Sika is a leading provider of solutions for the protection and repair of building structures. Philippe Jost, Head Construction and Member of Group Management, explains in this interview why the long-term preservation of buildings promotes sustainability, and how Sika researches the aging processes of building structures.

Why is it important to promote the longevity of building structures?

Various studies show that extending the life span of a building or structure by 20 years has the effect of reducing the cumulative CO2eq kg per m2 by 30%. In other words, extending the lifecycles of buildings is important if a positive sustainability effect is to be achieved. This in turn can be accomplished by durable solutions and increasing longevity. Greater awareness of the negative consequences of climate change and the scarcity of resources will result in more stringent sustainability standards and promote a holistic view of building lifecycles. Developers, investors, and owners will also increasingly realize that longevity can make a key contribution to sustainability.

Head Construction

Philippe Jost, Head Construction and Member of Group Management

How does this have the effect of reducing greenhouse gases?

Extending the lifecycle of a building is key to making CO2 savings, as the resources employed can be used for longer and unnecessary CO2 emissions are avoided. A further plus is that it is obviously commercially worthwhile, too, as it means that investments can be amortized over a longer timeframe.

What external influences are buildings particularly exposed to?  

Broadly speaking there are two problem areas: on the one hand mechanical wear – abrasion – and on the other aggressive substances such as chloride and CO2 attacking concrete.

What solutions does Sika offer to protect buildings against these influences and extend their lifecycles?  

Sika offers a broad spectrum of protection and repair systems for reinforced concrete that have proved themselves over many decades. Among other things, our product range includes high-quality concrete admixtures, specialty mortars, waterproofing membranes, and systems for static strengthening and concrete protection.

How does Sika differentiate itself from its competitors in the area of longevity?

Not all competitors can offer a product portfolio that is as broad as ours. What’s more, we have a number of solutions that exhibit superior properties. Other strengths of Sika include the power to innovate, proximity to the customer, and an understanding of local practices.

Is the importance of building longevity to climate protection and the saving of resources also now evident to developers and owners? 

In Europe, yes, but in other parts of the world the degree of awareness is not yet quite so pronounced. Developers, investors, and owners tend not to take such a long-term view when planning. In North America, for example, no one builds a house with 20 years in mind. The mentality is more buy and sell – with a higher focus on the price in the knowledge that problems may come to light at an earlier stage. That said, we are seeing an increase in awareness in many countries.

Bridge in Klosters Switzerland
How else could longevity be further promoted in the planning, maintenance, and repair of buildings?

There need to be incentives for developers to invest in longevity. The public sector could also lead by example and factor the aspect of longevity into tender procedures – as was the case for the awarding of the contract for the new Gotthard Base Tunnel, for example. For this project, a life span of 100 years was stipulated. We are increasingly seeing requirements of this type in other countries too.

But is the requirement for a structure to last for a whole century realistic? Can companies really give a guarantee of this kind?

It’s not so much a question of a guarantee as life expectancy. The requirements are very diverse in this area, and can range from 20 years to 100 years, depending on the product. Here companies rely on scientific tests that simulate the aging process.

Sika is continuously developing new solutions. What direction is research taking in the area of longevity?

Essentially we are very interested in the aging processes of building structures. This is a theme that we are permanently investigating and researching. The first step is for us to understand which aspects are crucial for the longevity of a building structure. Based on the corresponding findings we then improve and adjust weak spots in order to be able to guarantee and extend the longevity of structures. What specific influences negatively impact durability will depend on the individual product. In the case of a waterproofing membrane for a flat roof, for example, UV stability really matters, whereas the crucial thing for mortar used in wastewater tunnels is resilience against biogenic sulphuric acid corrosion. And when it comes to protecting bridges, the most important factor is the ability of repair mortars and concrete admixtures to withstand the influence of salt water.