THE SOLUTION
We were contacted to see if we could develop a solution to seal the weir externally in order to avoid removing the weir with craneage.
The works had to be completed in December which presented challenges with regard to climatic conditions as required for most sealing and coating materials.
Sealing externally is always challenging as the negative pressure applies a load force against the applied sealant – meaning that any sealing solution must have sufficient adhesive, cohesive and tensile strength to resist this force.
We proposed a multi stage sealing solution, finishing with the application of PPG Raven 405. The reasons for proposing this material are as follows;
- Excellent adhesion to damp substrates, with no dew point or humidity restrictions
- High Tensile Strength
- Designed and proven to withstand negative water pressures
Initially where possible any failed butyl sealant was removed. This was followed by the preparation of the steel and concrete by method of water entrained abrasive blasting.