The results of studies of thermochemical modification of the surface of a glass ribbon in continuous production are presented. It is shown that the deposition of a composite coating, which was developed by the present authors, on the surface of the glass increases its water resistance by an order of magnitude and the mechanical strength about 2-fold. The essence of the proposed development lies in the deposition in several stages of chemical reagents which create on the surface of the glass a transparent film that permits controlling the quality of the float-ribbon.Key words: float-ribbon, thermochemical modification of a glass surface, water-resistance of glass, mechanical strength of glass.Sheet glass has a substantial place among the various materials now used in technical structures and buildings.Owing to its unique property -transparency together with strength and hardness, in a number of cases it cannot be replaced by any other material. The percentage of glass can exceed 80% in modern buildings.In order to guarantee the safety of the glazing of tall buildings and the durability of glass articles in service the mechanical strength of glass, as the main service characteristic of glass, must be increased [1].It is known that the mechanical strength of float-glass is a statistical quantity and is characterized by a large variance of its values (from 20 to 200 MPa). For this reason, the most likely statistical value of the strength or of the minimum values of the strength should be taken as the guaranteed operating characteristics. Such indicators can be introduced into the standards for construction glass.Approximately 40% of construction glass is lost during storage, transportation, and mounting. This is because initially the float-glass is too weak and its strength decreases because of corrosion. Stacked sheets of glass are exposed to the humid atmospheric air and temperature differentials, which can result in the appearance of defects such as surface leaching. For this reason, the water resistance of construction glass is also its service characteristic, and the problem of increasing the water resistance is urgent.The operating properties of sheet glass (strength and water-resistance) are determined mainly by state of its surface.It is well known that because of the particulars of its technology the properties of float glass show a substantial variance along the width of and between the surfaces of the ribbon. This is especially true for the mechanical strength of glass (Table 1).