Tuesday, January 2, 2018

Building A Hot Tub in the Woods

For years, I yearned for a hot bath out here at our cabin in the woods.  Ah, the relaxation of sinking into deep warm water, maybe with a book and a glass of wine after exercise or at the end of an eventful day.

But moving, heating, and draining water are all challenges in this setting that I never appreciated when bathing in a city.  In a remote, off-grid home with six months of winter, a cold water well, and no septic system, a bathtub seems like a decadent pleasure in a former, urban life.

After several years of trouble shooting water delivery problems at Latitude 61, we finally felt confident about securing running water ... most of the time - after we re-insulated our well and water lines for improved reliability.  So I started to think again about a tub that could work within our constraints:

a) It would have to be outside, because there is no room in the outhouse, cabin, or shower house.
b) We would have to be able to fill it by hose and then heat the water by wood or propane, during long, cold winters without fear of hoses, couplings, and water freezing.
c) And it needed to be close enough to the cabin that I would even CONSIDER a cold and dry ingress and wet and slippery egress.

The ideal solution was a Snorkel Tub, sold by a company in Seattle, WA (snorkel.com).
Its round shape, of cedar staves (fence-like slats), metal hoops, and wooden lid looks like a giant beer or wine barrel.  City people can connect to power, but remote owners fill the tub by hose from a well and then heat the water by building a fire in an ingenious, submerged metal firebox that takes up about 1/3 of the interior space.  As the metal heats up, so does the surrounding water. The fire is accessible through a metal lid, fitted with a square, sliding, damper.  Smoke exits five feet above the bather through a metal chimney.   Feet are protected from the metal firebox by an underwater wooden fence.

I leafed longingly through the catalog of  options,  (some in gorgeous locations, of course) but the high price point was a real deal breaker for me.  Would I use it enough to justify that cost?  How about ... Brrrrr.... during the dark and cold days of winter?  Would hoses freeze and burst? Could we drain it through the snow?  Finally, how much time and wood is required to heat the hundreds of gallons of 55 degree well water in Alaska temperatures?

Discouraged, I explored cheaper, do-it-yourself options, such as tubs made from horse troughs and old metal or ceramic tubs set over sand pits with fires banked within them.  However, many options seemed fraught with endemic problems. (How about boiling like a frog in a metal container set above a fire?)  Others were impractical for our setting. (How to access and maintain a ground based fire in 3 to 8 feet of snow?)

Ultimately, as it often can, desire overcame frugality.   Like the money we spent on an excellent mattress and locally built furniture, I justified this purchase as a quality- of- life enhancement that we would, I hoped, enjoy for decades.

Because of our location, we planned this project a year in advance.  For a tub sized 5 ft round by x 4 ft deep, we marked out the space adjacent to our back deck (for above-snow access), next to an exterior water spigot, and situated with pretty views of the lake and surrounding woods.  Over the summer, we hauled load after load of lake rocks up hill and dumped them into the marked circle to form a a base.  We ordered the tub,  which arrives disassembled, for February delivery to the Anchorage port, and for the 1000 pounds of supplies to be packaged in boxes smaller than pallet loads. This way, my husband could manhandle everything onto our car's trailer for the 1.5 hour drive north, and then onto the snowmachine trailer for the 3 hour cross country/frozen river route to reach home.  Since, by this point in the winter, several cords of firewood were depleted, we stored everything in our wood corral until summer, except for 20 - 60 lb bags of cement, which we tarped in the snow by the back deck.

The following July, my husband and son combined batch after batch of cement and water in our small, hand cranked mixer to form a 5 inch thick base over the rocks, further strengthened with rebar.  I hope it will suffice, in this earthquake prone location, to support the estimated 4000 lbs (!) of about 400 gallons of water.   Time will tell.

