Gregg Henderson, Dunaway, Christopher R. | 4/18/2005 8:27:15 PM
Brick and Mortar Piers
Brick and mortar piers, common in most of the old homes in New Orleans, are some of the most difficult to inspect and treat. The problem is that Formosan subterranean termites can travel through the center of the pier as easily as they can travel up the exterior. Furthermore, it is difficult to apply a continuous chemical barrier that the termites cannot bypass. (See figure 1.)
Proper treatment requires that the soil around each pier be treated by trenching or drilling. Each pier must then be drilled between every other brick to reach the center and chemical applied to the holes.
Look at all four sides. Carefully examine the sills, floor joists and sub-floor in the area around each pier for signs of infestation like shelter tubes or damaged wood. A screwdriver or similar tool us useful for probing the wood.
Hollow Block Piers
With this type of pier, subterranean termites can enter the structure by tunneling up the outside of the pier (as seen in figure 2) or they can travel through the center. Proper inspection requires that each pier be examined on all four sides and that the wood above each pier be examined for signs of damage and infestation.
Treatment requires adding a chemical barrier around all four sides of each pier by trenching or drilling. The interior of the blocks should also be treated by drilling each void or pouring the product in from the top when possible.
Inspection: Similar to that of brick and mortar.
Both brick and hollow block piers can be greatly improved with the addition of solid concrete bases or caps.