Plumbing

[builderboy]

I'm using the 14x24 builders cottage plan with frost wall/crawl space foundation. I'm wondering how to route the kitchen sink drain over to the bathroom area where all waste water will exit to my disposal system. Normally plumbing would be under the floor overhead in the basement but I'm talking freezing crawl space. Seems like a long run of pipe (maybe 9-10 ft) to try to keep from freezing. (I'm can just hear the little lady when the sink backs up!!) I'm thinking I really need to minimize the amount of plumbing exposed to cold crawl space!!

[glenn kangiser]

Can you insulate the outside perimeter of the cabin by a combination of vertical and horizontal foam board enough to keep the crawl space from freezing - also can you use the closed crawl space information to close it and keep it from freezing?

[youngins]

I have the Builder's Cottage plans, but don't remember seeing "frost wall/crawl space foundation" option..

[builderboy]

My plan is the 14x24 plan#C01A April 5, 2001. The crawl space is shown under "Foundation Plan"

[John_M]

I always wondered how much insulation it would take to make sure your crawl space did not freeze.  I too would like to run some plumbing underneath.

Is there an R-value that one would need to reach?  I have 10 inch block walls.  Just a few small vents and a steel entry door.

[builderboy]

I was thinking minimize underneath plumbing so I could tackle keeping the plumbing warm rather keeping the whole crawl space from freezing. I'm a YaBBnewbie here so maybe I'm thinking crazy but a friend with a prefab minihome has underneath plumbing centralized in a small area. He built it in with insulated walls between the ground and underside of the home. The pipes are wrapped with electric heat tape and insulation. The "room" he created (about 4 to 6 sq ft) has a light which he can turn on for heat if it's extra cold. Never had a problem.

[John_M]

My concern is not when I am there, it is when I am not there!

[John Raabe]

The concrete crawlspace foundation shown in the Builder's Cottage plan has the footing at the local frost depth. Some people call this a "frost wall".

There can be several strategies for freeze protection when the house is unoccupied. First off you need to be pimarily concerned with supply lines. Drain lines (except for traps at sinks and toilets) will be dry and open when not being used.

The time proven technique is to drain the lines. You or the plumber should install a drain at the low point of the supply lines so the pipes can be dry when they freeze. Hot water tanks and traps will need to be drained.

Another approach is to keep the house above freezing and let the water run at a slight dribble to keep the line open. This takes energy, of course. As does heat tape on exposed underfloor pipes.

A sealed and insulated crawlspace is a good idea but then the house still must be heated even if the crawlspace stays above freezing.

If you are building in an area where cabins are left for long periods in the winter, check out what other folks are doing on this topic. If electricity is reliable then there are lots of choices. If you are in a hard freeze area and will be without power for long periods then you will likely have to implement some shutdown procedures to protect the water system. This could involve blowing out the traps, draining the supply lines and getting the right kind of shutoff main and have it in a frost protected location.

[borgdog]

In the recreational development I'm at in the cascades of central washington most people only use their cabins a couple times a month in the winter, and don't heat them in between.  Mostly we drain all the supply lines (all built carefully so slope to a low point for ease) and add RV anti-freeze (the pink stuff) to all the sink, tub, and toilet drain traps.  Once you get in the groove it really only takes about a half-hour to get it all done before leaving.  Of course you do want to make sure the kids have all done their pre-trip business before the shutdown else all will be repeated.  

[jraabe]

There you go! Thanks Dan.

Do you find that most folks just leave the electric hot water heater on and realize that it would take a pretty long power outage to freeze the tank?

[borgdog]

Mixed on the electric water heaters, some drain them, some leave them on.  There's at least one couple that do the same "winterizing" but leave their heat on at around 45-50 degrees, they like it to be above 20 degrees in their cabin when they first get there, it does take a while to warm a place up from that cold.

[Amanda_931]

There's a difference between vacation cabins where nobody's there for weeks or months, and coming home from work to find frozen pipes.

My neighbors in the Nashville area (with real crawl spaces, not pier foundations) put things like 100 w lights near the pipes.  So did I when I remembered   (I got good at mending various varieties of PVC pipes).  (I also used a 500 w halogen loading dock light to heat and light my bedroom--it worked just fine and the cats didn't sit on it more than once when it was lit)

But 0 degrees F was pretty rare there.  It did happen more than once.

The bathtub drains just froze when they went out of the house in a duplex I lived in in Southern Indiana.  So that if it looked drained and I took a bath, my neighbors got my bathwater.  And vice versa.  But even though, IIRC it was plastic pipe, nothing ever froze and broke.  Nuisance, though.  Especially if it didn't drain for a day or so.

[MountainDon]

I did something unconventional on my RV that I may replicate in my little mountain cabin retreat. The waste plumbing violates code though; but then ....  :-?

The water supply lines have a permanently installed air line from a small compressor. Turn off the water; turn on the air compressor, open all the taps, then the low point drains, turn off the air compressor. Open the petcock on the water heater and let it drain.

I removed the kitchen sink, bath sink and shower drain P-traps and re-plumbed them all to one P-trap in the RV basement. I pour a slug of polypropylene (pink) RV antifreeze in anywhere and it flows to and fills the one trap.  Elapsed time = about 5 minutes, give or take.   The toilet is a straight dump into the holding tank; it's best left empty. Although it has been rendered into a solid brown block on a couple of "senior moment" occasions.  [smiley=embarassed.gif]

In cold weather I frequently leave the water heater empty and bypass it; leave it empty all the time, unless I/we really need a shower.

Just some off the wall ideas/thoughts. The cabin will be solar electric so I don't want to use any electric devices for freeze prevention, and it will sit unused for weeks at a time in the dead of winter. I do use electric cable wraps in the home workshop building "just in case". They have an thermostat so no power use when not freezing.

PS: the RV basement is insulated and is heated whenever the genset is run (exhaust pipe loop) or while driving down the road (engine coolant water heat)

[Amanda_931]

I believe it's both illegal and  dangerous to use a "regular" compressor to fill SCUBA tanks, because there might be some oil in there--and almost "any" could coat one molecule thick--and block--a lung or two.

Fear of something like that is probably why it's not code for water lines as well.  Although it would be less likely to happen--you'd have to accidently breathe the water that happened to be contaminated.  I think I'd run the water for a bit on startup.

[MountainDon]

All I can say is that most everyone I know with an RV blows out their water lines with a "regular" air compressor. Ditto for taking your RV to an RV service center. RV shops sell little plastic screw-on adapters for this purpose (tho' their all plastic cheap construction leaves some to be desired... I made my own for the RV with a rubber tire valve pushed through a hole drilled in a PVC fitting).

Compressors used for SCUBA tank refilling are indeed very special. They have to be able to fill the tanks up to 3000 PSI, something well beyond the ability of any common compressor, to pick just one thing.  The ones I've seen are multi-stage. They (are supposed to) use a special oil that can not combust under the high pressure... if that was to happen CO is produced and that's a real killer too, especially under high pressure. Some of the dive compressors the Navy uses are oiless.

Most, if not all, of the small compressors like I use for blowing out water lines are the so-called oiless variety, not the ringed piston in cylinder variety with an oil sump. I believe there's more danger to oneself from inhaling oil from any number of commonly used spray lubricants, rust busters, and other petroleum distillate based products, than from using the air from one of these compressors to blow out my water lines.

Simply my opinion.