Problem
The building would be modified into modern educational facilities. The goal was to improve the indoor air while keeping the original building structure intact.
There were several large cold rooms that had been used to store biological material. The wall and ceiling had previously been treated with a tar product as a capillary barrier.
Since it is virtually impossible to get rid of tar smell by removing tar from a concrete surface one would have to remove a considerable amount of concrete.
Measure
cTrap was installed on the floor, wall and ceiling.
The rebuilding of the building could continue and there was no smell in the modified parts of the building.
cTrap was subsequently covered with a thin plasterboard (on ceiling and wall) and new flooring.