Chicora Foundation, Inc., PO Box 8664,
Columbia, SC, USA, 29202, 803-787-6910
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Resetting Tilted Markers
1. It is absolutely critical that you dig around the stone very carefully. Steel shovels can easily damage stone. In fact, it is best if you excavate from the backside of the stone if at all possible -- that way, if you do slip, the mar will be on the reverse and not damage the inscription. If a stone is leaning backwards, however, you may have to dig on the face side since that is side away from the tilt. Regardless, always try to keep firm earth on one side, to provide a strong, compacted earth face against which to reset the stone. 2. Keep the sod and set it aside separately. Stockpile the spoil on a plastic tarp or in a wheelbarrow. Do not allow it to get mixed with the surrounding grass. Not only does this look unprofessional and inappropriate in a cemetery setting, but you may need this soil for backfilling. 3. Once the stone is free of earth, carefully remove it from the ground and lay it aside, outside the work area, on several 2x4s to support it. This will also make it easier to pick up again later. Examine the stone for any writing or carving that might have been obscured by soil. 4. If necessary, you may excavate the hole a little more -- usually about 3 to 6 inches deeper and about 6 inches more in diameter, but remember to leave one side compact. 5. You want to create a firm base for the stone and one that will evenly distribute its weight. If the base of the stone is relatively flat, set an even layer of bricks as a base, then about an inch of sand. If the base of the stone is pointed, then you may need to use only gravel and sand. 6. Replace the stone in the hole, be sure that enough stone remains below ground to support the upper portion and prevent it from retilting once it's reset. For eighteenth century stones about 40% of the stone was below ground level -- the amount buried is reduced through the nineteenth and twentieth centuries. 7. Position the stone level both vertically and horizontally. Use a builder's level to check. 8. Refill the excavation using the original spoil. It may be necessary to use occasional bricks or gravel to help assist holding the stone upright. Gravel may also assist in drainage around the stone, especially in heavy, clay soils. Tamp this material every few inches to ensure that it is well settled around the stone. Be careful with the tamping, however, to prevent damage to the stone. 9. Fill to encourage drainage away from the stone and reset the sod. All remaining spoil should be carried away. Leveling a Monument Some monuments require little more than releveling. Your first decision must be whether you can handle the task in a manner that will be safe for both you and the monument. If in doubt, do nothing and hire a stone conservator. If, however, the monument is small and you have the appropriate tools, then here are some suggestions. 1. While a level is often a vital tool, it is also important to realize that a monument is generally considered level when it appears level with respect to the surrounding terrain. 2. While steel pry bars are often used, they should only be used when you can ensure that the monument will not be damaged. Otherwise, it will be necessary to use a hoist and straps -- and this requires more equipment, skill, and care. 3. If the monument has no foundation it can generally be leveled using screenings, small pea gravel, or similar material. The key is to add material in shallow fills and ensure that the screenings are tamped down between lifts. If there is a previous concrete foundation and it, too, has slumped into the grave, then it will generally be necessary to remove the concrete and pour a new foundation. This is more complex and you probably should consult a conservator. Resetting Broken Markers in a Concrete Tab Some markers are broken off at ground level and found laying flat in the cemetery. This exposes them to damage from mowers, pedestrians, as well as increased damage from acid rainfall. Such stones may be good candidates for resetting in a new socket. First, you need to be certain that other than the one break, the stone is otherwise sound -- there should be no cracks, spalling, or other damage. Another condition is that the stone must be able to be reset without hiding or burying any of the inscription. If your stone meets these two conditions, creating a new socket for the stone is really pretty easy and involves essentially two steps -- creating the socket and them resetting the stone. 1. Identify the location where the stone is to be reset and excavate a hole 6-10 inches longer than the width of the tablet and 6-10 inches wider than the thickness. The excavation should be about 8 inches in depth. This hole will serve as a "ground form" for commercial gray Portland cement (this is one of the few instances where Portland cement is appropriate in cemetery preservation efforts).
4. The next step is to prepare a mortar mix that will retain
the stone in the prepared socket. One appropriate mortar is a 1:3 mix of natural
hydraulic lime (NHL) and sand. Natural hydraulic limes are rated by how
hydraulic they are -- 2.0, 3.5, and 5 -- with the higher numbers representing a
more hydraulic (and stronger) set. We recommend a NHL with a rating of 2 -- one
that is weakly hydraulic. One source for this NHL is
Virginia Lime Works.
