B08_Solicitation_-_Att_1_-_Specifications.docx

STGE 351091 2-24-2026

SECTION 040140.62

STONE WALL REHABILITATION

GENERAL

SCOPE OF WORK

Project Location: Ste. Genevieve National Historical Park – 339 St. Marys Rd, Sainte Genevieve MO 63670 Building(s) Name/Identifier: Green Tree Tavern – 244 St. Marys Rd, Ste. Genevieve MO 63670

SUMMARY

Section includes reconstructing historic limestone retaining wall with lime mortar.

PREINSTALLATION MEETINGS

Preinstallation Conference: Conduct conference at Project site.

ACTION SUBMITTALS

Product Data: For each type of product.

Samples: For each exposed product and for each color and texture specified.

Approved Mortar Mix Proportion Specification.

INFORMATIONAL SUBMITTALS

Quality-control program.

QUALITY ASSURANCE

Stone Rehabilitation Specialist Qualifications: Engage an experienced stone masonry firm to perform work of this Section. Firm shall have completed work similar in material, design, and extent to that indicated for this Project with a record of successful in-service performance. Experience in only installing standard unit masonry or new stone masonry is insufficient experience for historic stone rehabilitation work.

Quality-Control Program: Prepare a written quality-control program for this Project to systematically demonstrate the ability of personnel to properly follow methods and use materials and tools without damaging stonework. Include provisions for supervising performance and preventing damage.

Temperature: Maintain wall temperature between 40 and 95 degrees F. To the extent possible, repoint in the shade, away from strong sunlight in order to slow the drying process.

PRODUCTS

MORTAR MATERIALS

Hydrated Lime: Natural Hydraulic Lime (NHL) 3.5 Mortar Sand: ASTM C144.

Match size, texture, and gradation of existing mortar sand as closely as possible. Blend several sands if necessary to achieve suitable match.

Color: Natural sand or ground marble, granite, or other sound stone of color necessary to produce required mortar color.

Water: Potable.

MORTAR MIXES

Measurement and Mixing: Measure cementitious materials and sand 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.

Do not use admixtures in mortar unless otherwise indicated.

Mixes: Mix mortar materials in the following proportions:

Rebuilding (Setting) Mortar by Volume: 1 part portland cement, 1 part lime, and 6 parts sand.

Rebuilding (Setting) Mortar by Type: ASTM C270, Proportion Specification, Type N unless otherwise indicated.

REPLACEMENT STONE UNITS

Stone Matching Existing: Contractor must demonstrate that any portion of existing historic stone is insufficient to conduct the work. Expectation is wall is fully rehabilitated with existing stone. Natural building stone of variety, color, texture, grain, veining, finish, size, and shape that match existing stone.

For existing stone that exhibits a range of colors, texture, grain, veining, finishes, sizes, or shapes, provide stone that proportionally matches that range rather than stone that matches an individual color, texture, grain, veining, finish, size, or shape within that range.

Shaping New Stone: Shape each new stone so that, when it is set in final position, the rift or natural bedding planes will match the rift orientation of existing stones. Each stone shall be shaped using hand tools (hammer and chisels) to ensure stones have consistent characteristics.

EXECUTION

STONE REHABILITATION BY RECONSTRUCTING

At locations indicated, remove all stone which is to be reused. Carefully remove entire units from joint to joint, without damaging surrounding stone, in a manner that permits replacement with same existing full-size units.

Support and protect remaining stonework that surrounds removal area.

Notify COR of unforeseen detrimental conditions immediately for determination of how to proceed.

Remove in an undamaged condition all stone.

Remove mortar, loose particles, and soil from stone by cleaning with hand chisels, brushes, and water.

Clean stone by removing mortar, dust, and loose particles in preparation for stone resetting.

Replace removed damaged stone with other removed stone in good condition only as substantiated as necessary and approved by the COR in writing.

Set stone with rebuilding (setting) mortar and with completely filled bed, head, and collar joints. Butter vertical joints for full width before setting, and set units in full bed of mortar unless otherwise indicated.

Curing: Cure mortar by maintaining in thoroughly damp condition for at least 72 consecutive hours, including weekends and holidays.

Hairline cracking within the mortar or mortar separation at edge of a joint is unacceptable. Completely remove such mortar and repoint.

FINAL CLEANING

After mortar has fully hardened, thoroughly clean exposed stone surfaces of excess mortar and foreign matter; use wood scrapers, stiff-nylon or -fiber brushes, and clean water, applied by low-pressure spray.

Do not use metal scrapers or brushes.

Do not use acidic or alkaline cleaners.

END OF SECTION

Div. 4 V. 2021-10-18 STONE REPOINTING 040140.62 Page | 1