A04 - SOW.pdf

FORT DONELSON NATIONAL BATTLEFIELD

Dover, Tennessee

STATEMENT OF WORK:

Repair and Repoint Stone Walls at National Cemetery

PMIS: 290331

DATED:

Aug. 2, 2019

NATIONAL PARK SERVICE

SOUTHEAST REGION

EAST MAJOR ACQUISITION BUYING OFFICE

Fort Donelson National Battlefield (FODO) Statement of Work

Repair and Repoint Stone Walls at National Cemetery

BACKGROUND:

Fort Donelson National Cemetery is located in the town of Dover, TN in Stewart County. The historic stone wall that encompass the National Cemetery was built in 1867, completed in 1869, and has received subsequent renovations in the twentieth century.

The historic stone walls along the cemetery entrance road and surrounding the cemetery parking area were built by the Civilian Conservation Corps in the 1930's. The only known previous work has been periodic repointing of joints.

This project includes repointing fractured, loose, and missing mortar in all the stone walls located within the National Cemetery district. There are numerous large limestone blocks in the walls along with capstones that are significantly fractured and shall be replaced.

This project also includes restoring a section of the Civilian Conservation Corps stone wall that was recently struck by a vehicle. All pieces are present and historic plans and suitable images available to appropriately reassemble the damaged feature.

PROJECT OBJECTIVES:

To preserve the structural integrity and historic fabric of the cemetery stone wall that encompass Fort Donelson National Cemetery and the walls adjacent to the entrance road and parking area.

• Repair and maintain the historic stone walls for future generations.

• To repoint selected areas utilizing traditional and appropriate masonry standards, appropriate materials and tooling, and adhering to the Secretary of the Interior’s Standards for the Treatment of Historic Properties.

( https://www.nps.gov/tps/standards/treatment-guidelines-2017.pdf ) and NPS Preservation Brief 2 Repointing Mortar Joints in Historic Masonry Buildings (https://www.nps.gov/tps/how-to-preserve/briefs/2-repoint-mortar-joints.htm)

• Replace large limestone blocks in the walls that are severely fractured.

• Restore the section of parking area wall that was struck by a vehicle with as much of the original fabric as possible and to the original dimensions.

PLACE OF PERFORMANCE:

The project will take place at the Fort Donelson National Cemetery, Dover, Tennessee.

PERIOD OF PERFORMANCE:

All tasks and deliverables for this contract must be completed within 180 calendar days after issuance of the Notice to Proceed.

PROJECT SCOPE:

https://www.nps.gov/tps/how-to-preserve/briefs/2-repoint-mortar-joints.htm

Drainage:

Ensure all weep-holes are functional. Repair damaged stones and replace loose or missing mortar. Replace any missing stones with in-kind limestone. Stones for replacement will be pre-identified by park.

Wall Materials – Method for In-Kind Replacement and Mortar Matching

There was an active limestone quarry in the immediate Dover, Tennessee, area and possibly a source during the original construction of both the 1860s and 1930s walls. Comparison of material to local limestone should be the first source for consideration. Limestone quarrying was an active industry in Kentucky during the 1930s, and material from the wall may have been locally sourced. See https://quarriesandbeyond.org/states/ky/ky-photos2.html for possible sourcing materials.

The scope of services includes identifying an in-kind source of replacement limestone material.

Replacement limestone shall match the color, texture and properties of the original material and shall be available in sizes to match the original sizes of removed masonry units. Finishing of exposes surfaces of replacement masonry units shall mimic the rockface tooling of the original units.

The scope of services includes mortar analysis performed by the National Center for Preservation Technology and Training (NCPTT) to develop a compatible mortar mix for repointing and setting mortar. Goals for the mortar analysis are to establish the Sand: Cement:

Lime ratio based on the historic mortar AND to recover a cleaned sand sample that shall be the basis for the sand incorporated into the new mortar. Sand is the primary component of any mortar and has the greatest impact on the final visual appearance of the repointed joints.

