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Waukesha County. A cut stone foundation in good condition. Source: WHS - State Historic Preservation Office

If your historic house or building is over 100 years old, it might have a stone foundation. Your stone foundation will consist of limestone, sandstone or a variety of field or river stones. The problems you might face with your stone foundation will depend on the type of stone foundation you have in your historic structure.

Limestone and Sandstone Foundations

Limestone and sandstone foundations are constructed with cut blocks or rubble stones that can be small or large. Each block or stone is a different size and usually consists of broken pieces interlocked together. The color of these stones ranges from off-white to red, with shades of beige being the most typical colors.

Limestone and sandstone are a softer type of rock. To determine whether your stone is limestone or sandstone, use a screwdriver to scratch a stone in an inconspicuous interior location. Limestone will scratch with a bit of effort, while the even softer sandstone will scratch with little effort.

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Green Lake County. Field stone foundations were typically used for barns as seen in this photo. Source: WHS - State Historic Preservation Office

Field and River Stone Foundations

Field and river stone foundations are made up of many types of stones and rock that vary in color. The stones tend to be more rounded in shape. These stones are much harder than limestone or sandstone and will not scratch as easily.

Rubble Stone Foundations

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Typical rubble stone foundation as seen from the building's exterior. Source: Bob Yapp

Rubble stone foundations are the oldest type of construction technique used for stone foundations. This method dates back thousands of years, and was used in the earliest pyramids of Mexico, Central America and South America. Your Wisconsin house might have a rubble stone foundation if it dates from around 1850 to as late as 1890.

The footings of a rubble stone foundation wall consist of large, flat stones, usually made of limestone, laid at the bottom of the foundation trench. These stones are generally at least one-third wider than the stone wall placed above them. The foundation walls are constructed of random sized, uncut stones that are carefully fit into rows in an interlocking fashion. Lime-based mortar is installed between the stones.

The exterior of some rubble stone foundations is parged—covered with a lime-based, stucco-like coating. The parging is applied from the top of the foundation wall down to the stone footing. In many cases, lines were tooled into the above-ground parging while it was still wet to simulate the appearance of block stone.

If you have a rubble stone foundation, you have one of the most trouble-free and easily repaired foundations. Even if massive quantities of mortar have failed, the interlocked stones tend to stay in place.   

Block-Faced Rubble Stone Foundations

If your foundation has one layer of uniform, cut stone blocks on the exterior, it could be a block-faced rubble stone foundation. This type of foundation is essentially the same as a rubble stone foundation except it has a more finished, uniform look on the exterior.

Cut-Stone Block Foundations

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Iron Block Building, 1899

Milwaukee, Wisconsin. Here is a rubble stone foundation wall with an inverted brick arch detail. Source: WHS - State Historic Preservation Office

A cut-stone block foundation is constructed of stones cut into uniform blocks at the stone quarry. The stones were laid with lime-based mortar in early houses. The stones were laid with mortar and a small amount of Portland cement in later houses.

Typical Stone Foundation Problems

You may want to hire a preservation masonry professional to identify the cause of any problems you are having with your stone foundation.

The most common problems you are likely to encounter with your stone foundation are discussed below. Click the link on each subject to learn how to solve the problem.