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Discussion Starter · #1 ·
I have to run about 35' of underground pipe from the well to my slab. The house has an addition that was added much later and the add on room covers a portion of the original water pipe.

Instead of locating the old water pipe and cutting up 10' worth of slab, what I'd like to do is run the pipe in a new trench (below frost line) directly point A to point B, and bring it up in the newer addition closet wall which shares the outside wall, and run the rest in the ceiling and connect to main above where it exits the slab now. Plan on using copper exclusively indoors and I can just bypass 98% of the slab and hopefully future headaches as it appears the floor was cut once already.

What I need to know is how far under and in the slab does a water line typically need to be brought in BEFORE going "up?" So I bring the pipe under the slab, does it need to travel a certain distance before you are able to make the 90 degree turn? And does it need to maintain a 3' depth under the slab?

Thanks.
 

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Sketches would be useful, if you've got them. I think that the answer to your first two questions depends on the depth of frost where you’re located, since you want the line to travel far enough under the house to never encounter frost. Is that the 3’ that you mention?

When you mention putting the main water supply in the ceiling, is this a two storey house, so that is a place where it never (normally) freezes?

Chris
 

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My copper water line comes up in the insulated 2x4 wall of my garage. I live in Tucson so the garden hoses get stiff a couple of times a year. Where you live will have a lot to do with the placement of the water line to freezing temps.
 

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Discussion Starter · #4 ·
Frost line is supposedly 36" so I'll run the line closer to a 4' depth.

House is weird so bear with me. It was originally a flat-roof home built in early 60's with roughly 30' x 4" x 8" ceiling beams 4' apart, spanning entire width of the house with I think 10' high ceilings. A pitched roof was later added, so the original flat-roof is now the floor of the attic. Bedrooms and main hallway + rear addition, have lower drywall ceilings added later on that conceal the 4" x 8" beams in that section of the house, so there's roughly a 9" cavity between the dry wall and original tongue and groove bead board ceiling. I wanted to run the new line tucked up against one of those 4" x 8" beams in the cavity and drop it straight down above where the main exits the slab now. It's a straight shot from the addition's closet to the the water main coming up from the slab.

So entire water line inside the house will have warmth inside the ceiling cavity and I'll throw fiberglass bat up there as most of the drywall was done poorly with cheap popcorn effect and needs redone anyways. Attic floor has fiberglass bat already.

I have a 1-man post hole auger with extentions, so was thinking of digging out a 4' hole below footing, turning auger sideways, and boring a 2" hole just big enough for the pipe to fit through under the slab, so as to avoid disturbing too much soil under the foundation. Then run a concrete drill bit through the slab and bring the line up. Just need a rough estimate of how far into the house the line should be before drilling into the slab to bring the pipe up.

We get sub zero temps that can sometimes dip to -10 for brief periods, so was concerned if I drilled too close to the exterior wall, the line might not see the same level of protection if the cold can penetrate beyond the footing or immediately under the slab.

Sorry, no drawings. Everything is in my head. Own house outright and would rather diy for a couple hundred in parts at most vs. several thousand + from a plumber that'll probably insist on leaving it in the slab then charge another couple grand to cut it. Already fixed well casing and ran a new SS pitless last summer (rpitfa job but did it) and noticed then the water line had been monkeyed with and re-run at some point more recently, and NOT done correctly (plastic line with 90 degree elbows everywhere and loose worm clamps, etc., and would like to run all sweated copper. Also getting overly saturated ground soil so have to do this soon as it's bleeding out somewhere.
 

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Discussion Starter · #5 ·
If this was a new house on a slab with a private well, in an area that sees regular below freezing weather during the winter, how far inward does the water main need to be before bringing up through the slab? Anyone?
 

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Discussion Starter · #6 ·
Does this not matter? Right now the main comes up in the center of the house so a long stretch is in the slab which I'd like to abandon and bypass. Is it OK to bring it up around 3' from an outer wall instead?

So new water main from well to house, 48" deep. 48" deep hole at footing to get auger sideways. I bore a roughly 2" OD vertical hole UNDER the slab say 3' in, then do a 90 degree and drill a hole through slab and bring up the main.

So instead of main coming up through slab some 15' from the exterior wall facing the well, I bring up 3' from that wall. Is that far enough into the house to avoid freezing or should I try and do 48" in?
 

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Here is a recent thread that deals with something similar. There is an article that I linked to in post #6 that shows (Figure #5) how the temperature gradient looks under the slab of a heated space. I got the impression from your earlier posts that you were proposing to come up immediately inside the foundation, but if you plan to stay horizontal until the pipe is 3 feet inside the foundation then the pipe won’t experience any frost on its way up through the slab.

Out of interest, do you know how deep the existing line is buried? And how far did the line ran under the slab before turning vertical before the addition was built over it?

Scanning back through your posts, you might start a new thread and ask for advice on what the best pipe material to use is. Copper won’t survive if an odd weather event happens to freeze the ground lower than you anticipated. There are other materials that will.

Chris
 

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Discussion Starter · #8 ·
Thanks for that Chris. I have the option of bringing it right up in the closet which is about 36" x 36" and shares the exterior wall and just wanted it to be doable w/o cutting the floor or having it freeze up. The giant beams in the ceiling limit my options so the closet is best spot.

Existing line is around 36" deep at the pitless adapter on well casing. Considering the hack job of plastic line, elbows, and worm clamps I saw when replacing the pitless last year, not entirely sure how deep they ran that across the yard or if they even observed a 3' min let alone 4'.

Seems line was about 16' inside from original exterior wall but kitchen and bathroom are in the center of the house, so line being 16' inside is a few feet from both. No idea if this is original to the house though or changed later. Addition adds an extra 12' to that.

I'm bringing in dirt to raise a portion of the yard a few inches due to poor slope drainage, so well casing will have a few more inches of dirt around it. Will run line deeper though just to be safe.

I was actually going to post another thread about water lines to be 100% certain closer to doing the job. Whatever goes in, I don't want to touch it for 25 years or more if possible.
 
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