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Underground piping for sprinkler systems 2

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hawker5

Specifier/Regulator
Jan 28, 2011
5
Does anyone know how deep underground piping (for sprinkler systems) should be when it passes under a building foundation? I am having difficulty finding this information in NFPA 13. Any help on this would be greatly appreciated.

Thanks
 
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Thanks Eddycurrentguy.

I live in Toronto, Ontario, and am using the NFPA 13 handbook, however I am finding it difficult in how deep the pipe should be. It states in NFPA 13 that the pipe clearance shall be provided to prevent breakage of piping due to building settlement, however it does not say how deep under the building foundation it has to be. I am curious to know if there is an actual number or is this the basic rule that is used normally?

 
This question is how deep must the pipe be...your other question was asking us to size the pipe for you.

Please note that these forums are for interactive guidance between practicing engineers. They are not intended for free engineering. We don't know where you are or what your codes might dictate. Further, we don't know your environmental conditions (depth of freezing, soil types, etc.). We don't know how many sprinkler heads or what type, the geometry of the layout, the size of the layout, the water source, the water pressure or any other relevant design information necessary to assist.

I'm not being harsh, but your questions are so broad and lack sufficient predicate to allow anyone herein to help you.
 
hawker5...you were posting while I was replying. Sorry.

OK you're in Toronto and you want to know how deep the pipe needs to be based on the foundation and settlement.

You need the following:

From the geotechnical engineer, get the anticipated settlement of the building foundation.

We generally like to see about 12 to 18 inches below footings for pipes of small to moderate size (1" to 4"). As the size of the pipe increases, so does the depth.
 
I recommend you contact your local building inspector. They should be able to provide clear direction. I live in Michigan, USA and many cities have ordinances that exceed national code for sewage, electrical, etc. In most cases city requirements exceed national requirements. To add to the fun, each city has requirements that vary from the others. Besides, last thing you want is to find out that while you met the national code, you didn't meet local ordinance.

I sae you had a few other related posts. Probably safe to say that the same theory holds true. Call your local building inspector to be sure.

 
Thank you all.

Your threads have been much helpful. I will contact my local building inspector to confirm more details. Thanks for your help.
 
In general, the pipe should be below frost, and in Toronto for water lines it is over 4 ft (usually 5 to 6 ft. is common for water lines). For new construction, if there is no basement, the footing may be stepped down and the pipe passes through the wall (with a sleeve oversized for potential movement/settlement). Usually, you do not go under the footing unless it is a retrofit job. Then you may have to underpin or use insulation over the pipe, as a last resort.
 
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