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steveo333 11-08-2010 10:18 AM

What would cause back graded water pipes on a 3 year old house.
I bought my house which was new in december 2006. This past weekend my downstairs toilet started to overflow while i was taking a shower. I called a plumber service out and they did there checks with a camera and unclogged the pipe. They told me that the pipes were back graded which is fine. What would cause 3 year old pipes to be back graded. Surely that shouldn't happen on new houses. After the plumber left we are still having a blockage problem. He said the water pipes run under the concrete slab which would have to be dug up in order to fix the problem and said to fix it and replace carpet and walls it would cost around $10,000. Did he do a thorough job. Why would they put pipes under concrete through the middle of the house. Of course my new beazer home only came with a 2 year warranty which now come to think of it is ridiculous. My vacuum cleaner has a longer one.
Any advice would be greatly appreciated.

md2lgyk 11-08-2010 10:56 AM

What do you mean by "back graded?" Not familiar with that term.

Daniel Holzman 11-08-2010 11:43 AM

I am having a hard time following your post. I too am unfamiliar with the term "back graded", do you mean the pipe runs uphill? You state that the plumber unclogged the pipes, but in the next sentence you state that "after the plumber left we are still having a blockage problem". Did the plumber unclog the pipes, or leave without unclogging the pipes?

In the next sentence you note that the plumber indicated that the water pipes run under the slab, and would have to be dug up to "fix the problem". Is this a different problem than the clogged drains? I assume so.

I do not understand why, based on your post, the plumber believes there is a problem with the water lines. Is there a leak? Lack of pressure?

Perhaps if you fully describe the problems you are facing, and the steps you have taken to resolve them, we can understand your situation better, and offer some suggestions.

steveo333 11-08-2010 11:59 AM

What would cause back graded water pipes on a 3 year old house.

Sorry i'm just using the words the plumber gave me. From what he said the pipe doesn't run down hill allowing the water to run freely.
When the plumber left all drains were draining properly. 12 hours later we started having the downstairs toilet block again which was unclogged by a plunger but still continued to happen every few hours.
Under our house is a concrete slab and he said our water pipes would be running under it so to fix the pipe in a uphill position it would need to be dug up to get to it.
Thanks for your reply.
I appreciate your help.

AllanJ 11-08-2010 03:36 PM

You might want to get a plumber with a video snake to see if indeed there are portions of upslope or places with dips (called bellies).

Viewing the inside of the line and gradually pushing the snake through and also running water through, the plumber can see where water drains properly and where it doesn't.

Daniel Holzman 11-08-2010 08:42 PM

I still am confused. Are you using the term "water pipe" to refer to the drain, or are there two separate issues, one for the drain and the other for the water pipe? The term water pipe usually refers to potable water, NOT drain lines. I am guessing you mean that the drain runs under the slab, which is a bad plan because it is hard to repair if it breaks, as you have discovered.

Anyway, please confirm that the problem is that the plumber believes your drain line does not run downhill, and is located under the slab where it is inaccessible.

If this is in fact the case, you have a few choices. One of course is to dig up the pipe by breaking the slab, then relaying the pipe so it has proper pitch. Drain lines must always run downhill, I think the usual minimum slope is 2 percent, but this may vary with jurisdictions. An alternative would be to install a new drain line that is NOT under the slab, if you have the room on your lot.

You don't mention if you are on city sewer or a septic system, this is going to make a huge difference in how you approach the problem.

TheEplumber 11-08-2010 09:19 PM

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Back graded means the pipe graded the wrong direction. The waste water is trying to run uphill. Us plumbers say, "hey you dumb__ apprentice, your pipe is backgraded! Grade it the right direction":laughing:
Water lines will have nothing to do with your drain lines- you must have your words confused.
Another thought, If your backing up after 12 hrs. you may want to consider having your main line jetted. You may have a "soft blockage" or a lot of sludge. Cableling will open these but only slightly. They are pron to stop up again. Using high pressure water flushes them out. With all the sludge removed, you get a better view of the defective piping too.

Wildie 11-08-2010 09:32 PM

My house has full basement and the soil pipe (4" cast iron) runs under the concrete floor before exiting the building, and going to the municipal sewer.
When you mention the slab, would this be a basement floor or is the slab in a crawl space under the house. Or perhaps its a patio slab that you are referring to.
If your soil pipe does't have 'fall' solids will not be moved away from the building and will very quickly become blocked.
Part of the municipal plumbing permit inspection should have established that proper slope exists before the excavation is filled in.
If the inspector failed to check this, then the money that was paid for the permit, was wasted.
I would approach the municipal inspection department and make inquiries, as to why this condition exists.

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