Herb : This a very useful contribution for me . I had a few points needing clarification which i inserted in your text. When/if you have time, would you clarify? For a long time, i've dreamed of using 4 stackable 10' -high silos on grade as the base for a house, capped with a peakless pyramid roof cavity . A round cistern in the centre (s) seems workable. I guess there may be more friendly internal coatings available now? than bitumins. What region are you in? Thanks for your experience!.......manfred ----- Original Message ----- From: "Merla" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, March 06, 2002 11:49 PM Subject: Drought/Cistern
> > Robert: > > Twenty odd years ago, I had occasion to build a 10,000 gallon cistern > using slipform concrete construction with forms from a Ken Kern Owner > Builder Book, I can't remember which one. The form was made with two > 1/8" x 4' x 3' strips set up with conduit and bolt spacers for a 3" wall MP: What were the interval distances between the spacers? > thickness. It could be used either for straight walls or circular walls > > by changing 3/4" plywood templates tabbed to the outside of the steel > strips. Mine was for an 8 ft radius. MP: So, the plywood's 8' radius curvature is fastened (how?) on the horizontal plane? ...on one or both sides of the steel? > > On the cleared site, I dug a post hole in the middle filled with > concrete and a pipe nipple to take a 10 ft high center pivot post 1 1/4 > inches--anything like that, size not important. A pivot arm 8 ft long > with a T is slipped over the center post and pivoted on it and a plywood > > washer and clamp to support the T, a union on the outer end that mated > with a union on the leading edge of the slipform. MP: How was the union attached to the slipform?...via a pipe nipple through both sides of the 1/8 th steel?. and at what height of the 3' or 4' steel sides ? > > Drop a 1/4 mile coil of barbed wire down the center pivot post, resting > on a plywood disc sitting on top of the T so the barbed wire could be > dispensed simply by pulling on it. The center pivot post was guyed from > > its top to trees outside the building area. A trench was cut for a > grade beam footing 10 inches wide, steel reinforced and 16" in diameter, MP: I assume you mean this prior to the slipform wall. Did you also use the pivot to mark out the beam trench? > with J-bolts protruding from it. A mortar cart was used to mix a very > stiff mortar (a motor-driven mixer will not work). You want a dry mix > you can handpack into the slipform that will stand by itself with the > slipform is moved ahead. MP: If i understand correctly you only pack 4" increments at a time. So, why do you need 3-4' high forms? The barbed wire is fed in a single strand into > > the center of the slipform and buried in 4" of mortar. There is no > vertical reinforcing in the wall. One 4" lift today is stacked on the > previous day's ring. The form rests on galvanized mortar tabs that keep > > the form from slipping down the wall. > > When I got up 8 feet, I plastered a rich cement mix on the whole inside > wall and then installed a drain outlet in the center leading to the pump > > from the bottom of a stainless steel salad bowl for a sediment trap with > > a foot valve screen for a filter in the line. Then a gravel pad was put > > down 3-4" thick, black plastic, then 6" wire mesh for slab reinforcement > > and a 4-6" concrete slab draining towards the collection bowl. > > The inside was finished off with multiple coats of emulsified asphalt > foundation coating. Log joists in a timber deck finished the structure > that became the center ring of a 40 ft diameter round house foundation. > The 3" concrete wall supported about a third the weight of the whole > house and never gave any trouble in the next twenty years. House air > was drawn in over the cistern water and the humidity was very welcome in > > a wood-heated house. When Ken Kern was told about this, he was horified, > > but 24 years later it's still in good shape. The house structure came > in at $6/sq ft built to code, including the cistern which had about $500 > > worth of materials in the cistern. 10,000 gallons of water in the > basement is a great thermal flywheel when you leave a wood heated house > for a couple of days in the wintertime. Even after a week of zero > degree weather with no fire, there was no ice build-up on the cistern. > > Signed, Herb > Merla's husband >