Assembling the staves seemed like a “Three Stooges” endeavor.  Like liquor barrels, no glue holds the wood together; the bath water saturates and expands the pieces to prevent leakage, and three metal belts hold them together.  That sounds easy, but we found that inserting new staves "here" caused prior ones "there" to loosen and fall out.  To hold it all together, we loosely taped the “wall” while two of us spread our arms around as much as we could reach while the third tapped his way around the barrel.  Alas, at the very end, we stared rather stupidly at a space of one inch wide and a final stave three inches wide. Oops!  We dismantled the whole thing and started over. My patient son tapped each plank more tightly than before and then wedged in the final piece.  Quickly we lifted and tightened the three metal belts.  About an hour afterward, we heard a shot.  It wasn't a gun.  One of the staves had cracked in place under pressure.  Would that cause leakage?  We worried.

The next day, son Kenyon climbed inside and assembled the metal firebox, protective fence, and the three wooden benches, each at a different depth of water.  The final step was to install the five foot metal chimney.

Time to try it out.

This was absolutely the biggest extravagance we had installed out here.  I was nervous about my desire and all the money and time that my husband and son had spent on this  Please... please... make it worthwhile - for more than just me!

WE LOVE IT, in summer and winter.  Yea!

The pressure from our well fills the tub with 55 F degree water in about 40 minutes, after which one can safely light the fire.  As newbies, we overbuilt the first few fires until we realized that the firebox, designed like a rocket stove with a strong downdraft,  was much more efficient than we expected.  The website indicates 60,000 BTUs!  By trial and error, we discovered that in both summer and winter, 4-6 split logs and 3 hours achieve a comfortable temperature range of 97 - 105 F.  During the summer, we use tinder, but in the winter, we just transfer embers from the woodstove inside.  Some nights, we need neither, as the fire restarts from yesterday's sparks and today's fuel.  After a few weeks, we stopped using birch (which we favor for fires inside the cabin) and instead, cut down some dead or dying black spruce trees in our woods. These trees are not long lived, so their trunks are slim enough we do not even need to split them, and they are famous/infamous for burning like torches.  A great use of standing dead fire hazards in the woods.

Obviously warming a newly filled bath in winter takes more than twice as long and about three times as much wood.  However, to our delight, the tarped tub retained most of the warmth, dropping only to the mid 80's F overnight, even at -4 F.  I haven't yet attempted  baths below that threshhold, but I believe that for much of our six month winter, I can enjoy the treat of a balmy bath before sunset, after a brisk afternoon walk in the woods.

In the summer, we drain the bath (30 minutes) into the sloping yard after three uses. In winter,  we retain the water for as long as three weeks, (by which point my husband says it smells like a sauna in a men's gym), because winter drainage is a bit worrisome.  I don't want an ice rink around the tub, so we wait until  a chinook wind raises temperatures for a day or so.  Another advantage we have discovered is that, so far, we have found it easier, and probably more energy cost effective, to heat up the hot tub rather than use the propane heater and electric power (generator when solar and wind produce little in winter) to run the shower and washing machine.

So, yesterday I took two net bags of laundry into the tub with me.  What a "red-neck" thing to do!  I also carried a book and a glass of sauvignon blanc.  Behind me, a Pandora channel cooed wooden flute music.  Ahhhhh.   I sank up to my neck, ignoring my book in favor of the pretty view of snow coated branches on the trees in my yard.   Not a bird moved.  As the laundry bobbed to the surface, I chuckled at the contrast of the lazy laundry, the remote nature setting, and the citified accoutrements of relaxation.  A red letter moment for me.

As I wring out the laundry on a line strung upstairs in our cabin, I realize that it smells like cedar.  My hair, too.  I like it.  Tomorrow, I look forward to another late afternoon dip ... with socks and maybe a pinot grigio.


  1. Definitely impressive. How long do you have to wait for a chinook wind, or are they fairly regular occurrences

    1. Some records indicate that they are occuring more frequently in recent decades. We have experienced a few unusual rains in December and January, sometimes preceded by the strong southern wind (a Chinook). Right now, much of Alaska is warmer than much of the Lower 48 states.

  2. I am impressed. The hot tub is beautiful!! what a wonderful addition to your homestead.

  3. I found the story of doing the laundry with a glas of wine a hoot. Country life is so different from the big city.