How Do Rooftop Water Tanks Work? Why You May Still Need a Booster with Rooftop Water Storage

You can’t see a panoramic photo or aerial tour of New York City’s rooftops without noticing the thousands of water tanks above many buildings, particularly those built prior to World War II. If you’ve wondered, “How do rooftop water tanks work?” this post explains their function. We also review why sometimes booster pumps are needed even with rooftop water storage, so you understand more about how to achieve the perfect water pressure in your condo or co-op building.

How Do Rooftop Water Tanks Work?

Water storage explained

The invention of the elevator meant that New York City buildings could finally reach above six or seven stories – the limit most people would climb using stairs to their residence. But taller building heights came with a new problem: how to provide water for the upper stories. Supplying water to towers and skyscrapers involves pushing against the force of gravity.

Water circulator pumps can only do so much to counteract the natural gravitational force. In fact, for every foot that water moves upwards, it loses 0.434 psi. That means that the upper stories on super tall buildings have trouble getting any water at all. This isn’t just an issue of convenience. Low water pressure spells disaster for fire suppression systems like sprinklers.

To overcome this pressure issue, high buildings in New York City started adding water tanks to their rooftops. These tanks could store enormous amounts of water to be released over time as needed to upper floors, while the municipal water supply took care of lower stories directly. A pump station in the basement propels water to the roof for use later. As the tank empties, it triggers the pump to send more water from the city main to the roof.

You’ll observe that rooftop water tanks in New York City are only made of two materials according to the building code: steel and wood, with cedar wood being the preferred choice. It’s a natural insulator, keeping water cool in summer and preventing it from freezing in winter. The first builders of early rooftop tanks were coopers, immigrant barrel makers who learned their trade in Europe, and the current makers of wooden rooftop water containers in New York are descendants of those family businesses.

Although the materials and construction of rooftop tanks haven’t changed in over a century, new technology has been added to monitor water levels, temperatures, and the like. New York City requires annual tank inspections, as well as yearly draining and cleaning to prevent the growth of dangerous bacteria and other contaminants. This work must be done by licensed master plumbers with confined space training.

With proper maintenance, rooftop tanks can last decades. When they’re replaced, it’s done all in one day, like assembling a giant wine barrel, with no glue involved.

Some of the factors involved in installing rooftop water tanks include:

  • Making certain the roof can hold the weight of the tank and water
  • Securing the tank against natural elements, especially wind, which affect all rooftop equipment
  • Protecting the water supply against contaminants, animals, etc.
  • Allowing access for maintenance, inspection, and repair
  • Creating a conduit for overflow
  • Ensuring the basement pump system is sufficient for tank supply
  • Designing correct circulation from the tank to units

Why Do Rooftop Storage Tanks Still Often Require Booster Pumps?

Fighting gravity at upper levels

As mentioned above, a ground-level pump system is still needed with rooftop water tanks to supply them with water in the first place. These heavy-duty pumps are similar to the booster pumps we use in newer tall buildings that rely solely on the New York City municipal pipes. Booster pumps give extra “oomph” to water pressure, helping plumbing systems overcome the force of gravity to ensure equal water pressure on all floors and ensuring fire suppression systems have adequate water supply.

However, even with a rooftop water storage tank, you may need an additional booster pump or series of booster pumps plus the basement pump. Why? You still have to consider the force of gravity with rooftop tanks. Water wants to follow its natural flow downwards from these tanks, meaning lower floors may still wind up with higher water pressure than upper ones, especially the first few floors beneath the tank.

While simply having any water at all may have been enough for early NYC tall building dwellers, nowadays the demand for perfect water supply is more exacting, and fire codes have also become stricter, measuring precise sprinkler pressure during inspections.

When our experts at Antler Pumps work with clients in New York City tall buildings that use booster pumps, both with and without rooftop water tanks, we use a variety of factors to calculate and achieve ideal water pressure. These include peak demand loads, height of the building, pressure at the municipal supply, plumbing anatomy (e.g., presence of or ability to add risers), operational issues, and budget.

Sometimes we add pressure reduction valves at lower levels to eliminate high static pressure and excessive noise at taps. In newer buildings where space allows, we may suggest using multiple interior steel water storage tanks spaced at certain intervals, each with their own booster pumps, rather than a single rooftop tank. Each property has to have the water pressure system customized for its unique features.

