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Replacing Your Historic Building Foundation | Wisconsin Historical Society

Guide or Instruction

Working with Professionals to Replace Your Historic Building Foundation

Replacing Your Historic Building Foundation | Wisconsin Historical Society

If your historic foundation has failed, either partially or entirely, you'll need to hire professionals to do repair or replacement work. You’ll know that your foundation requires repair or replacement if areas of your foundation’s masonry walls have collapsed or sunk enough that your windows and doors won't close.

Foundation replacement and major repair work is a huge undertaking. Therefore, you should hire a foundation contractor with a track record of working on historic buildings. The list below describes the key steps you should follow when working with a professional to replace all or part of your foundation.

Step 1: Consult a Structural Engineer

Your first step is to consult a structural engineer with historic house or building experience to determine how much of your foundation needs to be replaced. A structural engineer can determine what the problem is and the solution needed to fix it.

Step 2: Document the Look of Your Existing Foundation

Your foundation is a major architectural feature, so it is important to make your new foundation look as much like the original as possible to retain the historic look of your house or building. Before the old foundation is removed, document your existing, original foundation. Take lots of photographs and write down what you see. Use this documentation to ensure your foundation contractor understands what your new foundation should look like.

Step 3: Hire a Foundation Contractor

EnlargeImage of wood cribbing with steel beams.

Step 3 - Wood cribbing with steel beams. Source: Bob Yapp

Hire a contractor with proven experience replacing the foundations of historic houses and buildings. Make certain the contractor has all the necessary insurance and permits. Your house will be up in the air for a while and you don't want it to collapse, so be sure to have a structural engineer certify any plan your contractor proposes.

Step 4: Hire a House Moving Contractor

Your house or building will need to be lifted to remove the old foundation. To lift the structure, cribbing will have to be installed under its framing. Cribbing is a set of massive beams criss-crossed under the perimeter sill plate or sill beam as well as the floor joist framing. You should hire a house moving contractor to install the cribbing. The house moving contractor will use massive hydraulic jacks to lift your structure one to six inches above where the new foundation will be.

Step 5: Choose Materials to Match the Original Appearance

If you have a brick or stone foundation, be sure your new foundation has the same exterior look as the original. Most new foundations are done with poured concrete. With proper planning, a masonry contractor can veneer the exterior of the concrete with any original stones or bricks you salvaged, or with new bricks or stones that closely match the originals. Ask the contractor to pull out any stones or bricks and pile it on your lot. You may consider saving these for future use.

Step 6: Dig Out a New Basement

Consider having your contractor dig out your basement with nine- to ten-foot interior walls. Extra ceiling height in a basement can be a huge bonus for living or shop space. If you plan to use your basement for living space, you'll need a legal means of egress (a way to get out of the building that complies with building codes). This type of egress was not part of your original foundation, so it could disturb the historic original appearance of your house or building. To avoid this, select a location for the new egress that cannot be seen from the public right-of-ways (alleys and streets).

Step 7: Waterproof Your New Basement

Insist that your contractor tile your entire new foundation at the footing for exterior water management. Also be sure that the exterior of the foundation is insulated and waterproofed to meet the State Building Code (International Building Code).

Step 8: Finish the Job

When your house or building is set back onto the new foundation, the contractor will pour a new concrete basement floor. If the old basement staircase cannot be used, your contractor will build a new one. You should also make certain your contractor does the following to finish the job:

  • Hook up all your utilities again if your entire foundation was replaced.
  • Backfill the foundation with real, pulverized black topsoil for the final two feet of fill and tamp the dirt well.
  • Grade the ground to at least a five-degree pitch away from your foundation to provide adequate water drainage.

The information presented here is not intended to provide comprehensive technical advice or instructions on solving historic preservation issues. Any information contained or referenced is meant to provide a basic understanding of historic preservation practices. Read full disclaimer.