Forums > Specific Focus > Home, Garden & Construction in Mexico

Derek

Oct 18, 2001, 7:15 PM

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buried copper pipe

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I have been inspecting the construction of a residence and noticed that the rigid copper water pipe is laid on the floor then concrete encased. Is this standard in mexico? Concrete has a lime base which over time will deteriate the copper pipe causing a failure. Why is not poly pipe used?

Loco

Oct 19, 2001, 8:43 AM

Post #2 of 9 (3873 views)

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soft copper pipe in cement

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is common in a water heated floor. don't know about the chemical reactions

Jim in Cancun

Oct 19, 2001, 9:39 AM

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"Because copper is better"...

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RexC

Oct 19, 2001, 9:18 PM

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Effect of lime on copper tuning is negligible

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The effect of lime in the cement corroding copper pipe is negligible, of more importance is to prevent electrolisis from taking place. It is critical to keep the copper tubing from being in contact with any steel, or iron. Do NOT let the copper contact any rebar, or wire. Copper tubing comes in three thicknesses. The thinnest is type "M", then the most commonly used thickness is type "L" , then the thickest is type "K". Some US codes require type K for buried installations.Buried copper is usually soft type L, soft copper rolls can be obtained in type K also, but is not manufacted in type M. Soft copper rolls are 60 feet in length, hard copper comes in 20 foot lengths, so you would have a soldered joint under the slab every 20 feet, at least. It is NOT good practice to have any soldered joints under the slab. It is a lot easier to open a wall, than it is to break up a cement floor, assuming you remember where all the joints are, in case of a failure. If it is done right, there will never be a failure. Using local labor, that is sort of an unkown quality. If you have a long run, it is good practice to bring the tubing up in to a wall, make your soldered joints, and take it back under the slab. That is not easily possible when using hard copper tubing. You would need to heat it to anneal it, for bending. The 20 foot lengths reduce the chance that you would be at a wall when you wanted to be. It is common practice in The US to try to keep the tubing UNDER the slab where possible, not in it.Remember, you must avoid the chance of electrolisis at all costs. If the tubing is in contact with any ferrous material, it may last for many years, and it may fail in as little as one or two years.I do have some expertise in this area. I retired last year, after 47 years in the United Association of Plumbers and Pipefitters Union. There is a five year apprenticeship with 10,000 hours of experience, and 1000 hours of classroom study to qualify as a journeyman in my union. When I went through my training in the 1950s, we even received college credit for the classroom work. Since most local unions have now built their own schools, they are not accredited, and college credit is no longer earned.RexC 
: ...just ask almost anyone--including engineers, architects and hardware people. (Even some PVC salespeople) Copper wire is also better than the "new-fangled" aluminum stuff for high tension and the way we have done it before is better than any new "untried" idea.: (Based on my personal experience.)

Derek

Oct 20, 2001, 4:04 PM

Post #5 of 9 (3872 views)

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soft copper pipe in cement

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Thank you for the comments submitted. In this case the copper is hard type, with soldered joints buried in the concrete.Is this acceptable to the building code.
Derek
: is common in a water heated floor. don't know about the chemical reactions

BillBenn

Oct 28, 2001, 5:35 AM

Post #6 of 9 (3872 views)

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Electrolisys on Copper tubing

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A few years ago, my sister begain to have repeated pinhole leaks in the copper piping in her rental house, usually behind a sheetrock wall, which caused expensive repairs each time. I looked all over the house, and found that someone(the Doofus renter, probably) had disconnected the ground wire from the hose bib. This ground wire needs to be connected to a rod, driven 3-4 feet into the earth.Anyway, problem stopped!!

BillBenn

Oct 28, 2001, 5:35 AM

Post #7 of 9 (3872 views)

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Electrolisys on Copper tubing

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Richard

Oct 31, 2001, 12:48 PM

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ReGround rods by NEC

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Is to be 10 ' into the ground. Here in the states if you have city water you should also ground panel to the water meter and jumper across the meter to the main line running to the city.

Caroline

May 26, 2002, 11:34 AM

Post #9 of 9 (3873 views)

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Effect of lime on copper tuning is negligible

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That has not been my experience that the effect of lime is negligible. Where I live the copper tubing is placed in ordinary black pipe. No more problems.
: The effect of lime in the cement corroding copper pipe is negligible, of more importance is to prevent electrolisis from taking place. It is critical to keep the copper tubing from being in contact with any steel, or iron. Do NOT let the copper contact any rebar, or wire. : Copper tubing comes in three thicknesses. The thinnest is type "M", then the most commonly used thickness is type "L" , then the thickest is type "K". Some US codes require type K for buried installations.: Buried copper is usually soft type L, soft copper rolls can be obtained in type K also, but is not manufacted in type M. Soft copper rolls are 60 feet in length, hard copper comes in 20 foot lengths, so you would have a soldered joint under the slab every 20 feet, at least. : It is NOT good practice to have any soldered joints under the slab. It is a lot easier to open a wall, than it is to break up a cement floor, assuming you remember where all the joints are, in case of a failure. If it is done right, there will never be a failure. Using local labor, that is sort of an unkown quality. : If you have a long run, it is good practice to bring the tubing up in to a wall, make your soldered joints, and take it back under the slab. That is not easily possible when using hard copper tubing. You would need to heat it to anneal it, for bending. The 20 foot lengths reduce the chance that you would be at a wall when you wanted to be. : It is common practice in The US to try to keep the tubing UNDER the slab where possible, not in it.: Remember, you must avoid the chance of electrolisis at all costs. If the tubing is in contact with any ferrous material, it may last for many years, and it may fail in as little as one or two years.: I do have some expertise in this area. I retired last year, after 47 years in the United Association of Plumbers and Pipefitters Union. There is a five year apprenticeship with 10,000 hours of experience, and 1000 hours of classroom study to qualify as a journeyman in my union. When I went through my training in the 1950s, we even received college credit for the classroom work. Since most local unions have now built their own schools, they are not accredited, and college credit is no longer earned.: RexC :
: : ...just ask almost anyone--including engineers, architects and hardware people. (Even some PVC salespeople) Copper wire is also better than the "new-fangled" aluminum stuff for high tension and the way we have done it before is better than any new "untried" idea.: : (Based on my personal experience.)

buried copper pipe

soft copper pipe in cement

&quot;Because copper is better&quot;...

Effect of lime on copper tuning is negligible

soft copper pipe in cement

Electrolisys on Copper tubing

Electrolisys on Copper tubing

ReGround rods by NEC

Effect of lime on copper tuning is negligible

"Because copper is better"...