Flooding considerations for walls and floors


MAPEI Product Support

 August 30, 2017. 10:16 PM

Flood damage can be costly to repair and confusing to assess. We have prepared some information about how inland flooding (rising water from local rivers and streams and overflows from nearby ponds, lakes and reservoirs) can impact floors and walls in your home or business. MAPEI suggests involving your insurer and consulting professionals in helping to remediate flood damaged floors and walls.

What problems do flood waters cause to my floors and walls? 
Inland flood water will likely contain high levels of contaminants which can contribute to the rapid deterioration of certain building materials.  It is essential to start the drying process following industry accepted practices as soon as physically possible to prevent additional deterioration due to long term water exposure. Visible effects after flooding can include water stains, damage to gypsum backer boards (drywall), swelling of hardwood floors, swelling and degradation of engineered wood floors, and loosening of any layers (glues, membranes, primers, mastics, etc.) not designed for immersion. If not dried properly, or left untreated, moisture issues can lead to permanent damage to the wall or floor installation.  One of the primary concerns for flooded buildings is microbial growth.  Other impacts can include delamination of plywood and OSB, deterioration of cement backer and gypsum boards, loosening of patching/leveling materials, degradation of membranes, dissolving of bonding materials, and staining or deterioration of grout.  

First Steps to Recovery – First, keep additional water from entering the building by addressing areas where water entered such as holes and doorways. The next steps may require you to contact a water restoration professional who will remove the excess water and take industry recommended steps to dry the area. A trained technician will use several, if not all, of the following to dry the area: air circulation, ventilation, heating, and dehumidification. Cleaning and drying can restore many finished surfaces to good condition requiring no further action.  Other surfaces will have to be completely removed and replaced. The potential of a flooring material to be restored depends partly on its resistance to water and moisture. For more information about water damage visit the IICRC’s webpage on Safe Flood Clean-up Tips. It is important to note that in order for subfloors to be properly cleaned and restored, the flooring itself will likely require removal.

Precautions to Prevent Mold - After drying thoroughly, the second most important step is to determine if mold remediation will be required. A consultation with a mold remediation contractor and an inspection with an IEP (indoor environmental professional) are good starting points. For more information about mold visit the IICRC’s webpage on 5 Principles of Mold Remediation

Repairs – Check for loosely bonded tiles, flooring or other finishes by observation for surface defects. For example a tile surface may sound hollow when tapped with a blunt object or exhibit a white residue on the grout called efflorescence. Sheet vinyl may be loose or bubbled, and wood flooring installations may be hollow or heaved up. If microbial growth (mold) is observed, all repairs should stop until a professional mold contractor can contain the area. Although concrete slabs are more resistant to water intrusion, they can take longer to dry. If you observe the concrete is still wet you may need to have the water restoration professional return to address the issue.   Wooden substrates may have shifted or swelled and will need to be addressed before new flooring or wall coverings can be applied. Restore your substrate to where it is structurally sound, flat, and ready to receive new coverings. Installing new vinyl or hardwood will likely require the use of patches or levelers.  New tile installations can benefit from water resistant cement boards or underlayments. In cases of severe flooding, a licensed professional engineer should be consulted to verify the integrity of the building structure prior to beginning repairs.

Let us help - Flood damage is a complicated repair. When you have completed your drying and assessment of the damage to your installation we at MAPEI would be happy to help with choosing products that will help you complete your restoration including waterproofing, adhesives, and associated products for your situation.  Contact us to discuss your situation.

As we go to publication with this scheduled blog post, Texas is recovering from the effects of Hurricane Harvey and Florida from Irma. We encourage you to join with MAPEI and our employees in donating to disaster recovery efforts for the historic flooding that has occurred.


MAPEI Product Support

MAPEI Product Support


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