FLOOD DAMAGE ASSESSMENT

for the

CARNTON PLANTATION SPRINGHOUSE

Franklin, Tennessee

May 2010

FLOOD DAMAGE ASSESSMENT

for the

CARNTON PLANTATION SPRINGHOUSE

Prepared for Jennifer Esler, CEO, Battle of Franklin Trust

by

Michael Thomas Gavin, Preservation Specialist

A Professional Services Project of the Tennessee Civil War National Heritage Area

May 2010

The Tennessee Civil War National Heritage Area (TCWNHA) is a statewide program

dedicated to the interpretation and preservation of Tennessee’s Civil War and Reconstruction legacies. Partially funded by the National Park Service, the TCWNHA

is one of several projects administered by the Center for Historic Preservation at Middle Tennessee State University.

Background: This visit was made on May 6, 2010, by Dr. C. Van West and Michael T. Gavin of the Heritage Area at the request of Jennifer Esler, CEO, Battle of Franklin Trust. East of the main house at Carnton and down a steep grassy slope sits a two-story springhouse. The brick structure was built atop a bubbling clear water spring to preserve the water source from impurities and to stockpile perishable foodstuffs in troughs and on shelves inside.

This springhouse, or dairy, served as a larder where the plantation’s milk, eggs, and butter were kept so they stayed cool and sweet. Brick buildings were high in thermal mass and retained the cool temperature emitted by the 55 degree water for long periods of time, making them ideal for storing dairy products. The rectangular c.1840s structure, constructed with hand-made brick molded and fired nearby, was placed over the source of a strong spring and rests on a low roughly hewn limestone foundation.

The springhouse has a gable-front cantilevered roof facing west, and is covered with split wooden shingles. Horizontal lapped wooden siding closes in the gable ends.

The items to be kept cool were placed upon flat rocks, troughs, or shelves in the lower level. This room was accessible by a low wooden door on the south side. For some reason, the bricks in the south wall were laid in Flemish bond.

Barred wooden frames were set into the bases of the other three walls (which are laid in American common bond) to provide ventilation. Brick jack arches support the walls above the vents. A short set of steps led up to a small porch at the front (west) of the building.

A four-panel wooden door provides access to the upper room, and 2” by 12” wooden joists support the tongue-and-groove boards of the second floor.

Description On the first weekend in May 2010, record rainfall caused widespread flash flooding in the greater Nashville area. The water came up quickly and inundated many places that had never before been under water. One of these locations was the site of the Carnton springhouse, where the water level rose higher than its walls and eventually lifted the roof right off of the building. Although the high water receded and set the roof back down on the structure almost exactly where it had been originally, considerable damage to the historic springhouse has occurred as a result of the storm.

As the water continued to rise, powerful currents swirled around the building. The lateral loads created by the water’s action (push-pull effect) were more than the old brick walls could withstand. The ebb and flow of the flood waters washed away the top fifteen courses of the east wall and caused severe damage to the lower part of the east side of the north wall.

The hydraulic pressure created a large V-shaped fissure in the wall which now threatens the structural integrity of the northeast corner. The wall has begun to bulge at the affected area and the situation needs to be addressed as soon as possible before this corner collapses.

In addition, the high water saturated the historic mortar, weakening it and even dissolving small portions at different places in the walls.

The traditional mortar mixture of sand, clay, and lime, while water-resistant, was never intended to be used below water for extended periods. Nineteenth-century masons knew that hydraulic mortars must be used for underwater applications, but they obviously did not envision a situation occurring at the Carnton springhouse where the use was required. The roof of the structure appears to be sound, although the east gable framing and siding is missing. The front steps and porch, made of modern materials, lie nearby after being separated from the structure by the action of the flood waters.

After the Water Recedes No other "element" is as destructive to buildings as water. After a building has been saturated and once the floodwaters recede, it is important that the drying process begin immediately. Most of the damaging effects of water, such as rot, rust, and spalling, can be minimized by reducing both interior and exterior moisture levels. This problem is compounded by the nature of the springhouse, i.e., its primary function naturally contributes to a high moisture level within the building. However, it is essential not to attempt to dry old buildings out too quickly by the application of heat. The result can be catastrophic: timber elements, including floors, doors and siding, may warp, twist or split; salts will migrate through old stone and brickwork, causing them to blister, powder and exfoliate; and many painted surfaces will peel and flake. The remedial work can be much more damaging than the flood itself. The best general advice is to dry the building down gently and slowly, first through natural ventilation, and, if necessary, with the aid of dehumidifiers and very low background heat. It is also useful to monitor the relative humidity within the property to ensure that moderate levels are maintained. Slow and gentle drying can take several months, but it is better than destroying irreplaceable historic fabric by acting in haste. The enclosed portions of the building, particularly the wall cavities, may retain water for long periods of time which can cause problems during subsequent restoration. Once the floodwaters recede, any remaining mud, dirt, and flood debris should be rinsed from all surfaces with fresh water as soon as possible. It is safer and easier to remove the mud while it is still wet. Do not wait until the material is dry. Beware of concealed hazards such as nails or broken glass hidden in silt or pooled water. Step carefully because floodwaters deposit a coating of mud, which can be very slippery underfoot. Make sure that all electricity is turned off before cleaning with water. Resist the temptation to start cleaning up right away. It is much better to assess the damage and make a coherent plan of action first. Avoid using high pressure water on historic materials and exercise extreme care when washing decorative features and damaged or loosened elements. Silt and mud will accumulate not only on the floor, but in wall cavities as well. To clean any remaining dirt and stains, use a standard non-sudsing household cleaning product as directed by the manufacturer. Special care should be used when working on or around historic materials. After cleaning, use a disinfectant to kill the germs, bacteria, and odor left by floodwaters. Keep in mind that floodwaters and the remaining silt are contaminated by sewage and chemicals. Protect your eyes, mouth, and hands, and wear a mask and rubber gloves when cleaning out debris left by floodwaters. Use disinfectants to wash your hands before eating. Salvaging Damaged Items Do not throw away materials (e.g. loose decorative elements, furnishings, etc.) indiscriminately, but salvage and retain as much as possible – even items thought to be badly damaged. Cleaning and steady drying out, together with conservation or repair may save them. If not, they may be used as models for new replica fixtures and fittings or found as a match in salvage yards. Floodwaters can carry even heavy items

