There are several ways serious drain problems may be repaired. Among these are so-called trenchless repairs that use an inner sleeve to seal cracks and correct misalignment in sewer and stormwater pipes.
Trenchless repairs can be done two ways: relining and patching. Relining is used predominately for long pipe runs that are inaccessible due to being located under driveways, expensive landscaping, roads, tennis courts or other obstructions that mean excavation is not possible. Usually pipes to be relined have significant, uninterrupted damage for a considerable length. In these instances, relining is a cost-effective option due to the added cost of replacement of landscaping, driveways or other surface features.
The other type of trenchless repair is pipe patching. Pipe patching is similar to relining, but is generally done in one metre lengths to correct isolated breakages or misalignments. In many instances, pipe patching is a more cost-effective option than excavation due to the depth or location of the pipe or type of ground to be excavated.
Pipe patching is relatively straightforward, but involves a number of steps:
- The pipe is first prepared for patching by cutting out all roots and clearing all debris with a jet blaster. A CCTV camera is then used to visually inspect the repair area.
- A woven fibreglass sleeve is impregnated with a polymer resin.
- An inflatable bladder called a “packer” is inserted into the sleeve and the sleeve is secured to the packer with elastic bands.
- The packer is inserted into the pipe and moved into position either by pushing with hollow rods used to deliver air to the packer or by pulling with a rope accessible through a downstream opening in the line.
- The CCTV camera is again used to ensure the patch is in the proper position.
- A compressor is attached to the rods and air is pumped into the packer until the sleeve is in full contact with the inner wall of the pipe.
- The sleeve is allowed to cure in place under pressure for approximately 1.5 hours.
- The packer is removed and the sleeve is inspected with the camera a final time.
Upon completion, the patch creates an impregnable inner liner as strong as PVC. It is particularly good for sealing joints in earthenware pipe where roots would otherwise continue to penetrate.
Pipe patching requires specialised equipment to assess the problem, prepare the pipe and complete the patching. Good Neighbour Plumbing has the tools and the talent to patch the crack.