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 
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- 
