Seattle Drain Service


Trenchless Pipe Descaling!

Dealing With Cast Iron Pipes Under Concrete Slabs

A very common problem for people in Seattle who own homes over 50 years old are cast iron drain lines (pipes) that run horizontally under the basement floor. The cast iron will rust and become very rough and debris will hang up in the pipe instead of flowing away to the sewer system. This can be 4" sewer lines to 2" laundry and floor drains. A snake or even a hydrojetter will not remove the build up or scale. In modern times a plumber may run a camera down the line because of repeated backups. Be prepared when you see the inside of the line it will look terrible! Like the bottom of a ship that has been at sea for 50 years. If the problem has gone on for a long time the pipe can even rust the bottom out. Usually when shown the camera footage of the pipes clogged condition the homeowner is told that the floor must be broken up and the pipe replaced. And in the past this was in fact the solution. But times have changed and now another method called cast iron pipe descaling is available. The huge costs to break up the concrete floor on an unfinished basement where high enough but skyrocket if the basement is finished and expensive flooring must also be removed and then installed again. Descaling will not fix a pipe that has no bottom in it. But most of the time that is not the case it just looks like the pipe needs to be replaced. Our method usually means going outside where the pipe exits the home and connects to the sewer in the yard the transistion between inside cast pipe and out side clay or concrete or plastic sewer pipe. Then working backwards or upstream we grind out the cast iron pipe while flushing it to remove the rust dust build up. Then when the camera is sent in the pipe looks brand new! This does 2 important things the pipe is now full size diameter again and smooth so things will slide down the pipe. Other options are to coat or spray the inside of the pipe with a teflon coating to prevent rust and make it even slipperier. This example was based on a 4" pipe. If you have a 2" pipe that goes to a floor drain most of the time because it has a trap you must break up a 1 foot area around the drain to descale the line then replace the drain with a more modern plastic one. And even if a bad worn through spot or two is found pipe patches and even lining may be used to restore or repair the pipe. The cost is usually less then open trench methods and the disruption to life is not even comparable.

So call us at 206-471-3008 or email to set an appointment.

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