Five Flood-Resistant Building Materials

According to the Federal Emergency Man­age­ment Agency (FEMA), there have been at least 26 sig­nif­i­cant flood events that have impacted Texas in the past 40 years, not including the high number of flash and river floods. To help combat these disasters, Texas builders are following FEMA’s guidance by creating flood-resistant struc­tures whenever possible.

FEMA has issued a rec­om­men­da­tion to build with flood damage resistant materials to minimize the time-consuming and costly process of rebuild­ing after flood damage. Building materials are con­sid­ered flood-resistant if they can withstand direct contact with flood waters for at least 72 hours without being sig­nif­i­cant­ly damaged.

Recommended Flood-Resistant Building Materials

These five flood-resistant inno­v­a­tive building materials are rec­om­mend­ed by The Asso­ci­a­tion of State Flood­plain Managers to protect your next project and the people who live or work there.

1. Naturally Decay-Resistant Lumber

Photo: Windsor Plywood

The most common building material is, of course, lumber. While you may think wood and water don’t mix, there are actually several types of wood that are naturally resistant to decay.

For instance, western red cedar and redwood are naturally decay-resistant. Both types of wood, however, can split when driving fasteners into the wood. Also, both can bleed tannins that appear as stains around fasteners which can show through painted surfaces. To combat this, make sure to follow proper prepping pro­ce­dures to ensure the wood will accept wood stains and clear finishes.

Cypress is another decay-resistant option that grows in swamps and accepts stains and clear finishes.

White oak is much less porous, decay-resistant and very strong. However, it does split easily like redwood and cedar, so you should predrill screw holes for fasteners.

Com­pos­ites offer another option if you want the look of wood without the splin­ter­ing issues wood can bring. Made from ther­mo­plas­tic resins, wood flour and wood fiber, com­pos­ites have no defects and do not compress like wood. It also doesn’t warp, crack or rot. Although com­pos­ites come in a variety of colors, composite wood doesn’t absorb paint and stain, so it can’t be as cus­tomized as wood.

2. Marine-Grade Plywood

Photo: J. Gibson McIlvain Company

Marine-grade plywood is hardwood plywood made with water­proof glue, which allows the wood to retain its integrity, so, if exposed to moisture, the glue won’t fail and the wood layers won’t fall apart.

Standard plywood products can be found at hardware stores, but even the best-rated plywood at a hardware store isn’t as high quality as marine-grade. Standard panels are generally made with thicker layers of softwood, which can create voids or holes in the center of the wood which is unde­tectable until you cut into the panel.

Marine plywood, on the other hand, is made from hardwoods. It’s created with thin layers of 100 percent hardwood to make it stronger, harder and with a finer grain. However, the wood itself is not naturally water­proof unlike the glue used to create it. When used in a flooding area, it must be protected by a strong water-resistant finish.

3. Closed-Cell Foam Insulation

Photo: Certain Teed

Spray foam insu­la­tion is commonly used to increase a home’s energy effi­cien­cy and maintain year-round comfort – all while offering quick appli­ca­tion and ease of use in hard to reach spots. However, not all spray foam is created equal.

Closed cell foam is denser and offers higher R‑values than other types of foam — around 6.0 per inch, although some higher per­form­ing for­mu­la­tions have R‑values of 7.14 per inch and higher. Because of its increased resis­tance, closed cell foams feature better insu­la­tion and are more resistant to water degra­da­tion or penetration.

4. Metal Roofing

Photo: Drexel Metals, Inc

Heavy rains are often accom­pa­nied by strong winds. Water pen­e­tra­tion through or around otherwise intact openings from wind-driven rain can do a sig­nif­i­cant amount of physical damage, cause occupant dis­place­ment and business inter­rup­tions, and lead to extensive restora­tion expenses,” cautions Dean Lewis, American Archi­tec­tur­al Man­u­fac­tur­ers Asso­ci­a­tion. It can also create a mold-friendly envi­ron­ment in unseen wall cavities and in spaces between exterior sheathing and cladding.”

For­tu­nate­ly, according to Mark Henry, a senior research engineer at Butler Man­u­fac­tur­ing, wind-driven rain is usually not an issue for metal roof systems. They are designed to be weath­er­tight,” he says. The long inter­lock­ing roof panels do not provide a gap through which wind could drive rain into the building interior.”

5. Concrete

Photo: Bautex

What’s more solid than concrete? With a single material, we can accom­plish many things: energy effi­cien­cy, strength, dura­bil­i­ty, resilience, and safety,” explains Dr. Jeremy Gregory, the executive director of the Concrete Sus­tain­abil­i­ty Hub. Another benefit? Because of its chemical nature, concrete actually gets stronger over time, not weaker. There are four main types of concrete building systems used in the US:

Concrete Blocks: The tra­di­tion­al rec­tan­gu­lar blocks are the most widely used concrete building system as they provide an afford­able defense against hurricanes.

Removable Forms: Insu­la­tion and rein­forc­ing steel are placed inside removable wall forms, made of aluminum, wood or steel, before concrete is poured into the forms. Once the concrete has cured, the forms are removed, leaving concrete walls filled with insu­la­tion and steel. This makes them espe­cial­ly resistant to high winds, as well as flooding.

Panel Systems: There are two types of panel system: precast concrete and site-cast concrete. With precast, the walls are made off-site, filled with steel, insu­la­tion and elec­tri­cal wiring, before being moved to the project site and put into place with cranes. With site-cast concrete, the walls are created on site by pouring into a cast, but this method requires a very open area so the walls can be tilted into place once they are finished.

Insu­lat­ing Concrete Forms (ICFs): ICFs are building blocks made of foam plastic or EPS-cement composite (a mixture of cement and expanded poly­styrene) which makes a durable, energy efficient concrete block. The blocks are stacked and then filled with concrete. Some ICFs, such as Bautex Blocks, are FEMA rated against floods and hur­ri­canes, as well as being energy efficient and fire rated (four-hour).

When you work in areas that see sig­nif­i­cant flooding, such as Texas, you need to be able to create buildings that will be able to survive water damage.

To learn more about how the right building system can protect against floods, contact the experts at Bautex at [email protected]​bautexsystems.​com or sign up for updates on how Bautex Systems is trans­form­ing the built environment.