If the final test is to be made with peppermint, a mixture of 2 ounces of oil of peppermint to a gallon of hot water is the requirement for an ordinary house.
On large work, 2 ounces of peppermint should be used for each stack up to five stories and basement in height, and for each additional five stories, or fractional part of that number, an additional ounce per stack. The peppermint should be poured into the roof opening and the opening sealed. The person who has handled the peppermint should not enter the building until the test has been completed, as the odor which he carries will spread about the house.
Peppermint has a very penetrating odor, and its fumes quickly reach every part of the system, and by their escape bring attention to defects. A great point against the use of peppermint is that through a large defect the peppermint will pour in sufficient quantity to quickly fill the house with the odor, making it difficult to locate other leaks. Under certain conditions, however, the peppermint test seems to be the more reliable.
For instance, on old work, much of the soil piping is often buried underground. In the event of defects underground, the peppermint fumes will often penetrate through into the cellar, whereas smoke would not.
At the present time there are comparatively few towns of size, or cities, which do not demand the testing and inspection of the plumbing system, and, without doubt, no other factor has resulted in an equal amount of good in the attainment of sanitary work.
Such provision makes it far more difficult for work to be constructed of inferior material and with wrong connections, as between the testing and inspection of the system many of these features are discovered.
The result of inability under the circumstances, to provide such regulation, results in the construction of a considerable amount of poor and unsanitary work in the country.
This condition has been much improved in recent years, however, chiefly through the demands of owners for tests to be made in the presence of architect and owner, and through the effort of many architects to demand these things in their specifications.