A new way of bringing old buildings back to their best

The EUREKA network project HERIFUND brought Slovenian Construction Engineering Company ING.KLAN and German company Ipa Bauchemische Produkte GmbH together with the aim of tackling bad practice in the restoration industry and to revolutionise the approach to how we treat old buildings.                                                              

“Dampness is one of the biggest problems we face in historical buildings,” says ING.KLAN’s Chief Engineer Ivan Klaneček. ”By their very nature built a long time ago, the reason that old buildings are not more water-resistant is that the technology to waterproof them and to build proper foundations was not advanced enough when they were constructed.            

“Historical buildings were very often built either without any foundations at all, or with very shallow foundations,” Ivan continues. “And without a proper foundation to protect the building from direct contact with the earth, moisture in the soil has very easy access to the building. Water will flow up into the walls through cracks and pores and become trapped there. And so as well as making the building very cold, a physical-chemical process we call ‘carbonation’ takes place.”

Carbonation happens when carbon dioxide enters the walls of the building and reacts with the concrete and with the moisture trapped within it. The chemical reaction which comes about from this interaction reduces the ability of the construction materials to neutralise acid.

“Simply put,” Ivan says, “this entire process ultimately leads to cracks in the walls making the building unstable. So it’s the combination of both of these problems that can make historically important buildings extremely vulnerable.”

But until now, the proposed solutions to the above problems have always fallen short. For example, construction workers might knock the offending wall in order to insert hydro insulating implants at its root. Although this does prevent moisture from entering, and therefore prevent cracks, it’s a time-consuming approach and can be damaging to the building and the environment.

Another method sees workers excavate around the wall and create a foundation in buildings where there are none already existing. This approach of under-excavating and building missing foundations can be damaging to the building and is also extremely expensive.

Faster, cheaper and environmentally friendly

“What we propose with HERIFUND addresses all the problems that have been plaguing this industry for decades,” says Ivan. “With our approach, which is now patented worldwide, we drill tiny bores into the existing construction. Then, using probes or valves, we waterproof the building. Once this is done, we inject an expansive compound called silicate grout through the bores. This is a new, environmentally friendly and long-lasting mineral which expands into the cracks and pores in the walls and does two things at once. It stabilises the building by filling the potentially destructive cracks. And it insulates the building from water damage, making it warmer and saving energy.”

Because there is no need to knock any walls, this approach takes less time and therefore costs less money. And because of the unobtrusive nature of the approach, there is far less scope for environmental damage. As the approach gets rid of trapped moisture in the walls, the building will become naturally more energy efficient.

German partner Ipa Bauchemische Produkte GmbH was involved in the material development, and the Slovenian partner ING.KLAN tested and applied the material. Enhancement of the material to be used on the one side and the refinement of the application method on the other side led to benefits for both partners.

“The results we got from testing during HERIFUND were excellent and confirmed everything we had hoped about our new approach. We now have our own school which trains people how to use the new technology and have received numerous awards for this system in Europe, Asia and the US. Many partners are already benefiting from our work and as more and more satisfied customers continue to spread the word, we’re sure our technology will soon take off in a big way,” says Ivan. 

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