HEAVY TIMBER 



tions are used, the footings should be made 3 feet thick with 

 the pile head extending 1 foot into the concrete. Foundation 

 piles should not be spaced closer than 2 feet on centers in any 

 direction, and at least 2 feet 6 inches should be allowed in one 

 direction. Wood piling should always be cut off below water 

 level unless creosoted. Thorough creosoting is recommended 

 for all exposed piling. 



Wherever exposed to the action of frost, footings should 

 lie from 4 feet to 6 feet below grade, depending upon the 

 climatic location. In any case footings should be carried to 

 the firmest bearing strata within reasonable reach. 



The thickness of the foundation walls or the size of the 

 isolated piers will depend upon the load to be carried. This 

 load is determined approximately from preliminary plans of 

 the building, and from the weight of machinery, equipment, 

 or materials which is to be carried on the floors of the struc- 

 ture. In calculating the live load, allowance must be made 

 for the effect of impact from machines and equipment together 

 with the overturning effect on the leeward side due to the wind. 



If the soil is wet and a dry interior is to be assured, the 

 basement walls and floor should be waterproofed during con- 

 struction. This waterproofing may consist of a continuous 

 layer of bituminous material placed on the outer surface of 

 the walls, extending through the walls at the footings, and 

 forming a tight membrane under the wearing coat of the base- 

 ment floor, or by the use of a rich, properly graded mixture 

 of Portland cement concrete containing a reliable integral 

 waterproofing compound. 



Exterior City building ordinances as well as the recommenda- 

 Walls tions of insurance underwriters generally specify 

 exterior walls of an incombustible material such as 

 brick, stone or concrete. The pilastered form of brick or re- 

 inforced concrete wall gives large window areas and furnishes 

 support to the main girders of the floors where needed, but 

 may lack the rigidity of a solid wall. This general type of con- 

 struction may be carried out either in the form of curtain walls 

 or panel walls at the choice of the designer. In the absence of 

 a local building ordinance which determines the proper thick- 

 nesses to be used in the different parts of brick or concrete 

 exterior walls, it is suggested that the sizes given in the 

 Building Code Recommended by the National Board of Fire 

 Underwriters be followed. 



Page twelve 



