An informed decision rather than an educated guess.

I am regularly called in to clear a blocked drain that has been cleared by other plumbing firms, on a regular basis. I will generally recommend the use of a drain camera /pipe camera in combination with the hydro-jetter because  it is a significantly more efficient method of clearing a blocked sewer. A drain camera will operate submerged in water during the cleaning process. The hydro-jet cuts through obstructions, (generally tree roots), at approximately 35,000 kpa with minimal water usage & without damaging the drain, unlike mechanical methods such as “Electric eels”, which hack at the obstruction, which is the most common method used by other plumbing firms.
Click on TV Longbeach for vision of the hydro-jetting . http://www.youtube.com/watch?v=GwhLPEfJkCM
The majority of the time, a pipe camera will reveal multiple tree root incursions that an electric eel has only trimmed to encourage renewed growth. The pipe camera enables the hydro-jet operator to place the jet head on each tree root incursion, so it can be completely cut to the inside diameter the drain. This leaves the sewer system free of obstructions so any structural faults are visible.
Pipe camera inspection is conducted with the aid of a colour, self-levelling push rod camera and the information recorded to a DVD on site. The vision can be reviewed at a later date for further interpretation and analysis.  There is a sonde located in the camera head that identifies the position & depth of the camera to map the position of the blockage, obstruction, structural failure or to simply map the drainage system itself.
With the CCTV drain inspection completed my client then as the ability to make an informed decision on the method preventing ongoing sewer blockages. There are many solutions available, ranging from replacement of the sewer, relining the sewer, regular clearing of the drain or treating the sewer with Sanafoam Vaporooter. (Click on TV Longbeach. For vision of vaporooter treatment of a sewer main in Toorak http://www.youtube.com/watch?v=lXULc5BzE-8 )Longbeach plumbing has work in Parkdale, Cheltenham, Mentone, Sandringham, Hampton, Brighton, Beaumaris, Highett & Moorabbin in the last week.