There are a few different types of sealers that can be used to protect concrete from the hard effects of winter, but if you are looking for the best winter sealer, consider a high solids silane siloxane sealer.

De-Icing salts and warmer days will melt the snow and ice. The concrete, much like a sponge, will absorb the water where it will re-freeze within the pores of the concrete. Ice takes up more space than water so when the water turns to ice, it expands causing the concrete to chip and spall on the surface.

A silane-siloxane sealer will cause water and other liquids to bead off the surface, preventing the water from penetrating into the concrete. When water freezes, it will freeze on the surface, as apposed to in the surface.

When choosing a silane siloxane, go with a high solids solution, solvent based, and preferably DOT approved. This certification proves the product has gone through very rigorous ASTM testing.

Best Sealers:

• Armor SX5000 (40% Solids, Solvent, DOT Approved)
• Prosoco PD (7% Solids, Water Based, no certification)
• OKON (20% Solids, Solvent, no certification)

Silicates

Some manufactures like to push silicates for sealing exterior concrete. Silicates should only be used to increase the strength of the concrete. Silicates do not cause water to bead off the surface so when ice melts, the concrete will absorb the water.  If you truly want protection from winter, you need to seal with a silane-siloxane. If you want to increase the strength of your concrete as well, you an put down a silicate then apply a silane siloxane to the surface a week later.