(a) Field of the Invention
The present invention relates to a threshold assembly for blocking water, and particularly to a structure which does not require wet cement and is suitable for dry installation. 
(b) Description of the Prior Art
Conventional thresholds for blocking water can be made of man-made marble, stainless steel or constructed of concrete and cement.  However, the construction work of the above-mentioned conventional thresholds has to be executed during the course of laying the door frames.  This means that the installation work involves first mixing the concrete and piling the bricks, and thereafter the prefabricated marble or stainless steel threshold is attached to the wet cement.  This is the so-called wet-typed cement construction of the threshold.  The threshold cannot be installed after the door frames and painting are completed.  For this type of installation, it takes longer to build the threshold because of the heavy cement work involved.  In addition, the cement work could be damaged by external vibration before it dries out, thereby causing a gap (for leakage) in the threshold construction.  Nonetheless, the physical sizes of the marble, stainless steel and bricks are bulky, making it hard for transportation.