The massive use of lightwave communication technology in the trunking and distribution parts of the networks brought the need for high efficiency optical fiber splicing methods. Among others arc fusion splicing is today largely used during installation and rearrangement of optical links. In this splicing method the mechanical strength around the splicing point is greatly reduce due to coating stripping. Our results with brazilian optical fiber aging tests show that the tensile strength average is 0. 55 GM/rn2 and the static fatigue of 0. 14 GN/m2is dangerous for the splicing part. Therefore the protection and the reinforcement of the splicing portion are intended to avoid optical and mechanical degradation. This paper examines the protection level given by heatshrinkable sleeves showing the results obtained from optical and mechanical measurements which are on multimode and singlemode fiber splices. The splicing characteristics were measured under normal conditions and after exposure to termal and wet adverse environments.