Through changing weather patterns and the increased prevalence of extreme weather events such as hurricanes, flood waters are becoming a major concern for homeowners and building owners. While flooding traditionally occurs around coastal areas and regions prone to hurricanes, it is not unusual to see major flooding occur in inland areas like that experienced in South Carolina in 2016 and the seasonal spring floods in the Canadian Prairie Provinces, Manitoba and Saskatchewan. According to figures released by FEMA, flooding accounts for more than $3.5 billion in insurance claims annually.
Flood waters due to storm surge, underperforming drainage or broken levees can:
- Induce physical deterioration of the building structure
- Perpetuate mold growth
- Contain contaminants , corrosive dissolved salts and/or raw sewage
- Saturate insulation and wallboard, carpets and furniture
- Contribute towards respiratory problems, allergies, infection and irritation (eyes, skin)
Can you mitigate flood damage with specific building materials?
Flooding and the resulting flood damage, while it is not completely preventable, can be mitigated through the use of flood-resistant building materials. As noted in previous posts, the Federal Emergency Management Agency (FEMA) has identified a number of flood-resistant building materials that are ideal for use including corrosion resistant coated steel, pressure-treated wood, epoxy formed-in-place flooring as well as closed-cell spray foam insulation. These products fall into Class 4 or Class 5 of FEMA’s flood damage-resistance classification system. The classification system determines a material’s suitability and acceptability for use in below the base flood elevation. Building materials that fall into Classes 1-3 are deemed unacceptable as flood-resistant materials.
When it comes to flooding, spray foam insulation that is closed-cell is regarded as a Class 5 building material by FEMA. According to FEMA, as a Class 5 material, closed-cell spray foam insulation can be used as a finished material in walls, floors and ceilings. Spray foam insulation products such as Icynene ProSeal and Icynene ProSeal LE are ideal for use in regions prone to flooding due to their ability to reject bulk water ingress and provide additional structural support to the building assembly. Other insulation types such as fiberglass, mineral wool and blown-in insulation are regarded by FEMA as Class 3 materials while open-cell spray foam insulation and cellulose insulation are deemed Class 2 materials, making them unsuitable. That said, open-cell spray foam insulation can help play a role in other areas of the structure to address thermal insulating, moisture management and mitigating the risk of wind uplift.
Closed-cell spray foam insulation in flood prone areas
Closed-cell spray foam insulation used in flood prone areas can be used as a water resistant barrier to deflect bulk moisture away, particularly wind driven rain. Furthermore, closed-cell spray foam insulation tends to have very low water absorption (less than 1%) and as mentioned earlier, can provide additional ‘racking’ strength to help resist the high winds of a storm or hurricane.
For many homeowners, materials such as closed cell spray foam insulation, like Icynene ProSeal or Icynene ProSeal LE, offer a durable and robust solution to helping mitigate the damage potential stemming from extreme weather events such as hurricanes, storm surges and floods. Architects can seek to include flood-resistant materials in their design specifications as an effective solution for those living in such high risk areas.