Components – Flood Flaps FEMA Accepted Foundation Flood Vents:
The Flood Flaps – Flood Vent Box:
The vent box portion preferably includes at least one and preferably two wall flap channels carved into the inside faces of the two opposite side wall portions, and the bottom box portion between them, in the area of the box rear end. The term “side flap edges” herein is meant to include the side edges and the bottom edge of the Flood Flap. The side flap edges of each Flood Flap fit into the opposite side sections of the corresponding flap channel. The bottom flap edge of the Flood Flap fits into the central section of the flap channel. The side sections of the flap channel are continuous with the central section of that flap channel. The three free edges, of the outer Flood Flap a fit into the outermost flap channel, and the three free edges, of the inner Flood Flap fit into the innermost flap channel. By “free” is meant that the edges are not attached to any structure, which permits the Flood Flap to flap in and out with water entering or exiting the Flood Flaps vent during, for example, a flood.
The vent box portion is comprised of two generally parallel side wall portions connected at their bottom edges to opposite edges of a bottom box portion, and along their top edges to the opposite edges of a top box portion. All of the four portions – are generally rectangular in shape. The vent box portion is preferably generally rectangular in cross-section. The vent box portion is preferably one-piece and made of any suitable material, such as plastic or polyvinyl chloride, most preferably molded recycled plastic The side wall portions are preferably same sized and parallel to one another, and at right angles to the top and bottom box portions,. The top and bottom box portions are preferably same-sized and parallel to one another and at right angles to the side wall portions. The outside corners of the vent box are preferably square, though they may be rounded.
Although its size may vary, the vent box is most preferably about inches deep, its size being determined by the size of a cinder block, since the Flood Flaps vent replaces one cinder block. The Flood Flaps vent is preferably (but not limited to) about 8 inches by inches by inches. A second size is about inches by inches by inches. In the case of a brick building wall, which is generally thinner than a cinder block wall, a rear part of the Flood Flaps vent simply sticks out into the crawlspace.
While the front end of the vent box is covered by the grate portion, the open rear end is covered by at least one, and preferably two or three, Flood Flaps. Without meaning to be bound by theory, it is believed that one Flood Flap is sufficient for use in temperate climates. In a majority of climates, two Flood Flaps covering the rear end of the box are optimal. Double Flood Flaps provide thermal insulation that is consistent with the insulation of the interior crawlspace walls. (Insulation is installed on the crawlspace walls as part of the sealing process.) Where winter or summer temps are consistently excessive (e.g. extreme northern climes, desert locales), three Flood Flaps, one behind and parallel to the next, are preferred for the additional insulation they provide. Three Flood Flaps help regulate the temperature in the sealed crawlspace and yet permit flood waters to pass through the crawlspace in the event of a flood.
The Flood Flap:
Each Flood Flap extends down substantially vertically from the top box portion of the vent box. Where the Flood Flaps vent has two Flood Flaps, the top box portion includes two parallel flap slots that extend almost from one side edge to almost the opposite side edge of the top box portion over the otherwise open rear end of the vent box. The flap slots are preferably rectangular-shaped (looking down from above), with short side edges. The rearmost slot a is preferably about an inch or two from the rear end of the Flood Flaps vent for strength.
Each Flood Flap preferably includes a thickened upper flap wedge that extends along the top of each Flood Flap. The upper flap wedge is preferably generally triangular in cross-section. To assemble the Flood Flaps vent, the body of each Flood Flap slides down through the flap slot. The flap slot is also generally triangular, or wedge-shaped, in cross-section, so that the flap wedge catches in the flap slot. Thus, the Flood Flap hangs in the flap slot, suspended by the flap wedge in the flap slot. The Flood Flap need not be glued into place within the Flood Flaps vent.
The Flood Flap is the about the same size as the passageway at the rear end of the vent box. The other three side edges, of the generally rectangular-shaped Flood Flap are preferably sharp-edged. The three free edges, of the Flood Flap preferably contact the inside of the vent box. The Flood Flaps are preferably the exact size of the rear end opening so as to prevent air from passing through from the vent passageway into the crawlspace.