a long way which you may find on your property, and these may well be vital to the restoration works of an upstream neighbor. Loose items that are missing from your property may turn up farther downstream. Foundation Erosion Water currents can erode soil beneath foundation walls. Although this situation is not common, when it does occur the building's foundation will be destabilized and repairs will be necessary. The best evidence of structural destabilization is the appearance of cracks in the foundation walls and in the brick courses above the foundation. However, not all cracks that appear after a flood are indications of long-term instability. Some may result from temporary expansion of clay soil around the foundation. When the soil returns to its natural water content, the cracks should shrink or, at the very least, not expand further. Cracks from actual foundation erosion, however, can be expected to worsen over time as the building settles slowly to its new soil support. The best indicator of this type of structural problem is cracks that move. Movement, particularly widening of cracks, is a sign of structural instability warranting careful examination by a qualified structural engineer or architect. Loss of Mortar The foundations of most older and historic buildings are masonry. Stone and brick foundation walls with soft lime mortar are very durable, although the lime mortar does not hold up well to water erosion. After the building dries out, the mortar of the masonry walls should be carefully inspected to ensure that it has not leeched from the joints and made the walls unstable. If a significant amount of mortar has been lost, it can usually be replaced without dismantling the wall. In many cases, a "loose" mortar can be poured into the joints to fill the voids. Make sure that replacement mortar is not too hard for the surrounding stone. If the foundation wall is constructed of limestone or other relatively hard stone, a standard tuck-pointing mortar may be used (ASTM "Type N," which contains one part hydrated lime to one part white Portland cement and six parts sand). In walls constructed of brick masonry, there will likely be less leeching of mortar than if the walls were constructed of stone. Nevertheless, these walls should be inspected for missing mortar and re-pointed with a soft lime mortar mixture that contains at least two parts hydrated lime to each part of white Portland cement and nine parts sand (known as ASTM "Type 0" mortar), unless there is reason to suspect a more serious structural problem created by the flooding. In many situations, impermeable, heavily-cementitious mortar will exacerbate deterioration in flood situations by holding the moisture in the masonry for longer and by causing salts to crystallize within the historic material. If this should become a problem, the wholesale removal and replacement of hardened Portland cement with weaker, porous, lime-based mortar will help the walls to dry out.

Summary The damage to Carnton’s historic springhouse is not overwhelming and can be reversed. An experienced restoration company would be able to stabilize the building, repair the brick walls, reinstall the second floor, align the roof properly, and return the structure to usability. Churches, schoolhouses, stores, banks, homes, courthouses, and barns in river and coastal communities often bear watermarks on the walls where owners pencil in the dates and levels of significant floods -- the 1937 Flood, the 1973 Flood, the Johnstown Flood. Yet many of these buildings have stood the test of time and survived inundation. While floodwaters can cause significant damage to historic buildings, they do not spell the end. With proper cleaning and drying out procedures, followed by expert historic restoration, the only reminder of floodwaters in historic structures should be a watermark and date on the wall. Enclosed with this report is a guide entitled Before and After Disasters: Federal Funding for Cultural Institutions, written and produced by Heritage Preservation in partnership with the Federal Emergency Management Agency (FEMA) and the National Endowment for the Arts (NEA) as a service to the American cultural community. The Preservation Briefs series, published by the National Park Service, provide useful technical information in dealing with the effects of floodwater damage to old or historic buildings. Copies are available from: Superintendent of Documents, Government Printing Office, Washington, D.C. 20402-9325. Or download directly from: http://www.nps.gov/history/hps/tps/briefs/presbhom.htm Several titles are particularly relevant: #1 The Cleaning and Waterproof Coating of Masonry Buildings #2 Repointing Mortar Joints in Historic Brick Buildings #6 Dangers of Abrasive Cleaning to Historic Buildings Michael Thomas Gavin Preservation Specialist Tennessee Civil War National Heritage Area