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We have a job were a 35kpa runs under a slab of a building about 15m long I cant really find any clear definition if this is allowed it is the existing main installed in 1997
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hi newby, talk to the people who installed the main they should have all the answers,cheers
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Paragraph 2.4.3.12 of NZBC 5261 clearly states that gas pipe embedded in concrete SHALL NOT exceed 7kpa (other circumstances also apply). Correct me if I am wrong by my understanding of the law is that as soon as you touch that pipe you are responsible for the complete installation. If they are not willing to reroute the pipe as per NZBC I wouldn't touch it.
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NZS 5261:1996 was the applicable gas installation Standard in 1997. The current 7kpa pressure limitation applicable for pipe work buried either under or in the slab did not apply at that time.
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its not under a slab yet but will be in about 2 weeks it is just currently under the ground about a metre deep
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@ plumber it states embedded in concrete but this pipe wont be. there is no statement or information for in ground under slab.
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If its underground then rule 2.4.7 applies. Just need to establish whether its subject to traffic or not.
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yes I read it like that to and therefore dont see it as a problem there is no traffic and finished ground level will be almost 1m above the pipe.
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would the gas fitter be expected to accept the durability issues that would then come into play with the pipe now being inaccesable therefore under the B2 requiring 50year durability?
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What are you connecting to that gas main? When you say main, is it the pipe the provider installed or is it the main run from the meter?
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sorry it is a 63mm pe pipe run from the meter across to the rear of the property
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If you are connecting onto it then yes you will be made responsible in future if anything goes wrong as you will be certifying the complete system (including the underground pipe). This means that you the Certifying Gas Fitter are taking responsibility for the complete installation.
I'm not sure if getting your client to sign a document excluding you from any responsibility on that gas pipe is actually leagal, its like getting a costumer to sign a document excluding a plumber to take responsibility for an installation for not installing a tempering valve because the client didn't want to pay for it. Then something happens... (we have to install a tempering even if there was no tempering valve before replacing the HWC)
I believe you need to advise your client that certain tests need to be made ("charge up" of course :o) to ensure the pipe is installed correctly and safe. Tests such as a pressure test or even a camera down the pipe (you can messure the level from the ground as the camera is pushed through) to determine whether its laid straight (no dodgy bends etc) and the internal condition will give a more confident feeling before signing the dotted line.
In the climate our industry is in at the moment you have to be very careful. Hope this helps. ;)
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The main issue I see at hand is the gas fitter would be acceptinging the 50 year durability of the existing pipe by signing the system off as required under NZBC B2 unless he is to replace the area of pipe that runs under slab with a new pipe. Other than that I do totally agree with everything else you have said I cannot find anywhere the reference a gas main of any pressure cannot be run under a concrete slab as long as it meets the durability requirments as stated in the B2
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Absolutely right, Install a new pipe. Alternatively I'm not sure but I had a case where the engineer signed off the system. Maybe worth exploring.
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Im starting to find this interesting I have had someone come back and say that PE pipe cannot be installed under a A floor Slab at all
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PE piping systems shall be installed in accordance with AS/NZ 2033 or the manufacturers instructions. Later I will also attach the Guide for Safety with Underground services you can also look at G10 here on the forum good info there as well.
AS3500 refers to such cases being a subject to the engineers approval.
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I have been informed that itis better outlined in the nzs 5601 but dont have a copy to check this against
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AS/NZS 5601.1 table 4.1 no PE pipe over 7kpa to be laid in the ground under the building
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We continue to live and learn, there it is very clear. Cheers for sharing that. :)
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Fairly sure that if the pipeline in pe is run within a conduit, it can go under the floor slab. Think of the thousands of installations with PE that run under driveways and slabs etc....Best bet, call the gas board, they'll set you straight and you wont have to worry. Make sure you get them to send a letter in writing confirming the course of action to take and file it in with the paperwork of the job.
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Also forgot to mention....I'm not sure any craftsman is allowed to play with 7kpa and above, so be very careful not to touch anything and call the board.