Author Topic: How hard are these things to do? Run PEX thru yard for water,cut slab for drain?  (Read 3790 times)

Marvel2017

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So I feel like plumbers act like they can charge high amounts for this type stuff, but is it really that hard? I have tools or can rent them from a local place so I'm wondering how hard is it to:

-Run PEX through the yard to add water to an outbuilding. Needs to be 2 feet down (do I need to use a big trencher or can I use that machine that slices through the yard and installs PEX?)

-Cutting the concrete slab for drains for shower and toilet. I've seen youtube videos and I have the tools needed like grinder, air hammer or can rent a jackhammer if needed. I get a lot of "oh, you have to cut the slab for that and it will be extra". I understand labor involved but it's a conventional slab so I'm assuming it's just manhours chipping/cutting away at it with tools until there is enough room for the drain, am I wrong? I would rather use my manhour than someone charging $100/hr

I understand people need to make money but I feel like a lot of this stuff doesn't really take a huge amount of expertise and need a high dollar person to do it=I would like to save money where I can.

Please, any advice is greatly appreciated!

ncornilsen

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Most people in the skilled trades have a vested interest in convincing everyone that what they do is hard, takes tons of experience, and can have dire consequences if done wrong. Its complete bullshit and rent seeking. Now, Industrial stuff is a different thing altogether, I'd be leary of someone trying to DIY a Hydrogen Flouride line.

Anyway, for residential stuff, anyone with an ounce of common sense can do it right.

Now, for your specific questions.  I suppose you could use the machine that slice into the ground to install the pex, but depending on your soil, it may be rocky enough that a buried rock will eventually make a hole in the PEX. I'd dig the trench and lay the pex in a bed of fine sand.

Cutting the concrete slab is entirely a manual labor thing. You need to be careful you don't cut into a hidden water pipe, but other than that, renting a concrete cutter, a few pry-bars and a sledge hammer can do that in no time.

MetalCap

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Just a quick aside, depending on where you live the 2013 winter showed 2' down is insufficient for water lines.  If you're fine replacing it if we have another 100 year frost, then 2' is fine.

The tool you use for the trench is a matter of money and time (isn't is always?)  You can use a pick axe if it's easy enough, or even a small ditch witch from HoDepo.

With any type of water line, have an interior valve if possible to shut off for the winter or repairs.  This is really easy for pex and will save you from a back yard skating rink if it bursts. (5 bucks= worth it).

For the slab you can even rent a jack hammer if you so wish but before you do that.  Make sure you know what is under the slabe.  A shower drain will need a P-trap under it so you need to make sure you don't undermine the slab by digging out too much from under it.  Have gravel on hand to fill in the voids and prevent settling/cracking.

Also you don't mention drainage, I'd keep these in two trenches at least 2' apart.  It's good practice, code acceptable and makes repairs easiy when you're not worried about exposing the other pipe.

Good Luck and enjoy the sweat!

Marvel2017

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100 year frost? I'll be dead in 100 years, so I won't care then. haha jk it's something to consider, thanks for mentioning. I'm in TN so I'll look into it.

I do have a pick ax, but it would be a 70 foot trench. I can rent a trencher for $150/day locally
I've had the yard marked/located so I (theoretically) know where everything is. The slab is 25'X25' 6" deep with a 12" turndown on the perimeter, no pipes inside, just rebar/reinforcement. (it was built to hold a two post auto lift so it should keep its integrity since I'm only cutting out a small area). Luckily I have all manner of tools from when I did a complete tearout of a bathroom down to studs and plywood floor for a friend and redid the whole thing for him.

I'll probably buy a plumbing book and talk to local codes. I can get the permit myself and do the work if it's under $25k locally. Thanks!

Glenstache

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Nothing you are mentioning is difficult, just labor intensive. If the slab cuts need to be clean, you can rent a concrete saw. Jackhammering a long trench through 6 inch slab will get old fast, especially if there is a lot of rebar. Make sure you size your PEX appropriately for the friction losses over your pipe run length so that you don't end up with wimpy water pressure.

+1 on the bedding sand around the pipe and being smart about the discharge line.

Spork

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This all depends on how much time/labor you want to throw at it.   I've done 50+ foot trenches with a grubbing hoe -- but I live in very soft sandy soil.  I can knock it out in a few hours.

I've also cut concrete with:
* angle grinder/masonry blade
* standard circular saw/masonry blade
* masonry bit/hammer drill and a sledge hammer

It depends on how much you need to cut.  If you are moving a fixture a few inches, a drill and a hammer and some time will do it.  If you're cutting a 50 foot trench in 6 inch concrete, you'll kill yourself trying to do it that way.

Side comment: seems obvious, but wear hearing protection and a dust mask.  Especially if you're not using a wet saw of some kind, you will generate a crapton of dust.  If you're doing this indoors, take the time to hang plastic sheeting around your work area.  If your wife comes home to find you grinding away at a high spot on the concrete, taps you on the shoulder and you turn around and cannot see her 2 feet away... she might be pissed.  Yes, I have real life experience with this.  Concrete dust is super fine and will just get everywhere.

