pam220 - We do have Bar Grating that will carry the load of heavy, wet snow. Yes, snow would pass through, but it may also pile up if it snow hard enough quickly enough. It make take some time for it to melt through. We have a GW series of Grating that handle moderate loads like light wheel traffic, and a SGW series, which will handle even heavier loads. There is no maintenance required if you purchase the correct material (Galvanized Steel Aluminum, Stainless Steel, etc). You can talk to one of our sales representatives at 800.237.3820 or chat with them live oat www.mcnichols.com.