Draining Pipe In Old 3Ng Flat

[hatisinga 0]

When I moved into my current flat 34 years ago (that's right: its thirty four years!) the draining pipe from the kitchen sink runs along the wall of the kitchen for about three meters before it enters into the floor trap. The draining pipe is a steel pipe and is covered by white wall tiles measuring 4 inches X 4 inches. The pipe choked frequently as waste water must negotiate several turns before emptying into the floor trap.

About 10 years ago (and after many pipe chokes), we got a contractor to embed another drainage pipe from the kitchen sink to the floor trap under the floor. We never experience chokes anymore as the newer pipe is shorter and it utilises a direct route from the sink to the floor trap. We stop using the original draining pipe altogether from this time.

The second pipe started leaking a few days earlier. HDB says that we should never have embedded a pipe under the floor in the first place. We would now have to abandon the use of the second pipe. We were offered various proposals after talking to various contractors:

1. Lay a new draining pipe on top of the original draining pipe. This is the simplest solution and costs only $60. I am personally not in favour because a pipe on top of another (covered) drainage pipe does not look aesthetically pleasing.

2. Another contractor suggests re-using the original pipe (which has been in hiatus for 10 years). He offered to clear the chokes and re-install some sections of the original pipe which were cut off by previous contractors. This costs $380 and will take 1.5 days to complete.

3. Yet another contractor said that I should simply replace the original pipe with a new pipe. He does not think that it is possible to re-use the original pipe, and even if somehow it is possible to get the original steel pipe to function again, there may be problem with the joints which will weaken the pipe in the next 2 to 3 years. Replacing new pipes however would cost $400 to $500.

So, what do you think I should do? I am not in favour of the first proposal. Personally I find the second proposal attractive but I am rather skeptical that a steel pipe nearly 35 years old will still give good service for the next 10 years. Please tell me what is workable and what a fair price would be.

Many thanks in advance!