<p class="MsoNormal" style="margin: 0cm 0cm 10pt;"><span style="font-family: Times New Roman; font-size: small;">Although the spreading of salt onto snow on Shabbos is permitted, the spreading of sand is more problematic. Some authorities forbid it saying that one is adding a new permanent layer to the ground and it would thus be forbidden under the prohibition of boneh. Others however hold that it is permitted since this layer cannot be considered as permanent. [see Rabbi Dovid Ribiat, &ldquo;The 39 Melochos&rdquo;, volume 2, pages 368-69]</span></p>