The work aims to determine the conditions necessary for the sliding of the sand layer on slightly inclined surfaces of granular ice of the porosity about 0.5. We studied a layer of fine or very fine silicate sand. It has been found that a layer of very fine sand can begin to slide on the surface of the porous granular ice at an angle of inclination as small as ten degrees. Our measurements also show that sublimation of vapor from uncovered porous ice may be slower than from compact ice.