DarinC

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You can rent or buy a trencher, but a good rock bar and a trench shovel will do fine if you have the time and energy. For the concrete, I'd try one of those worm drive circular saws from harbor freight with a good diamond blade and something providing a little water where you're cutting to make things easier. It can be a valve/line connected to your water, or just a friend with a water bottle.

http://en.wikipedia.org/wiki/Diamond_blade#Cutting_with_or_without_water
« Last Edit: March 11, 2015, 05:29:11 PM by DarinC »

savman

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Cutting concrete it easy....with the right tools. If you do in fact have a six inch slab, you can forget the angle grinder and circular saw suggestions, neither one will come close to cutting through the slab. (If you had very little cutting, like a 12" x 12" small area you could get by with a circular saw but it would be dicey.); you need something that will hold a 14"blade and has the power to turn it in concrete.  You will need to rent a concrete saw; you can either get a hand held cut off saw, or a walk behind saw.  If you aren't well experienced with power tools and pretty strong I don't recommend a cut off saw. It's basically a motorcycle motor with a blade attached to it. Pretty dangerous in the wrong hands. I have personally seen grown men carted off in ambulances due to kick back. 

If you do go the concrete saw route, you may want to look on ebay for a blade like http://www.ebay.com/itm/14-Inch-Dry-or-Wet-Cutting-Segmented-Saw-Blade-for-Concrete-and-Brick-1-Arbor-/150848068406?pt=LH_DefaultDomain_0&hash=item231f3edb36 Pay attention the the arbor size of the saw you are renting.  Most rental places won't rent you a blade, and they have an absurd mark up on consumables like blades. Expect a concrete blade at the rental store to be 150-200 or more. 

Make the cuts in the concrete about 1.5 to 2 inches deep per pass. Trying to cut the full depth is a recipe for failure. Take your time. Most walk behind saws have water hose attachments that will keep the dust down and extend blade life. (oh yea, the rental house might have a cart for a hand held saw; I would let price be the deciding factor if that's the case.)

As far as a jackhammer it just depends how much you have to remove. A large sledge hammer will do the same job. Me/my employees have demolished thousands of square feet with one. It just depends how much you have to do at once. Get the biggest one you can lift; not one of those toy 8-10 lb hammers. Electric jackhammers are the next best thing and you should be able to rent one where you get a trencher and saw. Weight is your friend; get one that weighs at least 50 or 60 lbs. If you really have some concrete to remove you need an air powered 100lb hammer with a portable compressor that has enough cfm to run it. You shouldn't need one that big. 

As far as the trench; 70 feet can be a lot or a little depending on your soil. I can tell you where I live in GA, that is more than I would personally want to do. But 150$ is a lot for a trencher. (plus most rental houses have loads of fees on top of the advertised rate.) A good man could dig that with a mattock and a trench shovel in a few hours.  You might consider hiring a laborer, a real laborer not some kid, for a day at around 10 or 12 bucks an hour and let them dig the trench and help you bust up/cart off the slab. It would be 100$ well spent if you have someone who can really work. 

Pex isn't popular in my area so I don't know, but make sure whatever you are putting in the ground is rated for underground use and will pass inspection. Also, some municipalities like to see the pipe in the trench uncovered for inspection, so bear that in mind as well. Ask your building dept. 

Spork

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Cutting concrete it easy....with the right tools. If you do in fact have a six inch slab, you can forget the angle grinder and circular saw suggestions, neither one will come close to cutting through the slab. (If you had very little cutting, like a 12" x 12" small area you could get by with a circular saw but it would be dicey.); you need something that will hold a 14"blade and has the power to turn it in concrete.  You will need to rent a concrete saw; you can either get a hand held cut off saw, or a walk behind saw.  If you aren't well experienced with power tools and pretty strong I don't recommend a cut off saw. It's basically a motorcycle motor with a blade attached to it. Pretty dangerous in the wrong hands. I have personally seen grown men carted off in ambulances due to kick back. 

I've done it.  Not impossible.  But: wouldn't want to do 50 feet of it.  You don't need a full 6" deep cut.  If you get a 3" cut and hit it with a sledge, it will be fine.  Yes, slightly uneven below grade but you get a nice clean 3-4 inches.

I've done an area that was probably 20 feet .... and non-linear.  It was stamped concrete made to look like bricks and I cleanly cut out parts and patched it.

savman

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re: circular saw; yea it's not impossible, but the reason I says it's dicey (aside from the fact it's just going to plain out suck - like you say you wouldn't want to do 50 ft of it -) is a 7.25 inch circular saw is only going to have a depth of cut of ~2.5 inch. While it's true you don't need to cut all 6 inches (a 14" blade on most saws doesn't even have a 6" doc) 1.) The further you cut the easier it is to break out 2.) Slabs, especally residential slabs, easily vary in thickness .5" and sometimes around 1"