The best way to sand a deck is by cleaning it, sanding the boards and stairs with 60- or 80-grit sandpaper, and sanding the railings and posts with 80-grit sandpaper. You should sand in the direction of the wood grain to avoid damaging the timber. When sanding your deck, use medium pressure and aim for an even sand. Pressing too hard with a sander can damage decks, as most are softwoods.

The cost of sandblasting depends on the scope of the project, the surface type, labor, and equipment required. Services typically cost between $50 and $80 per hour, though most professionals charge by surface area at a rate of $1.50 to $7 per square foot. Total project costs can range from $700 to $12,500, with an average homeowner spending around $3,200 to sandblast a 1,000-square-foot surface.

Sand is a common sublayer for hardscape features like driveways, paver patios, and more. Most projects that involve sand require a 1-inch layer to promote evenness, drainage, and weight distribution. For further drainage, most projects have a 6-inch minimum layer of gravel beneath the sand. 

Because these two systems have different applications, there is no definitive answer to which is better. When working with sturdy materials, sandblasting is cheaper and faster, but more delicate projects require soda blasting. Before choosing either option, consider your specific needs, particularly your ultimate goal (cleaning, removing rust, prepping for painting, etc.), the material, and your budget.