Spot repair using mats impregnated with resin is applied in non-passage sewers with local damage to walls or joints. The works are performed in stages. This technology allows to carry out works in both summer and winter conditions. The short-sleeve technology is designed to repair small, non-repeated failures (joint leaks, spot defects in the structure, local cracks) due to the ease and speed of assembly. The processes described below should be performed by qualified employees since despite the simplicity of the system, the time and precision of particular activities as well as OSH training are of great importance.

When assembling the sleeve, we can distinguish
the following stages:

  1. Preparation of the mat
    Preparation of the mat consists of cutting the segment of the desired size from the sheet. The length is determined depending on the length of the channel damage with a supply of 15cm on each side. The width of the mat depends on the diameter of the wire and should suffice to wrap the „packer” 2 – 4 times.
  2. Resin preparation
    The resin is a two-component product combined at the site of work. Semi-finished resin products are available in 10L and 30L canisters. The components are mixed until a homogeneous form is obtained in a volume ratio of: 2 parts of base component + 1 part of hardener. It should be remembered that next steps have to be finished in 30 minutes until the resin loses its liquid consistency.
  3. Soaking the sleeve with resin
    Applying the resin on a fiberglass mat is made with a steel trowel. It is essential when performing this operation to evenly distribute the resin on the entire surface of the sleeve.
  4. Applying the mat on the packer
    Soaked mat should be wound on the „packer” in 2 to 4 layers, taking care that there is no puckering.
  5. Inserting of the mat
    Prepared „packer” is drawn into the repaired channel and set in the place of damage. A camera is useful in this stage, thanks to which the sleeve can be positioned exactly.
  6. Resin hardening
    Introduction of compressed air to the „packer” causes the sleeve to fit into the channel walls and squeeze the resin in place of losses (cracks, leaking joints). When using heated air, the hardening time of the resin is shortened.
  7. Removal of the packer
    After the resin setting time specified by the manufacturer, the „packer” can be removed from the canal.