What Takes Place During The Home Elevation Process

One of the most common retrofitting methods is elevating a home to a required or desired height to prevent flooding in a home. When a home is properly elevated, the base floor will meet the Flood Protection Elevation requirement or recommendation for the location. This protects the living area from the most severe floods. There are several elevation techniques available to achieve the height necessary to protect the base floor of your home. Generally, elevating a home requires lifting the house and building a new foundation, extending an existing foundation below it, leaving the house in place, building an elevated floor within the house, or adding a new upper story.

Most frame, masonry veneer, and masonry homes are lifted and separated from their foundations during the home elevation process. They are raised on hydraulic jacks and held by a temporary support system while a new or extended foundation is constructed below. As a result, the living area is raised above the recommended or required home elevation level, which leaves only the foundation to be exposed to future flooding. This technique works well for homes initially built on a basement, crawlspace, and open foundations. When homes are elevated with this technique, the new or extended foundation can consist of either continuous walls or separate piers, posts, columns, or pilings. Masonry homes are more difficult to lift. This is primarily due to the homes' design, construction, and weight, but lifting these homes is not impossible. Depending on your location, you might find numerous contractors and home elevation companies that regularly elevate masonry homes.

There are multiple techniques that can be used to elevate masonry homes, and a variation of the technique above is used to elevate the home for frame, masonry veneer, and masonry houses on slab-on-grade foundations. In these homes, the slab forms the floor of the house and is either all or a significant part of the foundation. It is easier to elevate these homes if the house is elevated with the slab. After the slab and home are both lifted, a new foundation is constructed below the slab. Some homeowners find it easier to use one of two alternative elevation techniques, in which the house is left on its original foundation.

One technique is to remove the roof, lift the walls of the house, replace the roof, and then build a new elevated living surface. Another technique is to leave the current level with the slab floor and move the living space to an existing or newly constructed elevated living area. The then abandoned original living area is then used for parking, storage, or another access area to the home. These techniques are appropriate for masonry construction, which is naturally flood-resistant, but not for frame construction, which floodwaters could easily damage.

When elevating your home, one thing you should consider is the amount of elevation required by the Flood Protection Elevation. If your FPE is equal to the Base Flood Elevation (BFE), you will need to elevate your home so that the lowest floor is at or above that elevation. If your home has substantial damage or is going through significant restoration, this is a requirement. If that doesn't apply, you may be able to elevate your home to any height you wish, although raising your home above the BFE provides the best protection for your home and could decrease the flood insurance rate. Regardless of whether your home has substantial damage or not, you should consider elevating your home at least one foot above the BFE to protect it from flooding. This could be as little as three or four feet above the existing ground level, depending on your location. This usually has minimal effect on your home's appearance and wouldn't require a lot of landscaping or regrading. Suppose you are looking into elevating your home more than four feet above the current level. In that case, you should consider elevating your home a whole story so that you can use that space below the elevated living space for parking, storage, or another accessible room for your home.

The elevation process is the same for the frame, masonry veneer, and masonry homes on basement and crawl space foundations. The first step of the process is for holes to be made at intervals in the foundation wall so that a series of steel beams can be installed below the home's foundation or elevated surface at critical points. The lifting contractor can remove the individual blocks if the foundation walls consist of concrete blocks to create the required holes. If the walls are poured concrete, the holes will be cut out. The second set of beams are then placed below the first set. The two sets of beams extend the width and length of the house and form a cradle that supports the house as it is being raised.

The contractor must first dig trenches at intervals around the foundation to lift a home. Next, the beams are lowered into the trenches and inserted below the floor framing. The contractor may also dig holes for the lifting jacks. The number of jacks needed will depend on the size, shape, and type of home that is being elevated. Once the beams and jacks are installed, the elevation process will begin. During the process, the jacks will begin elevating the home in intervals; the homes and jacks are supported on cribbing while the jacks are raised. After the home is elevated high enough to add a new foundation or build onto the existing one, it is supported by cribbing again.

In contrast, the foundation walls are extended to the desired height with concrete blocks or poured concrete. The home is then lowered onto the extended foundation, the beams are removed, and the holes are backfilled. One crucial part of the project is installing openings in the foundation walls no higher than one foot above the ground so that floodwaters can enter and equalize the internal and external hydrostatic pressure.

If you are elevating your home with substantial damage or significant restoration, your community floodplain management ordinance may not allow you to have a basement. The NFIP regulations define a basement as "any area of the building having its floor subgrade on all sides." Therefore, if your home has a basement, you will be required to file it as a part of any elevation project.