Recently I decided to purchase a sewer camera and line locator. In all my years as a home inspector I have cautioned people on the risks of tree roots in the sewer line. After using the sewer camera I am learning that tree roots are only one possible issue with sewer related backups.
One of the most common problems I have come across since buying the camera is sagging lines. In this situation the line drops in the trench and then comes back up again creating a sort of trap for the solids to slow down and block the line. In severe cases I have witnessed a line that was plugged only one week after the local plumber had augured it out. Another common problem is offsets in the pipe. I personally have not experienced this issue as yet but I am told it is a common problem.
Other less frequent issues include a collapsed pipe or a broken pipe where a rock has pushed through the line . This week I came across a flapper valve which had been dislodged from a check valve. Last week I found an end cap from a piece of abs pipe which was partially blocking the pipe. So I guess the moral of this tale is that you can never be sure what may cause your sewer line to back up. The only way to be sure of the condition of the line is to have it scoped. At border Home inspections we have top of the line equipment to scope and locate the line issues if necessary. You will also receive a DVD copy of the scope at the end of the inspection.
If you are one of the many homeowners who experiences sewer back-ups on a recurring basis I recommend having the line scoped to see what and where the problems are. If the cause of the blockage is on the town or city portion of the line, you can provide the town/city with the DVD evidence of the problem and where they will need to dig it up. Without this type of visual evidence the repair process can be long and drawn out and resolution of who must pay is often in dispute. Visit my website to view a 6 minute video of this process in action.