The present injection apparatus is designed for replenishing embedded foundation preservation wraps with preservative whilst avoiding spillage. The injection apparatus comprises an injection bayonet having a lumen fluidly interfacing a plurality of preservative outlet nozzles along the injection bayonet and a preservative inlet fluidly interfacing the lumen. A portable preservative containing tank may be attached to the inlet via a flexible hose. The apparatus further comprises a syringe operating between the preservative inlet and the lumen. When replenishing the preservation wrap, the injection bayonet is inserted between the preservation wrap and the foundation so that preservative is configured to be supplied via the preservative inlet to flow out from the nozzles via the lumen to replenish the preservation wrap with the preservative. After replenishment, the lumen is purged of residual preservative using the syringe.

A system for replenishing embedded foundation preservation wraps with preservative comprises an embedded foundation, a preservation wrap, and injection apparatus configured to be inserted between the wrap and the foundation. The injection apparatus includes a profiled backing plate and a semicylindrical tube portion defining a lumen therebetween, with a preservative inlet and a plurality of outlet nozzles along a distal bayonet fronting portion. A syringe with a reciprocating plunger operates within the lumen to enable controlled delivery of preservative and purging of residual preservative after use. The plunger may be locked in retracted, inserted, or blocking positions to manage flow and prevent leakage.

A wood structure such as a post (36) is preserved by providing a reservoir (9) filled with oil (34) and allowing the oil to dran from the reservoir (9) under gravity through a spout (16) to penetrate the post (36) from inside and saturate the wood of the post (9) with the oil (34).