Re: Small Sewer Pipe Problem

[regrow]

Hi All

I have just found out that there is a sewerage pipe that runs across my block of land.

It is 1mtr in from the rear and is approx 2.2mtrs deep and runs across the width of the block.The area of the building affecting this is 8 Linear mtrs which runs in line with the pipe. See attached (Basic) drawing.

Our house plan is setback 1.5mtrs from the rear and left hand side fences.

I have been quoted approx $5k to have piles placed under the slab to hold the house up. Does this seem reasonable? (House is yet to be built and is in WA)

The following is from the Water Corporation received in an email.

There is a 150VC sewer main approx. 2.20m deep running on a 1.0m alignment inside the rear northern boundary.
Building to have minimum setbacks from sewer main of 2.50m to be clear. Or no closer than 0.60m with piles under foundations to below sewer main invert level (approx. 0.60m AHD)

Should the conveyancing firm not been able to find that the pipe was there?
I am waiting for them to retrieve my file from their archives and get back to me.

Also what happens in years to come that the pipe needs to be replaced? Do they just come in and dig up the exposed concrete that we will have layed over it and the backyard? Do they replace the concrete and grass?

Any thoughts or expertise in this field?

Regards

 

[jim1964]

I cant comment on your question here,but i can comment dealing with sewer lines with government departments is a mine field.I am in S.A. and have a sewer querie,8 different phone numbers,3 different departments and 3 hours on the phone,with not one answer.I did get a email response from SA Water...........Unfortunately we have no internal drainage plans for your property. Sorry for any inconvenience caused.

 

[Jake D]

Hi All

I have just found out that there is a sewerage pipe that runs across my block of land.

It is 1mtr in from the rear and is approx 2.2mtrs deep and runs across the width of the block.The area of the building affecting this is 8 Linear mtrs which runs in line with the pipe. See attached (Basic) drawing.

Our house plan is setback 1.5mtrs from the rear and left hand side fences.

I have been quoted approx $5k to have piles placed under the slab to hold the house up. Does this seem reasonable? (House is yet to be built and is in WA)

Yes, this seems reasonable

The following is from the Water Corporation received in an email.

There is a 150VC sewer main approx. 2.20m deep running on a 1.0m alignment inside the rear northern boundary.
Building to have minimum setbacks from sewer main of 2.50m to be clear. Or no closer than 0.60m with piles under foundations to below sewer main invert level (approx. 0.60m AHD)

The water corp document "protection of services guidelines" will help you calculate the exact depth of piling required. It's easy to find a pdf of (I've linked to it somewhere on this forum) and you may find a cheaper compromise. While working for a consulting engineer, I'd knock out piling designs using this document in about 15 minutes, including tracing the builders shitty scanned drawings. We'd charge bugger-all for them too, maybe $150? (it's been a couple of years.) If you engaged a similar engineer yourself, rather than through your builder, you could ask them to suggest alternate solutions, like maybe moving your wall 1.0m and having shorter piles or something.

Should the conveyancing firm not been able to find that the pipe was there?
I am waiting for them to retrieve my file from their archives and get back to me.

You can find out this information yourself on 1100.com.au. I don't see why your conveyancer would care.

Also what happens in years to come that the pipe needs to be replaced? Do they just come in and dig up the exposed concrete that we will have layed over it and the backyard? Do they replace the concrete and grass?

yes, the just dig it up. If you're lucky, they'll do a half-arsed job at replacing your grass. They won't do anything to replace paving or concrete. (I had a friend that had to move his garder shed for them)

Any thoughts or expertise in this field?

Regards

I'm not an expert. I'm probably wrong on a couple of points. But I don't think I'm far off.

 

[Jake D]

I cant comment on your question here,but i can comment dealing with sewer lines with government departments is a mine field.I am in S.A. and have a sewer querie,8 different phone numbers,3 different departments and 3 hours on the phone,with not one answer.I did get a email response from SA Water...........Unfortunately we have no internal drainage plans for your property. Sorry for any inconvenience caused.

In Perth Metro, the process & communication is usually very clear and easy.

I just realised I'm only assuming this is where the property is located, based on Regrow's profile location.

 

[Jake D]

http://www.watercorporation.com.au/_files/PublicationsRegister/1/Protection of Services Manual.pdf

 

[handyandy]

It is 1mtr in from the rear and is approx 2.2mtrs deep and runs across the width of the block........

Our house plan is setback 1.5mtrs from the rear and left hand side fences.

There is a 150VC sewer main approx. 2.20m deep running on a 1.0m alignment inside the rear northern boundary.
Building to have minimum setbacks from sewer main of 2.50m to be clear. Or no closer than 0.60m with piles under foundations to below sewer main invert level (approx. 0.60m AHD)

Also what happens in years to come that the pipe needs to be replaced? Do they just come in and dig up the exposed concrete that we will have layed over it and the backyard? Do they replace the concrete and grass?

Based on the dimensions provided for you to not have to do extra peering you would need to be 3.5 - 4 meters from the back fence.

Even with piers say 3 meters deep you will still need to be 1.6 m from the back fence.

Conveyancer couldn't care less about the sewer pipe. They didn't know how you wanted to place the building. The sewer pipe is only an issue now that you want to set the building so close to the back fence.

$5k would seem reasonable for peiring the slab down 3 meters. Remember this should be everywhere under the slab as the bottom of the foundations should have the same sub soil conditions and base. By doing this you will end up with a superior building ie more solid foundations.

Cheers

 

[devo76]

My sewer was 3.6 meters deep. I had to encass the entire line within the zone of influence.( fence to fence 20 m). That cost $14,000. the house slab within the zone of influence was increased from 100 mm to 150 mm thick with piering every 2 meters to below the zone of influence. $3,500 extra in concrete.

My place will not move.

 

[RPI]

Can you approach them about diverting the sewer. 150 is not that big of a line. When we do unit blocks with basement carparks it gets rerouted. They don't like doing it for build over but if you can reroute it and meet regulations it is often cheaper, no concrete.

D

 

[Jake D]

With the quoted cost of piling only being $5k, I don't think the cost and time and effort of first convincing water corp, then re-routing the sewer would be justifiable.
Also, if it runs along the back fence, where else could in go? A meter or so into the rear neighbours yard with no benefit to anyone except OP?

 

[Jake D]

What was the outcome, OP?

 

[westminster]

BTW it isn't your conveyancers job to alert you to the fact that there is a sewer line on the property.

I check all my properties for sewer line easements before putting in an offer. Sometimes the selling agent will alert me to it, sometimes they don't. I always check by ringing the Water Corp.

Your piling quote is about right but by rejigging your house design you might be able to not pile at all.

 

[bondibouy]

If you re-route the sewer line and it is currently run at minimum fall then you are unable to get the correct fall as the sewer line is now longer.
The wate authority has the right to access the sewer line for repairs at anytime and also remove any structure that impedes access.
The quote for the piers is reasonable.