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Sewer line replacement options?

Posted by politicaux (My Page) on
Mon, Mar 23, 09 at 19:59

I've gotten some great info over in the HVAC forum, so now it's time to confront my sewer demons.

I'm currently under contract to buy a gutted (down to the studs) home in New Orleans, with the intention of rebuilding it and moving in over the next few months. I had the sewer line scoped last week and found major issues, now trying to identify my options to determine whether I can close the sale.

The house is one story, monolithic slab foundation. Generally, there is a kitchen on the right exterior wall and two bathrooms on the left exterior wall. The existing sewer line runs from the kitchen across the width of the house to a main line, which runs from the back bath straight forward to the street. We've found 2 breaks on the main line: one above the junction with the kitchen line and one below. The kitchen line is also obstructed about 15 feet from the drain by debris from demolition after Katrina. That leaves about 1/2 of the line that we can't get to with a scope (between the two breaks and the obstruction).

I've gotten three suggestions:

1) Tunnel underneath the house along both lines replacing all sewer lines with PVC. This would require one tunnel that would almost completely cut the house in half from front to back, then a second to come up the center of the house and replace the main line.

2) Run new lines up each side of the house to provide sewer access to kitchen and both baths... requires demo and replacement of driveway and tunneling to existing drain locations to tie in. I've been told (without explanation) that this solution (which was mine) isn't feasible.

3) Cut channels through slab w/ concrete saw to lay new sewer line from front of house (where current line is intact) to baths and kitcen (essentially carving a V into the slab).

Needless to say, the thought of cutting the slab into three sections and then patching it makes me EXTREMELY nervous, but two contractors have told me it's nothing to worry about.

Can anybody with any experience in this offer thoughts or suggestions? I can provide add'l details if necessary.

Follow-Up Postings:

RE: Sewer line replacement options?

How about raising the house?

RE: Sewer line replacement options?

Raising the house costs $30,000 and upwards... it's going on every day by those who got FEMA grants, but unfortunately it doesn't look like we'd be able to. That amount breaks our budget, and we'd still have to fix the sewer lines (although they would be easier to access). If you were thinking of the ICC elevation grant, we're still chasing that tail but it looks like we're not eligible (the seller/owner during Katrina didn't file anything to claim any of her allowances).

RE: Sewer line replacement options?

Happened to trip over this convention announcement. The 2008 section has big lists of websites that might have the experienced contractors or contacts you can reach.

Here is a link that might be useful: No dig technology

RE: Sewer line replacement options?

There are such things as no-digs but I guess it depends on the condition of the pipes - if they are too far gone or not, but there is a sleeving/relining technique that allows the pipes to be repaired in place, with only a small access point. Expensive I'm sure but designed to be competitive with a full dig and relay.

RE: Sewer line replacement options?

I looked into the trenchless options, they don't really work for our scenario. First, the existing line might not be in good enough condition to support trenchless replacement. Also, while we can dig a whole at the city side, the lines terminate under the slab so there's no way easy way to create an entry point for the new line. There's also several joints under the slab, and we'd have to tear out the driveway to get to the existing line on one side.

So far, our estimates are $12k (to tunnel to the two known breaks and replace only those portions) or $20k (to tunnel the entire width of the house and replace the entire system).

A SEPARATE OPTION: I'm admittedly no expert, but I see a way to run two new lines - one up each exterior wall) which would serve the entire house with minor tunneling. The disadvantage is that the sewer line wouldn't be under the house, it would be buried under the strip of grass on either side. One company says they wouldn't do it that way because the line isn't protected by the house and could break more easily. To that, I say that if it breaks, it would be a MUCH easier fix than if a line were to break under the slab again.

Is there any reason a new line can't be run outside the exterior walls of the house?

RE: Sewer line replacement options?

I had a small business that hooked to city sewer. The original line came out of the back of the building. A trench was dug from the back, along the side, thru the front yard to the street. About 150'.

Our previous house had the sewer line come out the side of the house and then to the street. Lots easier to repair and/or replace.

If you bury it deep enough it won't be a problem.

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