This setting mortar is softer than the stone and any failure is likely to occur
in the mortar, preventing the stone from being broken. Another alternative that
you will see referenced in much preservation literature is a 1:2:9 mix of white (NOT gray) Portland
cement : hydrated lime : clean sand. This mix uses white Portland cement (ASTM
C-150, Type II) since it does not contain sulfates or other soluble
6. Never set a stone directly into cement. Not only does gray Portland cement contain impurities that will harm the stone, but the set concrete is far stronger than the stone. Any pressure to the stone (such as being hit by a lawn mower) will result in the stone snapping off at the base. The use of a form and an appropriate mortar mix helps ensure that the stone won't be damaged. Resetting Badly Broken Markers Some headstones are so damaged that resetting in a tab as
described above is simply not possible. One alternative is to reset them near
horizontal on (but NOT in) a concrete slab. There are several techniques for
this and the particular design will need to suit the circumstances. Here is one
example. 1. Begin by laying out the various fragments and determining the overall size of a support necessary. In this case the decision was made to create a support that was canted about 6-inches over about 3-feet and that was about 6-inches in height at the base and about a foot high at the head. 2. A form was created over a below grade excavation. Because
of the size of the concrete support being created, threaded stainless steel rod
was used to help reinforce the concrete pour. 3. We used a normal "ready-mix" type concrete, but you might
want a fiberglass reinforced mix to eliminate the need for other reinforcement.
After the concrete is poured and set, the form is removed and the ledger is
arranged on the concrete, set in a mortar mix. One appropriate mortar is a 1:3
mix of natural hydraulic lime (NHL) and sand. Natural hydraulic limes are rated
by how hydraulic they are -- 2.0, 3.5, and 5 -- with the higher numbers
representing a more hydraulic (and stronger) set. We recommend a NHL with a
rating of 2 -- one that is weakly hydraulic. One source for this NHL is
Virginia Lime Works.
This
4. Afterwards the stone is infilled using an appropriate conservation mortar, such as Jahn or U.S. Heritage. For this you will need a stone conservator. You may also select a lower, less canted basal support. In such a reset, the stone is said to be "floated" on a lime-based mortar bed. A 4-inch concrete foundation, the outline of the stone, is poured and allowed to cure. The surface of this slab is canted -- generally about 1-inch for every 1-foot. It is important to cant the bed to ensure that there is positive drainage and water (that is typically acidic) does not collect on the face of the monument. The stone fragments are then reassembled snuggly on a bed of lime-based mortar. Cracks and losses are infilled using an appropriate conservation mortar. |
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Only
gravestones that are severely tilted should be reset since there is always the
possibility that resetting may cause other damage to the stone. Assume that all
stones are fragile and have some form of internal cracking or damage.
2.
Prepare a wood form to create a slot in the concrete. This slot will be used to
hold the stone upright. The wood can consist of 2x6s or 2x8s depending on how
deep the socket needs to be to provide support to the stone. You will likely
also need to use shims to make the form about ¼-inch
wider on each of the four sides than the stone (in other words, the slot in the
concrete form will be ½-inch larger than the
stone). Oil the wood so it will more easily slip out of the ground form as the
concrete sets up.
3. Place
several inches of concrete at the base of the ground form, set in the prepared
wooded slot, and fill the ground form with concrete to within a couple inches of
the ground level (be certain that your slot form extends up beyond the concrete
so you can remove it). Allow the concrete to set up for several hours and remove
the wood form when the concrete will hold its shape (if you wait too long
removing the wood form will become very difficult; if you attempt to remove it
too soon, the wet concrete will slump). Allow the form to set up for at least 24
hours and preferably 72 hours.
salts that
can cause staining and efflorescence. The hydrated lime (ASTM C-207, Type S)
helps provide high plasticity and water retention with a safe degree of
strength. The concern with the use of Portland cement to gauge the mortar
(increasing the speed of the set) is that some research suggests that this
dramatically reduces the longevity of the mortar. The use of a NHL mix is
preferred. 
5.
Place mortar mix in the base and on the sides of the slot, set the marker, and
ensure that it is straight. If necessary, additional mortar can be added to the
sides of the slot and small pieces of soft waste stone or plastic shims can be used to
hold the stone in position while the mortar sets. 
setting
mortar is softer than the stone and any failure is likely to occur in the
mortar, preventing the stone from being broken.