Therefore, color control of the sand is critical to the success of the repointing campaign.

Stone Evaluation and Treatment:

Severely fractured masonry units shall be replaced. Prior to repointing the stone walls, determine which limestone masonry units are the most severely fractured. Mark them for replacement in kind, matching the original historic fabric and the proportions of the stone removed masonry units. Limestone masonry units proposed for replacement shall be marked with a China Red wax pencil to allow the NPS Contracting Officer Representative (COR) to backcheck and confirm the scope of proposed replacement.

Mortar Evaluation and Treatment

Examine all mortar joints on both historic stone walls to determine which specific areas of joints require repointing. Mortar joints that are cracked, deteriorated, eroded, contain voids, or are poorly bonded to masonry shall be repointed. All historic repointing projects shall conform to ASTM Standard Guide for Repointing Historic Masonry, E2260- 03. Deteriorated mortar joints shall be marked with a China Red wax pencil to allow the NPS COR to backcheck and confirm the scope of proposed repointing.

Remove all deteriorated mortar and replace missing mortar to maintain the structural properties, and historic fabric, improve the appearance, and form weathertight joints. Due to the stone walls being original from the 1930s Civilian Conservation Corps time period it is recommended that hand tools be used in the removal of deteriorated mortar, so as not to damage the masonry units surrounding the mortar. Contractor may use power tools to remove masonry units scheduled for replacement. Contractor shall remove all debris from the site and park.

Wall Specs:

https://quarriesandbeyond.org/states/ky/ky-photos2.html

The cemetery wall was constructed between 1867-68 and surrounds the core area of the cemetery. It is constructed of limestone blocks that are mortared together in seemingly random base courses with a relatively consistent sized capstone. The coursing and character of the wall varies over the length of the structure.

The cemetery wall in some locations is over six feet in height while in other locations the wall is nearly flush with the surrounding grade. This variable condition occurs on both sides of the wall.

The cemetery wall measures 1,665 linear feet and has a surface area of about 9,990 square feet.

The historic stone walls along the cemetery entrance road and surrounding the cemetery parking area were built by the Civilian Conservation Corps in the 1930's. These walls also consist of limestone blocks mortared together in seemingly random base courses with a relatively consistent sized capstone.

The stone walls along the front drive and front parking area consist of 675 linear feet of stone wall varying in height from 1 foot to 7 feet; this variable condition occurs on both sides of the wall.

A map of the cemetery walls is included at the end of this document.

Project Conditions:

Contractor shall not repoint mortar joints or repair masonry unless air temperatures are between 40 to 95 degrees Fahrenheit and shall remain so for at least 48 hours after completion of work.

Contractor shall prevent mortar used in repointing and repair work from staining surface of surrounding masonry and other surfaces. Contractor shall immediately remove mortar in contact with exposed masonry and other surfaces. Contractor shall protect ledges and projections from mortar droppings.

Sequencing/Scheduling:

Contractor shall perform masonry restoration in the following sequence:

1. Clean wall exterior stonework prior to repointing; use either pressure washer (low psi) or use brushes.

2. Field mark joints proposed for repointing, using China Red pencil or similar marking.

COR will review and approve or amend proposed repointing scope.

2. Rake out existing mortar from joints indicated to be repointed to a minimum depth of 2 to 2- 1/2 times the width of the joint (for most joints, this will be approximately 1 inch). Do not remove mortar in excess of one third the depth of the masonry unit above. Remove mortar using hand tools only. Electric or pneumatic chisels shall not be used. Contractor shall not spall or chip masonry. Any damaged masonry must be repaired.

3. Clean joints with water, rinse with maximum 100-psi pressure. Masonry joint shall be damp and without standing water.

4. Mix mortar carefully, measuring and mixing carefully to assure visual and physical characteristics. Dry ingredients shall be measured and volume and be thoroughly mixed before the addition of any water (more information on mix below).

