Grondslag, an independent consulting and inspection firm with more than 30 years of experience, is joining the Sansidor network as of May 22, 2025. With this move, the company will continue to operate independently while becoming part of a growing network of Test, Inspection and Services (TIS) specialists.
Grondslag has offices in Kamerik, Heerhugowaard and Steenijk and has built up a solid reputation as a reliable partner in soil investigation, road construction advice, remediation supervision and safety advice, including soil remediation. The company works for a wide range of clients, including engineering firms, contractors, environmental services and government agencies.
Pieter de Vries, founder and former Managing Director of Grondslag: “Grondslag is a big part of my life. I am proud of what we have built together. After years of growth, I felt it was time for a new phase – for the company and for me personally. With Rob and the team, the company will be in trusted hands, and within Sansidor there will be room for new development without losing our independence.”
Rob Groot, new Managing Director, adds: “We will continue to do what we do best – with the same people, the same locations and the same customers. But now with the ability to work together with other specialists within the group as well as use central support in areas such as IT, HR and marketing.”
With the affiliation of Grondslag, Sansidor is strengthening its position in the physical environment. Together with another party, Grondslag forms the core of the new Soil, Infra & Environment cluster within the network. This creates more scope for services in the field of soil research, infrastructure, permit processes and environmental issues.
Udo Waltman, CEO Sansidor: “Grondslag is a wonderful addition to our network. Their expertise, approach and culture fit what we want Sansidor to be: a group of strong companies that remain independent, but together make more possible. We look forward to what we will achieve together.”
The new MT looks forward to this next phase in the existence of Grondslag – together with their colleagues, clients and partners – with confidence and great enthusiasm.
About Sansidor
Sansidor is a rapidly growing network of testing, inspection and services (TIS) companies. Its focus is on safety, health and sustainability in buildings, installations and infrastructure. By adding companies that maintain a high degree of independence, Sansidor creates a strong platform for collaboration and knowledge sharing. This model – “Buy and Build together” – is an investment by IK Partners and HC Partners. Sansidor’s motto is: Ensuring a safe and healthy environment.
