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OUR CUSTOMER’S QUESTIONS & OUR ANSWERS
The following are a list of questions from our customers and our answers to their questions. The answers are supported by information found on FEMA’s website, www.fema.gov, and FEMA’s publications. We have attached these references for your convenience. Look under the heading (Questions & Answers) on our home page and follow the dropdowns.
FEMA is the Federal Emergency Management Agency. FEMA’s mission is to support citizens and first responders to ensure that as a nation we work together to build, sustain, and improve a capability to prepare for, protect against, respond to, recover from, and mitigate all hazards.
NFIP is the National Federal Insurance Program. The NFIP is a Federal program enabling property owners in participating communities to purchase insurance protection against losses from flooding. This insurance is designed to provide an insurance alternative to disaster assistance to meet the escalating costs of repairing damage to buildings and their contents caused by floods.
TB 1 / August 2008 is a FEMA technical bulletin titled Openings in Foundation Walls and Walls of Enclosures – Below Elevated Buildings in Special Flood Hazard Areas in accordance with the NFIP. This technical bulletin explains NFIP’s foundation flood opening requirements. It also explains the NFIP’s requirements for guidance on non-engineered openings and engineered openings. This technical bulletin is attached.
A non-engineered opening is calculated by multiplying the height times the width of the flood vent’s opening. They are used to meet the NFIP’s prescriptive requirements of 1 square inch of net open area for every square foot of enclosed area.
Engineer openings have a characteristic that differ from non-engineered openings. They are designed and certified by a registered design professional as meeting certain performance characteristics described in FEMA TB 1 / August 2008. Engineered openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters. The advantage of an engineered flood vent compared to a non-engineered vent is it takes fewer engineered flood vents to meet NFIP’s requirements.
What is the NFIP Regulation that defines the flood vent requirements?
The NFIP Regulations for enclosures are codified in the Title 44 of the Code of Federal Regulations, in Section 60.3(c) (5), which states that a community shall: “Require, for all new construction and substantial improvements, that fully enclosed areas below the lowest floor that are usable solely for parking of vehicles, building access or storage in an area other than a basement and which are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or meet or exceed the following minimum criteria: A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided. The bottom of all openings shall be no higher than one foot above grade. Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.”
Yes. NFIP's flood insurance requirements boil down to this:
1 – You must have at least one square inch of opening in the foundation wall for every square foot of house’s enclosed area.
2 – The bottom of the flood vent opening must be less than 12 inches above the ground.
3 - Two vents per enclosed area, on different exterior walls.
Does a flood vent have to have a 3” opening so a tennis ball can pass through?
No. TB 1 / August 2008 defines the 3” opening size on page 26 as: “Engineered openings are to be not less than 3 inches in any direction in the plane of the wall. This requirement applies to the hole in the wall, excluding any screen, grate, grille, louvers or devices that may be placed in or over the opening.” Title 44 of the Code of Federal Regulations, in Section 60.3(c) (5), states: “Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.” The 3 inch rule is for the hole in the wall not the space between the louvers or screens.
Can I put a fixed cover on a flood vent in the winter?
No. TB 1 / August 2008 explains on page 19 that it is unacceptable to “have detachable solid covers that are intended to be manually installed over the opening in cold weather, because they do not allow for the automatic entry and exist of floodwaters when the cover is in place.”
Can screens or louvers be used over flood vents?
Yes. Title 44 of the Code of Federal Regulations, in Section 60.3(c) (5), states: “Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.”
Do flood vents have to be labeled with the opening size?
Not if the flood vent package is labeled with the opening size. TB 1 / August 2008, page 20 sates: “Manufacturers of devices intended for use as standard air vents typically indicate the number of square inches that each device provides for air flow (either stamped into the metal frame or noted on the packaging).
ICC stands for International Code Counsel. ES stands for Evaluation Service. ICC-ES evaluates building products for compliance with code. For more information about ICC visit their website at www.icc-es.org. Crawl Space Door Systems, Inc. is a member of ICC.
This is an ICC test that is used to prove that an automatic flood vent opens during a flood event. The title of ICC-ES (AC364) is “Acceptance Criteria for Automatic Foundation Flood Vents”. Some flood vents have an automatic lid that is closed when there is not a flood event and opens automatically when there is a flood vent.
No. ICC-ES (AC364) is a test to prove an automatic flood vent opens automatically to allow flood waters to enter and exist. This is a requirement for flood vents that automatically open and closes. Our vents stay in an open position all of the time and do not require this test. The criteria for this test is attached and titled “ICC-ES (AC364)”. Also, attached is an example of the evaluation report “ESR-2074” showing results of the test.
We built our flood vents out of a durable ABS plastic so they do not rust or rot and they do not have to be maintained. Metal flood vents need to be oiled and sprayed with a lubricant to keep them from rusting.
Why did you design your flood vents with fixed louvers?
We did not want any moving parts that could malfunction and stop the flow of water during a flood situation. We also wanted them to stay in the open position to allow fresh air to flow into and out of the crawlspace.
Why does your flood vent fit flush on the outside surface of the foundation wall?
We designed it to attach to the outside surface of the foundation wall for two main reasons; to make it easy to install with either construction adhesive or stainless screws and so you do not have to chisel or grind the brick.
WAREHOUSE:
Chris Qualtieri, Warehouse Mgr.
5741 Bayside Road #107
Virginia Beach, VA 23455
Ph: 757-274-9989 chris@crawlspacedoors.com
Call for service hours
William G. Sykes
President
Patent Attorney
Product Designer
Electrical Engineer
Inventor
Member of the ICC
Ph: 757-615-3613
Crawl Space
Door Systems, Inc.
3700 Shore Dr #101
Virginia Beach, VA 23455
Ph: 800.230.9598
Ph: 757.363.0005
BY APPOINTMENT ONLY
