structure from water ingress.

“The flexibility and workability of the Kryton product range enabled a number of construction techniques to be employed which best suited the ground conditions and engineering requirements for each element of the project,” says Abbey Pynford divisional manager Lewis O’Connor.

The basement was constructed using Kryton‘s Krystol Internal Membrane concrete waterproofing admixture and Krystol Waterstop System,  a two-layer joint protection system.

The Kryton system creates two layers of protection for the joints, with the second layer constructed from inside the completed structural shell of the basement. This increases quality management as the environment is controlled to be relatively clean and dry. The joints can be inspected pre- and post-grouting and any defects fixed.

Mr. O’Connor adds “The Kryton products facilitated a very high degree of construction quality assurance, not possible with other products in the same circumstances.”