One of the many things on my Spring to do list is to check over my walkways and stone walls. The winter can wreak havoc on these normally solid structures. Whether your walkways are stone or pavers the water from thawing snow and ice may have worked its way through the cracks. What commonly happens is water will seep in between the stones and freeze. As the water freezes it expands and applies outward pressure on the surrounding material. If the walkway was installed over good drainage material, usually gravel and sand, the water keeps seeping lower and no harm is done. Unfortunately in many instances the water freezes closer to the surface. This can have a few different results.
In some cases the expansion will create void by pushing materials out of the way. This causes the stone or paver to sink and create a low spot in you walkway. These same forces can also push upward. This causes the stones to heave up and create uneven surfaces in the walk. Both of these situations can lead to trip hazard and overall deterioration. When it comes to repairing these issues, it really depends on the type of walkway that you have. Pavers will need to be leveled. This usually involves lifting the pieces in questions and either adding or removing material. The use of stone dust or sand is a common way to make these repairs. There are some walkways sands that are available that are combined with polymer beads that will expand with water. These help to lock stones in place. Repairs of concrete and stone walks tend to be more complicated. Many times it involves breaking joints to free stones and reapply material to level and secure the stones. These types of repairs are usually left to qualified contractors. Be sure to use a contractor that has experience and the qualification to do the work.
Other issues that I commonly see are walkways with deteriorated mortar in the seams between the stones. Mortar is a term that we commonly use but stone walkways are usually set in a concrete of some form, but that is another article. It is very common to use rock salt to thaw the ice in the wintertime. Common rock salt is made of sodium chloride. It works great at melting the ice; unfortunately it is also very corrosive to concrete. It is important to use a salt that will melt the ice and not damage the binding materials in the walkway. Be sure to read the information on the melting salts that you use next winter.