Tomb Conservation Guidelines
Limewashing Guidelines
All stucco tombs were painted for decoration and protection with limewashes of various colors. Traditional and acrylic- amended limewashes are still recommended as the most serviceable protective coatings for stucco covered tombs. Evidence of ochre, red, and gray colored and white limewashes has been found on tombs as well as in numerous historical images. Individual tombs can be analyzed to determine their original colors and refinished to match the most significant historical color.
Stable lightfast alkali-proof cement pigments should be used to recreate these colored washes. For most tombs, a plain unpigmented whitewash is recommended. Contact Save Our Cemeteries for a color chart of traditional limewashes currently in use for the Alley 9L restoration project and for information on limewash recipes and material sources.
If slaked lime putty is not available, thoroughly mix hydrated lime (Type S) with water to a putty consistency, top with water, and allow it to stand covered for at least 24 hours; two weeks is preferable. Before applying, sieve the lime through a fine screen and thin with water to the consistency of light cream. To increase adhesion of paint to the old surface, a diluted acrylic emulsion can be added to the mixing water in a ratio (by volume) of approximately 1 part acrylic to 10 parts water just before use. If a pigmented limewash is used, the correct ratio of pigment to limewash should first be determined by the prepartion of small test batches, applied to the tomb surface and allowed to dry.
Pigmented limewashes should be mixed in large enough quantities for each single application coat and no less than 1-2 gallons. White limewash is best pigmented by first mixing the total amount of pigment required in a small amount of water or limewash and then adding that into the larger quantity to be pigmented. Never add the pigment dry into the limewash as it will not evenly disperse and cause streaking. Mix well by hand, or with a mechanical mixer, for not less than 15 minutes.
Before application of any paint finishes, stucco surfaces should be free of dirt, debris, oil, biological growth, and flaking paint; otherwise the limewash will not bond. Heavy accumulations of earlier finishes can be easily removed by hand scrapping aided by low pressure water such as a garden hose. More specialized methods of paint removal are possible; however these are best performed by an experienced professional, as they can cause great damage to stucco and stonework as well as cause personal injury if misapplied.
Dampen the wall with water and then apply the limewash with traditional distemper or tampico fiber brushes, brushing it on in short multi-directional stroke applications. As the water evaporates from the limewash, rework, or polish the surface finish for even distribution. Due to the rapid drying, limewash should be applied in small areas to avoid drying at the overlap. Apply several thin coats (at least three), allowing each coat to dry before applying the next coat. Dampen the surface between coats and avoid working in direct sun.
If used properly, limewash finishes are durable, inexpensive, easy to apply and environmentally and user friendly. Their translucent appearance cannot be duplicated by opaque modern synthetic “latex” paints and their eventual build-up is easily removed unlike latex and oil-based paints.
Text adapted from St. Louis Cemetery No. 1 Guidelines for Preservation and Restoration.
Masonry Guidelines
All masonry work including brickwork, stucco and stone should be executed under optimum weather conditions to ensure the success of the repairs. No work should be executed or cured during weather below 40 degrees Fahrenheit. To prevent too rapid drying in temperatures over 85 degrees Fahrenheit, masonry work may require repeated misting and protection from the sun with damp burlap, canvas or plastic sheeting and canopies.
Brickwork repairs account for the majority of the work required at most tombs. All brick joints should be inspected for missing and deteriorated mortar, and loose bricks should be removed and cleaned for resetting. Defective joints should be raked by hand to 1″ in depth or down to sound mortar. All dirt and loose debris should be removed before repointing or resetting. Masonry should be well dampened then bricks set and joints repointed with a compatible mortar mix that matches the original mortar or its properties.
A suitable mortar mix should employ a lime putty or hydraulic lime. A lime and Portland cement blend can be used for roofs where harsh conditions prevail. Two such recommended mixes which have been used with good results in Lafayette 1 and St. Louis Cemeteries No. 1 and 2 are as follows: 1 part white Portland cement to 2 parts lime putty (slaked for a minimum of 3 months) or hydrated masons lime (Type S) to 9 parts clean masons sand. Where available, a hydraulic lime mortar is preferable; made from 1 part Riverton HHL (hydrated hydraulic lime) to 3 parts masons sand (all parts by volume).
Masonry cracks in the stucco and brickwork often occur at the roof, corners, and occasionally in the walls, if uneven settlement has occurred. Superficial cracks can be mortar repaired; however large or deep structural cracks will need to be grouted or stitched using specialized materials and techniques by a qualified professional.
