Flood Vents
Photo Credit: FEMA Techinical Bulletin 1 - Openings in Foundation Walls and Wall Enclosures

Flood Openings protect residential houses and commercial buildings in floodplains by preventing hydrostatic pressure buildup that can destroy walls and foundations.

This site serves as a technical resource for examining the purpose of flood openings, how they perform, and when they are required. Floodvent.com will also define the different types, what is compliant, their effectiveness in sustaining a structure, demonstrate how they work, and reveal their importance in securing a low flood insurance premium.


A Foundation Flood Vent:

• Relieves (rather than resists) hydrostatic pressure on foundation walls during a flood event. The flood vent must allow for the automatic entry and exit of flood waters without human intervention

• Passively equalizes hydrostatic loads on enclosure walls below the BFE

• Must allow bi-directional relief of the flood waters regardless of the direction of flow

• Is a "wet floodproofing" technique

 

The National Flood Insurance Program (NFIP) Regulations and Building Codes require that any residential building constructed in Flood Zone Type A have the lowest floor, including basements, elevated to or above the Base Flood Elevation (BFE). Enclosed areas (enclosures) are permitted under elevated buildings provided that they meet certain use restrictions and construction requirements such as the installation of flood vents to allow for the automatic entry and exit of flood waters. This wet floodproofing technique is required for residential buildings. Commercial buildings have the option to wet floodproof, which can be more cost-effective compared to dry floodproofing.

 

 

FEMA Technical Bulletin 1
FEMA's Technical Bulletin 1 (TB-1) provides guidance on the NFIP regulations concerning requirements for openings in below BFE foundation walls, and walls of enclosures for buildings located in Flood Zones A, AE, A1-A30, AR, AO, and AH.
Non-Engineered Opening Guide
Downloadable reference to assist in the measurement and documentation of Non-Engineered flood openings for the Elevation Certificate in accordance with the National Flood Insurance Program.
Determine Your Flood Risk
Upload your Elevation Certificate for an evaluation by a Certified Floodplain Manager and receive a F.R.E. Flood Risk Report detailing your current situation and which mitigation solutions are best suited to reduce your flood insurance premium.