View Full Version : water to woods cabin
12-29-2008, 10:57 PM
I have a small cabin in the woods used for the occasional get away. I would like to run a branch line off of the water line that services our main residence. The line servicing the main residence is 1 inch, the distance to the cabin is 1300 ft. & I would like to use pex. The cabin will have a shower, toilet, bath sink, & kitchen sink. Can I run a 1 inch or 3/4 inch line this distance and have a reasonable volume? All thoughts and suggestions are greatly appreciated.
12-30-2008, 02:42 AM
Too small. 1" pex ( equivalent to 3/4 PVC or copper) would incur 30+ psi drop over 1300 feet, depending on gpm.
I would use 1 1/4" polyethylene or PVC.
01-27-2009, 08:34 PM
Thanks for your help. Sorry my thanks took so long. My project is slowly creeping forward. I requested prices on polyethylene from a pipe supply store and they recommended 1.5. According to them the fittings for the 1.25 are not as easy to find. I am assuming that this will work just as well if not better.
master plumber mark
01-28-2009, 05:21 AM
Being a cabin, 1300 feet away.
are you planning on burying the water line
deep in the ground for winter ???
or just something close to the surface...??
are you going to have to be tearing up
some nice trees in this effort???
1 1/4 seems like a daunting task just to get water back
to something you are probably going to us on occasion..
how about more information...
you can get a awfully long crestline poly pipe
1000feet in one roll if you stick with 3/4. it just depends.
01-28-2009, 10:38 AM
I grant you it is just a cabin but I want to equip it for extended stays. Could be used for guests or who knows, a deer hunting cabin. So water is needed and a well will cost about $7000, hence my choice of an $1100 water line. And yes I will bury it about 20 inches deep. Enough so that some day if someone plows the area it crosses it will not be cut.
Small bath with water heater, shower, stool, & sink. Kitchen sink only.
There will be a septic system to accommodate all of this, don't want to soil what we are trying to enjoy.
As for trees, there are "thousands" and not a single one will be damaged by cabin placement or septic system. Heck I've even been careful not to damage root balls. Hows that for conservation :)
My bottom line question has to do with pressure and volume. As to pressure I am willing to contend with whatever as long as it is realistically functional.
01-28-2009, 11:12 AM
Because of the 1300' and friction and any elevation losses, I agree with at least 1.5". You can normally buy up to 2" in 1000' rolls and I've never heard of 1.25" fittings being hard to find, that 'pipe supply' doesn't want to stock them. All submersible pumps and deep well jet pumps use 1.25" fittings. The 1.5" fittings should be harder to find but you only need 3; one 1.25" insert x 1" Male of female PT, a 1.5" insert x insert coupling and a 1.5" insert x whatever size female or male for the cabin connection.
I suggest a 1000 roll and a 500' roll and 160 psi or if you are going to bury it in rocks, 200 psi but you must protect either from sharp edges below and above it. And let it wander side to side in the ditch (for contraction/expansion) as you unroll it along side the ditch.
01-28-2009, 11:40 AM
So Gary, you suggest (160 psi in sandy soil) 1000' + 500' + fittings, negligible elevation change, connected to a 1" service line.
What happens at the other end when I turn the water on?
02-18-2009, 05:25 PM
Cabin is currently being built. It was suggested that I could use a booster pump if the pressure was not quite what was needed. So will layout the line in such a way that I can add the booster later if needed. Any thoughts?
02-19-2009, 06:19 AM
What happens at the other end when I turn the water on?
If you use large enough pipe, water will come flying out as fast as you need it. Without any elevation changes, friction loss in the pipe is the only thing that will restrict the flow. Use large enough pipe, and you will have the same pressure at the end of the pipe as you have at the beginning. You will only need a booster pump if you use too small of pipe.
If you install too small of a line AND use a booster pump at the cabin, you will starve the pump and destroy it because of cavitation.
02-19-2009, 04:36 PM
I have appreciated all of the advice given to my quest for answers. My understanding of pipe size and water pressure is more limited than I thought. But I am at last feeling more comfortable with my decision to run a water line to the cabin. I will measure the psi at the main house this weekend.
03-08-2009, 08:19 PM
70 psi at main line. A local supply house told me they have 2 inch PVC gasket pipe for 43 cents per foot. This is about a $350 savings over polyethylene and 1/2 inch larger.
03-09-2009, 11:15 AM
Overall, taking fittings into the equation, PE is the slickest material for water line use, meaning that it has the least friction loss. And with only 70 psi, IMO you need the least pressure loss you can get. All materials will have a pressure loss and so will each joint. If this were me, I wouldn't attempt to save $350 and then maybe have to live with a bad outcome. You unroll PE pipe into the trench as you walk along side the trench. Anything else and you install a fitting every 20' and, with PE you don't need to do anything for expansion/contraction problem and you do with everything else because the PE wanders from side to side in the trench. And two guys can handle a 1000' roll of PE while 1300' of 20' lengths of PVC requires a lot more handling, time and effort to install. And don't forget the cost of the cleaner/primer and cement if needed. And rocks/stones will bust PVC where PE bends and gives a bit but you should have a smooth bed and backfill with either PVC or PE but PE is much more forgiving. The $350
Here are links about friction loss of both. The one link is banned I guess...
03-21-2009, 02:09 PM
The first and most worrisome part is now completed. The advice I received was invaluable. I switched back to 1.5 polyethylene as a result of Gary’s last comment. The pipe supplier was one 500 foot roll short when I arrived, they had 7 the day before. After much discussion I ended up with 2 inch pe at a lower price than quoted for the 1.5.
Observations: Get your ducks in a row before renting a trencher, brass fittings are not cheap, larger pipe wrenches needed for the fittings are, 500 ft rolls of 2 inch pe is a two man job though I managed them alone, cows will migrate to the new pipe resulting in a nice brown coating.
End result is that I have the same 70 psi at the end as the beginning, and as valveman said, the “water will come flying as fast as you need it.”