Missing and broken bricks should be replaced with those of similar size and water absorption properties to ensure compatibility. Recycled bricks are available from local suppliers. Wherever possible, original construction methods should be duplicated, such as bonding and coursing patterns, unless these have failed due to inadequate support or subsequent modifications to the tomb. Any changes to construction details should be carefully considered before execution, as these can cause serious future problems. Before relaying, all bricks should be thoroughly soaked in water for several hours to reduce suction. Finally, joints should be raked back to provide a mechanical key for new stucco.
All stucco should be gently sounded with an acrylic mallet to determine where it is detached. When tapped with the mallet, detached stucco produces a characteristic hollow sound. Remove non-ornamented detached stucco by hand with a hammer and masonry chisel. Cut the edge of sound stucco at an inward angle to provide a dovetail key for new stucco. Remove all loose dirt and debris from the masonry substrate with soft bristle brushes and dampen well all surrounding stucco and masonry brickwork prior to and after the application of new stucco.
Always apply stucco repair patches to the level of the existing stucco. Do not feather edges of new stucco repairs over adjacent existing stucco. Match existing texture using the appropriate wood or rubber float. If stucco was scored to replicate ashlar block, allow stucco to set until thumbprint hard and strike a shallow joint line in the same dimension and manner as the original. Flush fill all surface cracks and holes in order to provide a water tight skin. Finally, make sure all horizontal surfaces allow for proper water disposal.
A highly durable and compatible mix for new stucco and stucco repairs is 1 part Riverton hydrated hydraulic lime (HHL) to 2 parts fine masons sand (by volume). A blend of 1 part white Portland cement to 2 parts lime putty to 6 parts fine masons’ sand may be used if the hydraulic lime is not locally available. Sound ornamental stucco, such as cornice moldings and pilasters, should always be preserved. However, missing areas requiring replacement can be duplicated carefully by recording the profile with a molding gauge and cutting a matching sheet metal template, which can then be used by a skilled mason to re-create the molded work in place. Hand rebuilding of moulded work should be avoided.
Text adapted from St. Louis Cemetery No. 1 Guidelines for Preservation and Restoration.
Marble Tablets & Sculpture
A fine-grained, white calcitic marble was used most frequently for closure tablets, tomb slabs, plaques and sculpture. Several other stones are also found in lesser quantities, including a medium to large grained grey veined white marble and a dark gray limestone. By far the most serious problem affecting tomb stonework is the deformation (bowing) and breaking of the closure tablets and their surface erosion (‘sugaring’) from atmospheric weathering.
Marble, being highly crystalline, under-goes a volume increase with each thermal cycle, leading to permanent expansion and distortion. If restricted, eventual cracking and breaking of the stone often occurs in order to relieve this built-up stress. This is clearly visible in the many bowed and deformed S- and C-shaped closure tablets. Their poor design as large thin (1″) slabs tightly fitted in the tomb opening and fine-grained structure have contributed significantly to their structural deformation and breakage in New Orleans’ hot damp climate.
Surface erosion and loss of inscription and carved detail on marble and limestone are due to these stones’ chemical sensitivity to acidic conditions caused by atmospheric pollution and micro-flora. Black staining commonly found on horizontal surfaces and joints is the result of black fungal growth.
Frequently, due to the conditions outlined above, inscription tablets and various architectural and sculpted elements become stained, eroded, fragile and fragmented, often disassociated from their original location. In such instances, if conservation work cannot proceed immediately, stonework should be photographed where found, and a precise record kept which will identify all of the elements. This is useful should elements be stolen and later retrieved. All of the fragments should be marked (on their reverse side) with their location using chalk or a graphite pencil. A copy of the record should be made and stored with the actual element, and the original copy placed with the governing body of the cemetery or preservation society.
Fragmented and damaged enclosure tablets and sculpture should be repaired as soon as possible before pieces become lost or damaged from handling. A trained conservator or technician is best qualified to perform this work.
Where tablets are missing or need replacement, fine white marble should be selected over other stones. Tablets should be sized to a minimum of 1 1/2″ in thickness. Where possible, new and reinstalled tablets should be shaved at the bottom ¼” and placed on lead or polyethylene foam shims to allow for thermal movement.
