344 



Philippine Journal of Science 



191* 





Fig. 4. 



Detail of termite-proof construction ; a layer of cement 

 at ground level laid in three parts. 



parts, and each part is spread over the ground at a different 

 time. After all the parts are joined together, the whole surface 

 is covered with cement mortar. At a glance such a concrete 

 layer seems as satisfactory as the ordinary layers. However, 

 junctions between the sections are not tight enough to prevent 

 the intrusion of the termites, and in many cases it was proved 

 that the concrete layer had been penetrated by Coptotermes 

 formosanus when it was ill-constructed; that is, with the layer 

 divided into several parts. 



Sometimes the architect is required to build the ground floor 

 somewhat higher than the ground level. In such cases the 

 concrete layer should be constructed as shown in fig. 5, and the 

 two layers on different levels connected by another vertical 



n 





T ^ VH-rrt^ 



Fig. 5. Detail of termite-proof construction : the protec- 

 tive layer at two levels. 



layer. This method is not advisable, however, because of the 

 presence of many junctions, which are liable to be passed through 

 by the termite. If it is necessary to raise one part of the floor, 

 it is better to make two concrete layers separately, instead of 

 joining the two. 



First floor. — Dark places with a proper quantity of moisture 

 are most favorable for the habitation of Coptotermes formo- 



