BUILDING STONE - 



BUILDING STONE 



As only a few of the members can borrow 

 the accumulated capital at any one time, the 

 others must continue their payments, with the 

 idea that they will borrow at some future time. 

 Members are always allowed to withdraw, but 

 few of them do so, as they then lose a part of 

 the savings already invested in the shares. Ob- 

 jection has been raised to such organizations 

 because they charge high rates of interest on 

 their loans. But it is true that they lend 

 money to people who would not otherwise be 

 able to own their homes. In most of the states 

 and provinces, as well as in many European 

 countries, the operations of building and loan 

 associations are very strictly controlled by spe- 

 cial laws. W.F.Z. 



BUILDING STONE. There are a number of 

 varieties of stone used in the construction of 

 piers and bridges, in the foundations and walls 

 of buildings and in the finishing of interiors. 

 These stones are known to the building trades 



HOW BUILDING STONE IS LAID 



(1) A rubble wall. 



(2) Field stone 



(3) Ashlar, in which all stones are squared. 



(4) Random-coursed ashlar. 



as building stones. Those most extensively 

 used in the United States and Canada are gran- 

 ite, limestone, marble and sandstone. In ad- 

 dition, onyx, marble and slate are used in 

 finishing interiors. Each of the stones named 

 above is described under its title. 



In selecting the stone for a building or other 

 structure, the architect or engineer is governed 

 by the following considerations: 



1. Strength required. 



2. Durability. 



3. Convenience of access. 



4. Expense of working. 



5. Architectural effect. 



Granite is the strongest and most durable 

 stone. It is usually selected for foundations 

 of heavy structures and for piers, and it is 

 frequently used for the walls of large buildings. 



Limestone in great variety is also used for 

 foundations, walls and trimmings. It is not 

 so strong as granite, but it is an excellent stone 

 for all ordinary foundations and walls. Marble 

 is softer than ordinary limestone, and is now 

 practically restricted in its use to stairways, 

 interior finishings and ornamental work. 



Sandstone of hard quality is used for ex- 

 pensive dwellings such as the "brownstone" 

 structures so famous in all large cities. It is 

 more brittle than limestone and will not with- 

 stand so great a pressure. Slate is used for 

 interior work in sinks, mantels and other fur- 

 nishings. It is very durable. 



Durability. The causes affecting the dura- 

 bility of building stone are the action of air 

 and rain (weathering), change in temperature 

 and chemical changes within the stone. Weath- 

 ering is the chief cause of change. If the stone 

 is porous it may absorb small quantities of 

 moisture from the air and from rain. When 

 the temperature falls below the freezing point 

 this water freezes and expands; the next sea- 

 son more water enters, effecting a further 

 change, until finally the surface begins to crum- 

 ble. The presence of iron or sulphur in the 

 stone is likewise a source of weakness. The 

 iron, on exposure to the air, discolors the stone, 

 and the sulphur is liable to unite with oxygen, 

 forming sulphuric acid, which attacks the struc- 

 ture of the rock. 



Building stone usually withstands the climate 

 better if used near the locality where quarried. 

 Many fine public buildings have rapidly lost 

 their beauty because constructed of stone 

 brought from a considerable distance. 



The following table shows the life of the 

 stones described, before they begin to show 

 deterioration : 



KIND OF STONE LIFE IN YEARS 



Coarse brownstone 5 to 10 



Fine brownstone 20 to 50 



Coarse fossiliferous limestone 20 to 40 



Marble, coarse dolomitic 40 to 50 



Marble, fine 50 to 100 



Granite 75 to 200 



Best Ohio limestone 100 to 200 



Nova Scotia sandstone 50 to 200 



The above variations in years are due not 

 only to quality but to location of the building 

 of which the stone is a part. 



