Highbury Stone does all types of repair work with both natural and pre-cast stone. An example of both flagstone and interlock repair is given below.
Problem: The most common type of repair with interlock projects is known as a "lift and relay." This repair is required when the initial installation of the interlock stone has been installed onto an insufficient base therefore causing the stone to sink in places.
Solution: The method of repair is to lift the area of sunken interlock, add more base material and then compact the area. A thin levelling layer of screening or sand is then added. At this point, the interlock stone is ready to be reinstalled. Once reinstalled the area is compacted to level and polymeric sand is swept into the stone joints to prevent weeds and insects. The area is lightly hosed to harden the sand.
Problem: The most common type of flagstone repair is needed when the stonework joints have eroded and then moisture can penetrate through and underneath the stonework causing it to lift once it freezes during the winter cycle.
Solution: The solution is to grind out the jointwork and lift any loose stone. The base beneath the stone is removed and the stone is then re-layed on a new mortar bed. New jointwork is installed to complete the job.
Prevention: Salt can be very erosive towards jointwork. One way to prevent this occuring again is to avoid putting salt products on the flagstone during the winter months. Ask at your local hardware store for recommendations on stone friendly products.