Project Description

The elevated drinking water tanks at Kunigundenruh were built in 1968 (2 x 5’600m3, 1 x 12’000m3). The concrete structure was sealed internally with an epoxy coating and only one year later, due to some leakage, it was additionally lined with a loose laid welded PVC sheet membrane system. After more than 36 years, this membrane had finally become brittle due to loss of plasticizers, some cracks had developed in its surface and it had started to leak.

This allowed water ingress to the reinforced concrete structure, especially at the floor to wall joints and also at the intersection with the structural steel support structure. In these areas the concrete had suffered spalling around the corroding steel and it needed to be repaired.

Consulting Engineer: BAURCONSULT Architekten und Ingenieure, DE- 97437 Hassfurt
Contracter: Von der Forst GmbH, DE - 96176 Pfarrweisach

Project Requirements

For the project study the engineer received the order from the owner to analyze the two most appropriate solutions for this water Tank refurbishment.

Option 1 was a mineral-based thick coating system and Option 2 was a Sikaplan® sheet membrane system. This was eventually selected for the project because of the following important advantages:

  • Secure watertight treatment of the movement joints without reducing their movement capability
  • No need to remove the existing epoxy coating
  • Good crack bridging abilities
  • Good price performance ratio – a system with a long life expectancy
  • The possibility to remove any trapped moisture and condensation water from behind the system at any time to prevent it damaging the structure

Sika Solutions

The two 5600m3 tanks were refurbished in 2006, using Sikaplan® WT 4300-15C Felt, laminated with a 500 g polypropylene felt to provide the rear drainage, membrane protection and Velcro fastener installation. The third and largest 12’000 m3 tank will be refurbished with the same system shortly

Sika Products

In addition the following Sika product was used in the project

  • Sikaplan® WT 4300-15C Felt

Check out more information about Sikaplan products in the German market