Oakum
Oakum is a preparation of tarred fibre used to seal gaps. Its main traditional applications were in shipbuilding, for caulking or packing the joints of timbers in wooden vessels and the deck planking of iron and steel ships; in plumbing, for sealing joints in cast iron pipe; and in log cabins for chinking. In ship caulking, it was forced between the seams using a hammer and a caulking iron, then sealed into place with hot pitch.
Tie (cavity wall)
Due to its materiality of the tie, its corrosion is related to the extent of the exposure at acidic substances. The major factors of the corrosion is these:The cement-based mortar, giving an alkaline environment for cavity wall ties, has been used after World War II. Alkaline environment is beneficial for ties protecting from acid and procrastinating the corrosion process. Before cement-based mortar, lime-based one was used, which does not present an alkaline environment. Therefore, the majority buildings with wall tie corrosion are built before World War II. An alkaline degree gets weaker while exposed at acidic rain over the time.