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Protecting Your Home > Dry Floodproofing
Dry floodproofing is appropriate for shallow, short duration flooding. Longer term flooding is likely to leak through the structure.

This method has three components:

  1. Make the walls of the structure watertight. This is easiest for masonry or brick faced walls which can be covered with a sealant. Wood, vinyl, or metal siding needs plastic sheeting to make them water tight. The most effective approach is to apply a sealant, apply plastic sheeting and then cover the job with brick facing to protect the water proofing from punctures.
  2. Provide closures for openings, including doors, windows, dryer vents, and weep holes.
  3. Account for sewer backup and other sources of water entering the building. For shallow flooding, this can be done with a floor drain plug; although a valve system is more secure.

Shortcomings:

  • Requires human intervention, someone must be available to close doors and other openings.
  • Success depends on the structure's condition. Will not work effectively if the slab is cracked.
  • Periodic maintenance is required to check for material decomposition.
  • NFIP will not offer a lower insurance rate for dry floodproofed residences.

Cost can vary according to the house's size, construction, and condition; and can range from $5,000 to $20,000 depending on how secure the owner wants the structure to be. An experienced contractor provides greatest security.

 

The dry floodproofing on the above house is barely visible

The same house has a removable barrier to block water entering through the opening for the door

For more information, see: