Tuesday, February 19th, 2013
Drainage engineers have to face a host of problems on a daily basis as part of their everyday jobs. And like all jobs some days things go according to plan and some days things become slightly more complicated.
The majority of drainage jobs a drainage engineer may visit will simply be caused by debris blocking the drainage pipe – a job which in most cases is quite easy to fix. However if this problem has happened a number of times, or if further investigation is needed the time it takes to resolve a drainage issue may increase.
If a customer has recurrent drainage problems it may be necessary to perform a CCTV survey. This will give the engineer a clear view of the inside of the drainage pipe so they will be able to assess what the problem is. Usually a small CCTV camera is inserted into the pipe and pushed along the pipe’s length recording deviations in the pipe, fissures, cracks or even pipe collapse. If the drainage pipe is large enough small remote controlled robots can be used, with cameras fitted, which can be rotated to view the pipe in clearer detail.
In a lots of cases that see frequent drainage problems it’s the pipe itself which has a problem. This might be a deviation in the pipe due to subsidence or it might be a crack in the pipe’s surface. Even small fissures around a join can provide an area for debris to accumulate and a blockage to occur.
If there is a problem with a drainage pipe it’s not always the case that the pipe will have to be excavated and a new pipe reinstated. In some situations it may be appropriate to instigate a pipe liner repair.
Methods used to repair a damage drainage pipe include:
Polyester liner resin repair
This method requires the drainage engineer to insert the polyester liner into the host pipe. The liner is then inflated so its surface adheres to the pipe’s walls. Because the liner is impregnated with resin, when the liner sets it bonds to the inside of the pipe walls and creates a watertight seal. Thus type of liner repair is more suited to straight sections of drainage pipe.
Epoxi Flexi liner
If the drainage pipe has deviated from its normal path this method of pipe repair will normally be used. An elasticated resin impregnated polypropylene sock is blown down the pipe on a carrier until it reaches the damaged area of pipe. The liner can traverse bends in the pipe and difficult to pass sections. Once in position the liner is allowed to set to the pipe walls and hardens creating a watertight seal.
While both these lining methods will reduce the pipe’s diameter slightly what is lost in the diameter is more than made up for by the increased drainage flow.
Pipe lining is an excellent way to repair a damaged pipe. And it works especially well in situations where it may not be viable to dig to resolve the problem. It can stop nasty smells emanating from cracked pipes and can stop water egress from the pipe’s structure.