The Flood Flaps – Flap Channel:
The flood flap channel helps maintain a home position for the free edge, of the Flood Flap that fits into the flap channel, protecting the Flood Flap from windy conditions. Even though its three flap edges, rest in the flap channel, the flexible Flood Flap is capable of swinging from the top flap edge, which is preferably a flap wedge, in the vent passageway. The base of the flap channel is preferably curved in order to facilitate movement of the Flood Flap edges, into and out of the flap channel. The base of the flap channel is less preferably substantially flat with relatively straight sides parallel to one another bordering the channel base. The free flap edges, in the flap channels help seal the rear vent opening.
The Flood Flaps – Flood Vent Materials:
The Flood Flaps flood vents are made of a durable material, such as rubber or vinyl sponge, that is flexible enough to resist air flow, thick enough to provide insulation, and strong enough to keep rodents and other vermin out, yet allow water flow under flood conditions. The Flood Flap vent material is preferably a molded, spongy material with a non-porous, semi-rigid skin sealed to the spongy material. It may be buoyant so that the body of the Flood Flap is easily pushed upward by flood waters. Air bubbles are preferably entrained (suspended) in the Flood Flaps for buoyancy. If a Flood Flaps vent is already in a crawlspace wall, the material is flexible enough to permit a Flood Flap to be replaced from inside a vent box, if necessary on rare occasions. To do so, the upper flap wedge at the top of the Flood Flap is squeezed, inserted into the flap slot, and released. The three side edges, of the body of the Flood Flap find a home in the corresponding flap channel, which is next to and below them. When the Flood Flaps vents are in the substantially vertical, resting position (steady state), the side edges, of the body of the Flood Flap are seated in the corresponding flap channel.
The Flood Flap foundation vent material is flexible enough to be moved in either direction by slight water pressure. The sturdy Flood Flaps are sufficiently flexible to return to their vertical, “sealed”, resting, home position, and dry out once the flood subsides. The Flood Flaps flood vents are useful for those buildings in flood plains or other locations exposed to the possibility of high water (e.g. during hurricanes, dam breaks), such as buildings by rivers, creeks, lakes, the ocean, or downstream from dams. The length and height of the Flood Flap crawl space vent is approximately the length and height of the vent passageway interior.
Flood Flaps – Flood Vent Design:
Although the thickness of the Flood Flaps flood protection vents may vary, it has been found herein that a preferred thickness of between about ¼ and ½ inch is optimal for providing insulation. In their vertical, at rest positions, the inner Flood Flap is not in contact with the outer Flood Flap. Importantly, the Flood Flaps are preferably between about ½ inch and about two inches (most preferably about an inch) apart so the air space between them provides additional insulation. The insulating Flood Flaps help to seal the crawlspace. The width of the flap wall channel is preferably about twice the thickness of the Flood Flap in order to help the Flood Flap slide into home (resting) position in the wall channel.
Alternatively and less preferably, the upper edge of the Flood Flap is attached within its flap slot in the top box portion. The upper flap edge is less preferably squared in a conventional manner, or sharp-edged like the other three, unattached flap edges, as described herein. To insert the upper flap edge in the flap slot when the Flood Flaps vent is being made, the upper flap edge is squeezed, inserted into the flap slot, and released. Since it is made of a foam-like material, the upper flap edge expands back out again once it is inserted, which holds it in the flap slot. This is another advantage of the Flood Flap being made of sponge vinyl or the like. Once it is in the flap slot, the upper edge of the Flood Flap may be attached in the slot, as by gluing.
The three (free) edges, of the Flood Flap are less preferably substantially squared off, or flat. They preferably have a sharp, tapered edge shape, though, for optimal functioning. The unattached edges preferably have the same shape/appearance as one another, and one of six alternate shapes. Moving down from the upper left of the free edge or is: rounded, with the round at the center of the edge; knife-edged (preferred); or pointed. Moving down from the upper right of the free edge or can be an off-center rounded edge (most preferred); an off center knife edge; or a blade edge. It has been found herein that these sharper edges – glide more easily into and out of the flap channel, permitting the flaps to quickly find the home (at rest) position and helping to seal the Flood Flaps, FEMA accepted flood vents.
Contact Flood Flaps today at 843-881-0190 or [email protected] to find out how our flood vents can help reduce your flood insurance, and protect your home or business property from flood damage.