Home Elevation Techniques - Which One is Right for You?

When deciding to elevate your home, you might come across the question of how you will elevate your home. Unfortunately, it can be difficult for homeowners to answer that question before beginning the home elevation process if they don’t know where to start or the details of different elevation techniques. Homeowners essentially choose between three techniques for elevating their homes to fix foundation damage, protect from flooding, or both.

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Technique 1– Extend the Walls of the Home Upward and Raise the Lowest Floor

Technique 1 is appropriate for homes with concrete or masonry walls but not for homes with other types of walls, such as those framed with wood studs, which would be more vulnerable to flood damage. This technique is usually appropriate when the base flood depth at the home is no more than 4 or 5 feet above grade. The elevation process begins with the temporary removal of the roof and roof framing in a single piece, if possible. This is commonly done with a crane. The roof is then stored on-site so that it can be reinstalled later.

The next step is to remove the windows and doors. After the roof, windows, and doors are removed, several courses of concrete blocks are added to the tops of the existing walls and the bottoms of the window openings. A corresponding number of blocks are removed from the tops of the window openings so that the size of the windows will remain the same. In addition, although not shown in Figure 11, concrete bond beams are formed in place at the tops of the extended walls to provide structural reinforcement.

Blocks are removed from the walls of the home at selected locations within 1 foot of the ground. The resulting openings will allow floodwaters to flow into and out of the lower area of the home so that the water pressures on both sides of the walls will remain the same. The roof and windows are then replaced, and a new wood-frame floor is constructed above the flood level. A homeowner who chooses Technique 1 may decide to build a new concrete slab floor instead of a wood floor. When this option is selected, compacted fill dirt or gravel is placed on top of the old slab, and the new slab floor is poured on top. Wall openings are not required because the area below the new floor is filled with dirt or gravel.

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Technique 2 – Convert the Existing Lower Area of the Home to Non- Habitable Space and Build a New Second Story for Living Space

When the base flood depth at the home is more than 4 or 5 feet above grade, the homeowner will usually find it more practical to add an entire second story to the home. The lower area of the home is then converted into a non-habitable space that may be used only for parking, storage, or access to the upper story. However, floodwaters may still enter this non-habitable lower area. For this reason, Technique 2, like Technique 1, is appropriate for homes with concrete or masonry walls, but not homes with other types of walls.

As in Technique 1, the repairs begin with the temporary roof and roof framing removal. After the roof is removed, the construction of the new second story begins. First, a new wood-frame floor is built on top of the existing lower-story walls. Next, the second-story walls are framed with metal or wood studs and set in place on the floor.

Some homeowners prefer that the second story be constructed of masonry, but wood- or metal-framing is more common, primarily because it is lighter and less expensive. The roof is replaced, and blocks are removed from the walls to allow floodwaters to enter and exit. Exterior sheathing is then added to the framed walls of the second story, the new windows are installed, and siding or stucco is applied to the sheathing.

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Technique 3 – Lift the Entire Home, With the Floor Slab Attached, and Build a New Foundation To Elevate the Home.

Technique 3 can be used for homes with wood-frame or masonry walls and is appropriate for a wide range of flood levels. This technique is very different from Techniques 1 and 2. Here, the entire home, including its slab floor, is lifted above the flood level, and new masonry foundation walls are built below it. The most common method of lifting the home is to place metal I-beams below the slab and raise the home with jacks.

First, trenches are dug to expose the foundation walls immediately below the slab. Holes are then cut in the foundation walls at intervals around the home, and tunnels are dug under the slab. Jacks are placed in the trenches, and large I-beams are inserted through the tunnels and allowed to rest on the jacks. Smaller I-beams are then inserted through the tunnels at right angles to the larger beams and positioned on top. The smaller beams support the slab when the home is raised.

The home is then jacked up. When the jacks have extended as far as possible, the home must be supported temporarily while the jacks are raised. Both the home and the jacks are usually supported on “cribbing”— temporary piles of crisscrossed timbers. The jacks are then used to raise the home higher.

This process is repeated until the home is raised to the desired height. The foundation walls are then extended upward with additional rows of concrete blocks. As in the previous techniques, openings are made in the walls within 1 foot of the ground so that floodwaters will be able to flow into and out of the area below the elevated floor. The jacks and beams are removed, and the openings left around the beams are filled with blocks.

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