The original single or double pinning assemblies used to retain the tablet in place should be reused or substituted in kind. If wooden blocks were used to anchor the pin into the vault masonry, these can be replaced if necessary with more durable composite wood to avoid future insect attack. Only non-corrosive stainless steel or bronze pins should be used. These are available from the Archdiocesan Cemeteries office.
The recent substitution of gray granite and blue anorthosite for many of the historic white marble tablets is significantly impacting the historic appearance of the site as a whole. These new closure tablet replacements are dramatically different both in color and reflectivity from their marble precedents. While the closure tablet issue may seem like a minor aesthetic debate, it is indicative of the larger question of the contribution of repetitive architectural elements to the visual integration of the overall site and the impact of such changes. Durable white marble is available from local stone suppliers at comparable costs, and should be used in lieu of granite at this site.
Text adapted from St. Louis Cemetery No. 1 Guidelines for Preservation and Restoration.
Metalwork
Years of deferred maintenance and vandalism have left the metalwork in the cemetery in very poor condition. Theft is the major cause of most missing metalwork in the cemetery. Many of the enclosures are completely or partially missing, the most vulnerable elements being the gates, crosses, and decorative details. Smaller items, such as the relief sculpture and cast iron urns, have also been lost to theft. The deteriorated condition of the metalwork sends a message that it is expendable and makes it easier for elements to be wrenched loose.
Other commonly found conditions include: structural failure and corrosion, racking, and failed alterations and repairs. Treatments include stabilization with temporary measures, surface protection, repairs and replacement.
Temporary measures can do much to stabilize loose and detached metalwork and safeguard its loss to theft and vandalism. Bracing and wiring loose elements and installing locks on gates allow elements to remain in place. If removal is necessary, all elements should be tagged and stored in a safe and dry location until repairs can be undertaken.
Most if not all cemetery metalwork traditionally received some type of coating for protection. The application of paints and coatings are therefore both historically appropriate and necessary to preserve the decorative metalwork. Prior to applying any finishes, the metalwork must be properly prepared or the finishes will fail prematurely or even cause accelerated corrosion by trapping moisture underneath. Careful cleaning is also useful in revealing structural defects that might require attention prior to refinishing. All cleaned ironwork must be immediately treated with a quality inhibitive primer or coating to prevent the formation of rust which will interfere with adhesion of the new coating. This is especially important in the humid environment of New Orleans. See More on Protective Coatings.
Most repairs to metalwork require a qualified professional. While repair using original techniques is expensive because of the specialized skills needed, there are excellent reasons for making the investment. See the full discussion of cleaning, protection, repair and replacement options in the St. Louis Cemetery No. 1 Guidelines for Preservation and Restoration.
Metalwork Protective Coatings
Before any new finishes are applied, the metalwork must be thoroughly cleaned, and all small holes and pitting that might hold water should be filled with a quality patching material designed for metal.
A coating system should be selected that can be easily applied depending on the application context (on- or off-site). Only paints meeting all the current health, safety, and environmental standards should be used. Acrylic paints are building a relatively good track record for protection of metalwork and should be used over other irreversible coatings such as epoxy based paints.
Paints and coatings should only be applied when surfaces are perfectly dry and temperatures are above 50 degrees F. Brush applying paint insures the best coverage. If railings are removed, they can be spray painted in a controlled environment followed by “back-brushing” to ensure that the paint is worked into the surface and into all joints.
Three-coat work consisting of a primer, intermediate, and finish coats is standard for bare metal. A good quality corrosion inhibitive, “direct-to-metal” (DTM) primer should be used followed by two compatible finish coats. If the paint is applied in thin coats, there will be better adhesion, build-up will be minimized, and the detail of the metalwork will be less obscured.
Archival evidence suggests that architectural wrought iron was sometimes wax and oil treated, rather than painted. In these cases, a microcrystalline-based wax formulation can be used to protect and enhance the metalwork. This method has been extensively used with success on outdoor bronze sculpture and at St. Louis Cemetery No. 1.
The wax mixture is applied hot to a previously cleaned and heated surface to chase off condensed moisture on the surface and to insure adequate flow of the wax for complete coverage. Different formulations are possible, including mixtures of microcrystalline and low melting point polyethylene waxes with pigments such as lampblack, and are best prepared and applied by a professional conservator.
See the full discussion of metalwork cleaning, protection, repair and replacement options in the St. Louis Cemetery No. 1 Guidelines for Preservation and Restoration.