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WATER PUMPS, TANKS, TESTS, WELLS, REPAIRS
WATER CONSERVATION MEASURES
WATER CONTAMINANT LEVELS
WATER FILTERS, HOME USE
WATER HAMMER NOISE DIAGNOSE & CURE
WATER ODORS, CAUSE CURE
WATER PUMP REPAIR GUIDE
WATER PRESSURE LOSS DIAGNOSIS & REPAIR
WATER PUMP SHORT CYCLING
WATER SOFTENERS & CONDITIONERS
WATER TANK REPAIR PROCEDURES
WATER TANK: USES, TROUBLESHOOTING
WATER TESTS, CONTAMINANTS, TREATMENT
WATER TREATMENT EQUIPMENT CHOICES
WELLS CISTERNS & SPRINGS
WELL CHLORINATION & DISINFECTION
WELL FLOW RATE
WELL WATER PRESSURE DIAGNOSIS
WELL YIELD IMPROVEMENT
WINTERIZE A BUILDING
Rooftop & tower-mounted water storage tanks: this article describes rooftop water tanks and cisterns and tower-mounted water storage tanks, where they are used, how they work, and the use of booster pumps to improve water pressure in buildings with rooftop water storage tanks.
We include water tower design considerations, codes and standard references & citations. We also discuss using a booster pump to improve building water pressure in buildings with weak municipal water pressure or a weak rooftop
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Rooftop water storage tanks In some areas, Mexico, for example in our photo (above-left), rooftop water reservoirs are supplied intermittently with water from a water main in the street.
[Click to enlarge any image]
The rooftop water storage tanks in this photograph from San Miguel de Allende in Guanajuato are being used both to accumulate a water reservoir so that water is always available to the building, and to supply water at a useful pressure.
Our page top photograph of large rooftop water storage tanks was taken in Manhattan.
Rooftop storage tanks atop tall buildings have been in use for hundreds of years - the water tank shown at page top was constructed of wood with iron bindings and is used to provide good water pressure to fixtures in the multi-story building it serves. In our photos below we illustrate both single and multiple rooftop water storage tank installations observed in Manhattan and in Brooklyn, NY
. In New York City elevated water towers such as those shown below have been in use since the late 1800's. - The New York Times (2014).
See additional water storage tank details at CISTERNS.
Elevated tower-supported water storage tanks are used both to store water and to provide water at pressure to individual buildings, building sites, or entire communities, as we illustrate in the photographs below.
At left is a sketch showing a traditional water storage tank on a tower connected to and located adjacent to a water well.
[Click to enlarge any image]
Below we illustrate water storage towers of several shapes and types and found in several locations and countries including from left to right: Brunswick Georgia, U.S., The Taboada Hot Springs, Guanajuato, Mexico, and in the City of Buenos Aires, Argentina. Photos © Daniel Friedman.
Below we illustrate a horizontal cylindrical water storage tank at a damp in Dutchess County, New York in the U.S.
Water storage tank & tank tower or support construction need to confront
Water Tank & Water Tower Construction Standards & References
Reader Herman Voegel has pointed out that an up-and-coming area of storage containers includes spun-plastic tanks.
The plastic water tank in our photo (left) is used on ground level or on rooftops.
See details at PLASTIC CONTAINERS, TANKS, TYPES for details about using plastic tanks or containers for water storage.
General HDPE containers come in all shapes and sizes and are quite rugged and relatively cheap compared to using typical 12-gauge steel home heating oil tanks.
The ruggedness of HDPE plastic containers comes from their material density which is typically at a minimum specific-gravity of 1.7, and for heavy-duty at 1.9.
These tanks may be used for storing certain liquids besides water. But home heating oil has not yet been approved for storage in HDPE tanks, basically for two reasons:
However, fixes have been put in place to properly address these problems. UV-light is checked by using special color additives that prevent their light from penetrating and degrading the plastic walls. Permeation or seepage of oil through container walls is checked by coating them with fiberglass.
Unfortunately, even with these fixes, HDPE plastics for heating oil storage have yet to be universally approved and accepted.