Is your property experiencing water pressure problems? Whether you have a rooftop water tank or use only the municipal water supply direct from the main, you likely need the assistance of pumps to get that perfect pressure occupants crave. We welcome the opportunity to consult with you on your pressure issues. Call Antler Pumps today at 212-534-2500 to set up an appointment.


Our Privacy Policy

Omnia Mechanical Group(the “Company”) strives to ensure the highest standards for property listings and customer information privacy. Please review the following statement to learn about our company practices and policies. Please be aware that our Privacy Policy is subject to change at any time.

1. Purpose.

This Privacy Policy (“the Policy”) provides information on how the Company uses your personal information. By agreeing to the Policy, you agree to our collection and use of your personal information as described in the Policy. This Privacy Policy is effective for all new users of Sanitaryplumbing.com.

2. Personal Information.

You can browse some areas of omniagroup.nyc (“the Website”) without being a registered user. However, certain activities do require registration. (You consent to the transfer and storage of your information by registering with omniagroup.nyc).

3. Use of Information.

Our primary purpose in collecting personal information is to provide you with a safe and user-friendly experience. For example, the Company may use your personal information to:

  • Improve our services and the Website’s content and layout;
  • Provide the services and necessary customer support you request;
  • Resolve disputes, collect fees, and troubleshoot problems;
  • Track and record customer satisfaction with our services;
  • Protect the Company against error and fraud;
  • Inform you of special promotions and announcements;
  • Enforce our agreements, terms, conditions, and policies; and
  • As otherwise described to you at the time of collection.

We may occasionally ask you to complete optional surveys. These surveys are used to improve and customize your experience with Sanitaryplumbing.com.

The Company always provides you the ability to opt-out of further communication such as promotions and surveys; see the Opt-Out section below.

The Company does not share any of your personal information with outside organizations, companies, individuals, etc. The only exception to this standard is if such a disclosure is reasonably necessary to respond to any and all legal processes.

4. Links to Other Sites.

The Website may have links to other websites that may collect personally identifiable information about you. The Company is not responsible for the privacy practices of the content of those linked websites.

5. Safety & Security Precautions.

The Website has strict security measures in place to protect you and your information from fraud. Once your information is provided to Omnia Mechanical Group, we strive to ensure the confidentiality of your identity and information.

6. Opt-Out.

The Company provides you with the opportunity to opt-out of receiving promotional and other non-essential, marketing-related communications from Omnia Mechanical Group. If you would like to opt-out of these select communications, please see any of the Company’s email communications and follow the directions indicated.

7. Account Protection.

Your password ensures the security of your account. When choosing a password, the Company suggests using various characters. It is highly recommended that you do not disclose your Sanitaryplumbing.com password to anyone. (If you do disclose your password or your personal information with others, you are responsible for all actions taken in the name of your account.) If the security of your password is compromised for any reason, please contact the Company immediately.

8. Accuracy of Information

The Company does not guarantee the accuracy of information for any and all of its properties on the Website, and is not responsible for any errors or misrepresentations (made by Renters, the Client, or otherwise).

9. Cookies

The Company may place a small cookie on your computer’s hard drive. This allows us to personalize your use on the Website. In order to maximize the functionality and usability of the Website, you must set your browser’s preferences to allow both permanent and temporary cookies.

10. Changing Your Personal Information.

Should your personal information change, please immediately update your information on the Website. This will ensure the accuracy of our records. The Company does retain personal information from closed accounts in order to comply with law and collect and disburse any fees owed.

11. Third Parties

This Privacy Policy addresses only the use of information we collect from you. Since omniagroup.nyc does not control the privacy policies of third parties, you are subject to the privacy policies of those third parties. It is advisable that you consult with the management of third parties before you disclose your personal information to others.

12. General

We may amend this Privacy Policy at any time by posting the amended terms on the Website. All amended terms are immediately effective after they are initially posted on the Website.

13. Privacy Policy Questions & Concerns

Questions and/or concerns regarding the Policy should be emailed to the following email address: info@omniagroup.nyc.