5. Perform field test of new repointing work on masonry (a 3’ x 3’ area on the least visible masonry facade). Contact NPS Southeast Region Project Manager for approval of field test prior to continuing with work. This field visit shall occur at a minimum of 72 hours after the field test is performed to ensure that the repointing areas have cured. See additional information below.

6. Repoint existing mortar joints for remainder of structure or as specified by project. (See additional information below).

7. Clean existing masonry surfaces after repointing work is completed. Clean mortar from masonry face promptly to prevent staining. If necessary, after 24 hours of set time, scrub and wash surface to remove laitance using water and detergent, but no chemicals. Use natural sponges and bristle brushes. Wire brushes shall not be used.

Mortar Materials:

Ensure the consistency of the mortar, color, texture and tooling techniques match the original mortar. According to ASTM C 270, the mortar used in pointing shall be pre-hydrated in order to reduce the amount of shrinkage that can occur after it is placed in the joints.

CEMENT: ASTM C 150, Type II, white, non-staining unless it can be established that the original mortar used grey cement. For stonework and other masonry indicated, provide non-staining white cement complying with staining requirement of ASTM C91 for not more than 0.03% water-soluble alkali.

HYDRATED LIME: ASTM C 207, Type S or SA, Hydrated Lime for Masonry Purposes. This is high plasticity lime (not air entrained) instead of quicklime.

AGGREGATE: ASTM C 144, unless otherwise indicated.

SAND: Use natural rounded sand, clean, sound and washed. Provide sands that shall produce final mortar color and texture to match the existing, and with aggregate type and grading similar to existing mortar. The color of the sand shall be the primary factor used to make mortars that match original. Sand shall generally meet ASTM C 144, although sieving the sand may be needed to match the historic particle appearance and gradation.

WATER: Clean, free of oils, acids, alkalis and organic matter. No antifreeze compounds or other admixture shall be used.

CHEMICALS: No modern chemical additives shall be used.

Mortar Mixes:

PRE-BLENDED MORTAR MIXES PROHIBITED: Pre-blended masonry cement/mortar mix shall not be used since it is designed to produce mortars with compressive strength beyond what is common on most historic mortars.

PRE-BLENDED LIME MORTAR SUBJECT TO FIELD TEST: Pre-blended lime mortars shall not be used since the mortar will often not be an exact match to historic mortar. Pre-blended lime mortar shall never be used for “spot repointing” projects. If for complete repointing projects, the Historic Preservation Office confirms through a test panel that the pre-blended lime mortar is very close to color, composition and texture to historic mortar then it may be permissible.

However, in no circumstances shall the mortar differ from the mortar proportions requirements specified below.

MEASUREMENT AND MIXING: Measure cementitious and aggregate material in a dry condition by volume or equivalent weight. Do not measure by shovel, use known measure, mix materials in a clean mechanical batch mixer.

MIXING MORTAR: Thoroughly mix cementitious and aggregate materials together before adding any water. Then mix again adding only enough water to produce a damp, unworkable mix that shall retain its form when pressed into a ball. Maintain mortar in this dampened condition for one to two hours. Add remaining water in small portions until mortar of desired consistency is reached. Use mortar within 30 minutes of final mixing; do not re-temper or use partially hardened material.

ADMIXTURES: Do not use admixtures of any kind in mortar.

TOOLS: Use a pointing tool sized and shaped to the proper width for the joint being pointed.

Match the profile and tooling of the existing joints exactly. Apply mortar using wooden trowel to simulate the original mortar coating.

Mortar Proportions:

SPECIFICATIONS: NEW MORTAR MUST MATCH ORIGINAL IN COLOR, COMPOSITION,

TEXTURE AND TOOLING. New mortar must have greater vapor permeability and be softer than masonry units. It shall also be as vapor permeable and at least as soft as the historic mortar (not harder).

The original mortar shall be carefully analyzed by a person trained in this field. A preservation architect is highly preferred to help determine the appropriate proportions in advance of the project. In all cases, there should be a site visit with the contractor and Historic Preservation Office to perform a visual analysis of the mortar prior to the initiation of the project.