Readers should also see PLASTIC CONTAINERS, TANKS, TYPES where we describe health and other concerns involving plastic tanks and other containers used for water storage.
Attic Water Storage Tanks or Attic Cisterns
Attic Cisterns or water tanks are installed in some buildings to perform the same function as rooftop-mounted water tanks.
Other smaller attic containers that look like a water reservoir may have been just an expansion tank for the heating boiler system.
Cisterns in basements or attics are an open-type water storage reservoir found indoors, and are discussed further at CISTERNS.
A cistern was generally placed where it could be fed by gravity from roof or surface runoff, but any indoor open topped reservoir of water could be called a cistern.
See SOLAR WATER HEATER ANTIQUE for another example of an attic water storage tank.
Water storage may not be on the rooftop nor in the attic. Cisterns or other water storage containers are often located in the basement or courtyard of buildings where they collect rainwater for future use. In the U.S. cisterns were often located in the basement of a (pre-1900) home. See details at CISTERNS.
In a seasonally damp climate such as New York, an in-use basement cistern would certainly be a likely source of unwanted building moisture and would thus be a risk for problematic mold growth.
In arid areas such as the U.S. Southwest and parts of Mexico, very large cisterns are often placed in a courtyard where they collect rainwater for use during the dry season.
The above-ground water cistern storage tank shown in our photo (left) is located in Mexico and is discussed at PASSIVE SOLAR HOME, LOW COST.
Rainwater for this cistern is collected from a near-flat rooftop and channeled to a large fiberglass holding tank - the blue tank in our photograph, (above left).
Piping also permits directing water into this tank from a well-fed cistern located atop the concrete block tower).
The tower's height provides water pressure to the building. Currently water is taken out of the bottom of this tank by a simple tank drain valve and hose attachment; to supply this water upwards to the building plumbing fixtures or perhaps to the cistern, a small electric pump will be installed.
See rainwater collection and storage cistern details at CISTERNS.
On low buildings or where the water tank is not high above the point of use some systems install a water pressure booster pump and tank. A water pump (WATER PUMPS, TANKS, DIAGNOSTICS) and probably a water pressure tank (WATER TANK BLADDERS & CAPTIVE AIR) will certainly be needed for ground-level or below-ground-level water storage cisterns.
Water pressure booster pumps and tanks may be installed in buildings where municipal water is supplied,
located on rooftops or anywhere in a building, so
don't assume that just because you see a pump and tank that the building is served
by a private well.
See WATER PRESSURE LOSS DIAGNOSIS & REPAIR for details on how to correct low water pressure in a building.
We discuss water pressure booster pump and tank systems in detail at PUMP, WATER PRESSURE BOOSTING
Readers of this document should also see WATER PUMP REPAIR GUIDE an specific case which offers an example of diagnosis of loss of water pressure, loss of water, and analyzes the actual repair cost and see Wells, Cisterns, & Springs for a discussion of types of drinking water sources and what goes wrong with water supplies.
If you're looking for information on types of septic tanks see our Septic System Design which includes articles about various types of septic tanks, steel, concrete, plastic, etc. The illustration at page top is courtesy of Carson Dunlop, Inc. in Toronto.
Continue reading at CHECK VALVES, WATER SUPPLY or select a topic from the More Reading links shown below.
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Frequently Asked Questions (FAQs)
I have a gravity water tank roof top on my house-Water is pumped up by the city when working ok-When the water (municipal) is not working I use the roof tank,
Generally what I do is shut the valve off at the street, then open the valve on the rooftop tank and it gravity feeds down into house.
The tank is located rooftop has 1 line going into the top of the tank for the inlet of water into the tank, the other lines is at the bottom that the water go's into the house..
Where would the check valve be located at? Best place to install it?
Will it interfere with the pressure if the water is only gravity with no pump?
James C. 6/27/2014
I'd put the check valve on the tank side of the shutoff controlling water coming from the street main. In that location the check valve will not be between the tank serving as the buildng water source and the fixtures and piping that the tank serves.
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