Coastal Climatic conditions have a significant impact on the life expectancy of treated wood in Southwest Florida. Our humid climate is more favorable to decay in wood utilized outdoors than northern dry or cold climates.
A prospective condition for decay exists when treated wood is sequentially wet and dry, or in interaction with the ground where it can absorb moisture and remain damp for an extended period. The rate at which piling deterioration takes place depends upon the nature of fungus, the treatment characteristics of the wood post and the measure of exposure to moisture and warmth. Florida’s constantly changing weather patterns, especially during our afternoon thunderstorms, wreak havoc on exposed wood timbers. Timber piling decay may gradually progress as to be scarcely noticed, eventually destroying the integrity of a wood piling.
Moisture, Air, and Warmth
Timber decay is not limited to the ground line area but is repeatedly discovered also in the tops or sides of pilings many feet above the ground.
To survive, all decay fungi require four things, moisture, air, favorable temperatures, and suitable food material. If the other conditions are precise, they get their nourishment from the wood.
All life requires air, food, water, and an adequately warm natural environment or habitat to survive. Instinctively, the fungi, mold, insects, that inhabit and consume wood piles are no different.
Submerged or deeply penetrated wood piles, such as submerged piling that supports the foundations of stilt homes or large structures such as bridges, contains too little to no air. The soil becomes oxygen deficient a few feet below the surface of the ground because air supply is non-existent. Research determines at depths of more than five or six feet, the degree of decay is usually very slow.
If you discover a pile which is compromised, it is critical to have the timber piles and the building substructure inspected by structural engineering consultants and a foundation contractor experienced in wood pile deterioration and remediation. It is paramount that the homeowner must engage experts to assess the life safety risk concerns caused by the deteriorated building foundations and destabilized piles.
All timber piles subject to decomposition will eventually deteriorate and become too compromised to safely support the structure above. In an emergency, the elevated structure may be strengthened by placement of straps or steel sleeves to bond the solid portions of the pile together. Alternative approaches such as, installation of helical piling or screw piles to support the building above the ground, can be introduced. Ultimately, the timber foundation system longevity and engineered service life must be renovated, and a new engineered foundation system installed.