MIX PROPORTIONS BELOW ARE EXAMPLES ONLY AND MUST BE REVISED TO SUIT

PROJECT REQUIREMENTS ONCE EXISTING MORTAR HAS BEEN ANALYZED.

For structures dating from 1930 or earlier:

The final mortar mix shall have no more than 25% of total volume of the lime and Portland cement – combined – consisting of Portland cement unless testing of historic mortar demonstrates a higher Portland cement content. Generally, the proportions fall within ASTM Type K to L range. The range of acceptable mortar proportions is below:

1/10 part white Portland cement TO 1 part white Portland cement 3 parts lime 4 parts lime 12 parts natural sand 15 parts natural sand Water Water

Test Sample:

Utilizing the mortar formula provided for each unique stone wall, prepare one test sample at inconspicuous location. Test sample shall be approximately nine square feet in size and let cure at a minimum of 72 hours. Protect test sample from dirt and moisture. The National Park Service will inspect and review the test sample, and only proceed with project once assigned park cultural resources representative provides approval.

DELIVERABLES:

• Provide one-year warranty of all work.

GOVERNMENT-FURNISHED PROPERTY, MATERIAL, EQUIPMENT, OR INFORMATION:

FODO Facility Manager will designate a Contractor Staging Area. No government property or equipment will be furnished to the contractor.

SECURITY:

Park hours are from 8:00 AM until 4:30 PM. The Contractor may work on site from 8 AM to 4:30 PM Monday thru Friday. Contractor shall not work outside these hours or during federal holidays, without prior approval from the FODO Facility Manager.

OTHER UNIQUE REQUIREMENTS:

Close coordination with the park and COR is essential to maintain the park for visitor enjoyment during work to the greatest extent possible. Visitor safety is of paramount concern. Barricades, cones, etc. and all safety equipment must be in place prior to the start of work and during all work on site. FODO Facility Manager is the final authority for closure of any park facilities.

Coordination with park staff is necessary during any work performed to ensure park facilities and landscape are kept in good condition (i.e. exhibit items, walkways and vegetation, etc.).

QUALITY ASSURANCE REQUIREMENT:

The contractor shall develop and maintain a quality program to ensure services are performed in accordance with commonly accepted commercial practices. The contractor shall develop and implement procedures to identify, prevent, and ensure non-recurrence of defective services. As a minimum the contractor shall develop quality control procedures addressing the critical areas identified in this statement of work. The government will evaluate the contractor’s performance in accordance with the statement of work. The Contractor shall be responsible for verifying all measurements prior to ordering materials.

PROJECT PERSONNEL:

COR Information CO Information Name: David Hamby Name: Laurie Sherrod Address: Fort Donelson National Battlefield Address: Interior Region 2 South Atlantic Gulf

174 National Cemetery Dr. West Major Acquisition Buying Office Dover, TN 37058 2680 Natchez Trace Parkway

Office Phone: 931-232-0830 Tupelo, MS 38804 Cell Phone: 931-627-0569 Phone: 404-938-0178 Email: david_hamby@nps.gov Email: laurie_sherrod@nps.gov

CONTRACTED SERVICES STATEMENT:

Contractor employees, performing services under this order, shall be controlled, directed, and supervised at all times by management personnel of the contractor. Contractor’s management staff shall ensure that employees properly comply with the performance work standards outlined in the scope of work, specifications, and contract documents. The tasks, duties, and responsibilities set forth in the Statement of Work, and Specifications shall not be interpreted or implemented in any manner that results in any contractor employee creating or modifying Federal policy, obligating the appropriated funds of the United States Government, overseeing the work of Federal employees, providing direct personal services to any Federal employee, or otherwise violating the prohibitions set forth in the Federal Acquisition Regulation (FAR).

mailto:david_hamby@nps.gov

Photos below of the walls typical conditions.