How trenchless sewer repair works:
Pipe bursting is a simple way to do a trenchless sewer repair. First, you do a sewer scope. Locate the cast iron pipe outside of the house, where the cast iron meets the concrete pipe, this is the start point for your repair. Then, locate the pipe at the city curb, this is the stop point of your sewer repair.
Next, if there are no bellies in the sewer line, you dig around the cast iron pipe next to the house. That’s usually where the rain drains tie into the sewer line. This is a weak point and rats will use this access point to get in and out of the sewer system. Next, dig at the city curb. NOTE: In Portland, Oregon the home owner is responsible for the sewer line to the city curb even though most of the cities around Portland make the home owners responsible to the sewer main — the difference in cost for trenchless repairs in Portland compared to nearby locations can vary greatly.
Then a 3/4 inch cable is put down the sewer pipe. It hooks to the burst machine and the burst head. In turn, this will be hooked to the new pipe that is made of high-density polyethylene or HDPE pipe. HDPE pipe is strong and will bend around 45% and 90% turns. It will last the lifetime of the house.
The pipe bursting head is made of steel and weighs about 20 pounds. It has a fin that helps cut the old the pipe and fittings, and it hooks to the HDPE pipe by compression. It actually takes more time to set up than pull in the pipe. In fact, the set up can be a real challenge with old sewer lines — you just don’t know what might be down there — I once opened a hole in a city curb and found a cave around the sewer line and water meter on top of that. The job was a challenge with the water line just on top of the sewer line. The good news is that once the set up is done, pulling in the pipe is the easy part.
Even after all these years, when it comes to trenchless sewer repair, I just plan on the unexpected.
NOTE: Bellies in the old sewer lines can be overcome by digging right at the spot and pulling through it after the old pipe has been pulled out of the way. So if the sewer inspector has said it can’t be pipe burst, think again, even if you have to have three holes, it’s better than the whole yard or your drive way, dug up. That’s the way we do it.