UFGS 04 01 20.70 - Unit Masonry Cleaning and Restoration.pdf

USACE / NAVFAC / AFCEC / NASA UFGS-04 01 20.70 (November 2015) Preparing Activity: USACE Superseding UFGS-04 01 00.91 (May 2012)

UNIFIED FACILITIES GUIDE SPECIFICATIONS

References are in agreement with UMRL dated January 2016

SECTION TABLE OF CONTENTS

DIVISION 04 - MASONRY

SECTION 04 01 20.70

UNIT MASONRY CLEANING AND RESTORATION

11/15

PART 1 GENERAL

1.1 REFERENCES

1.2 DEFINITIONS

1.2.1 Aggregates

1.2.2 Biocides

1.2.3 Binder

1.2.4 Dispersed Lime Crack Injection

1.2.5 Consolidant

1.2.6 Dutchman

1.2.7 Harvested

1.2.8 In situ

1.2.9 Joint Sealant

1.2.10 Lead Flashing

1.2.11 Lime Wash

1.2.12 Mockup

1.2.13 Mortar

1.2.14 New Elements

1.2.15 Patch

1.2.16 Remediate

1.2.17 Remove

1.2.18 Replace

1.2.19 Repoint

1.2.20 Retool

1.2.21 Stucco

1.2.22 Surface Treatment

1.2.23 Test Panel

1.2.24 Tuckpointing

1.2.25 Water Repellent

1.2.26 Wall System

1.2.27 Masonry Treatment Requirement (MTR)

1.2.28 Saturated Surface Dry (SSD)

1.3 ADMINISTRATIVE REQUIREMENTS

1.3.1 Pre-Installation Meeting

1.4 SUBMITTALS

1.5 QUALITY CONTROL

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1.5.1 Quality Control Plan

1.5.2 Qualifications

1.5.2.1 Historic Masonry Consultant

1.5.2.2 Masonry Firm

1.5.2.3 Field Supervisor

1.5.2.4 Masonry Applicator

1.5.3 Project Training Definition and Use

1.5.4 Mortar Analyst

1.5.5 Documentation

1.5.6 Cleaning and Restoration Methods

1.5.6.1 General Procedure

1.5.6.2 Cleaning Products and Procedures

1.5.7 Masonry Restoration Products and Procedures

1.6 DELIVERY, STORAGE, AND HANDLING

1.7 PROJECT/SITE CONDITIONS

1.7.1 Environmental Requirements

1.7.2 Masonry Installation Requirements

1.8 WARRANTY

1.8.1 Cleaning Warranty

1.8.2 Repair Warranty

PART 2 PRODUCTS

2.1 CLEANING MATERIALS

2.1.1 General Requirements

2.1.2 Paint Removers

2.1.3 Chemical Cleaners

2.1.4 Biocides

2.1.5 Liquid Strippable Masking Agent

2.1.6 Cleaning Implements

2.1.7 Water

2.2 REPAIR MATERIALS

2.2.1 General

2.2.2 Mortar and Stucco

2.2.2.1 Testing and Matching

2.2.2.2 Replacement Mortar and Stucco

2.2.2.3 Binder Content

2.2.2.4 Repointing Mortar

2.2.2.5 Admixtures

2.2.3 Crack Injection

2.2.4 Replacement Masonry Materials

2.2.4.1 Clay Brick

2.2.4.2 Stone

2.2.4.3 Terra Cotta

2.2.4.4 Architectural Precast Stone

2.2.5 Surface Treatments

2.2.5.1 General

2.2.5.2 Consolidants

2.2.5.3 Water Repellents

2.2.6 Miscellaneous Materials

2.2.6.1 Cementitious Grout

2.2.6.2 Metal Attachments

2.2.6.3 Lead Flashing

2.3 EQUIPMENT

2.3.1 Cleaning Equipment

2.3.1.1 Sandblasting

2.3.1.2 Water Blasting

2.3.1.3 Alternative Blasting Equipment

2.3.2 Spray Equipment

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2.3.3 Drilling Equipment

2.3.4 Compressed Air Supplies

2.3.5 Material Handling and Associated Equipment

2.3.5.1 Mixing, Transporting, and Placing Job Materials

2.3.5.2 Associated Equipment

2.4 Mortar Mix

2.4.1 General

2.4.2 Batching

2.4.3 Cement and Lime Proportions

2.4.4 Sand Proportions

PART 3 EXECUTION

3.1 EXAMINATION

3.1.1 Field (In Situ) Mortar Examination

3.1.2 Taking and Preparation of Samples

3.2 PREPARATION

3.2.1 Protection

3.2.2 Surface Preparation

3.2.3 Equipment and Techniques Demonstration

3.3 MASONRY CLEANING

3.3.1 General

3.3.2 Chemical Cleaners

3.3.3 Paint Removal

3.3.4 Water Cleaning

3.3.4.1 Pressure Spraying

3.3.4.2 Hand Scrubbing

3.3.4.3 Rinsing

3.3.5 Chemical Cleaning

3.3.5.1 General

3.3.5.2 Surface Prewetting

3.3.5.3 Acidic Chemical Cleaning

3.3.5.4 Alkaline Chemical Cleaning

3.3.5.4.1 Prewash Phase

3.3.5.4.2 Afterwash Phase

3.3.5.5 Rinsing and pH Testing

3.4 MASONRY REPAIR

3.4.1 General

3.4.2 Repointing Masonry

3.4.2.1 Wall Preparation

3.4.2.2 Presoaking Masonry / Mortar Consistency / Lifts

3.4.2.3 Compression / Joint Finish / Curing

3.4.2.4 Protection

3.4.3 Retooling Stone Masonry In situ

3.4.4 Masonry Removal and Replacement

3.4.5 Material Repair

3.4.5.1 Selective Demolition

3.4.5.2 Application of Substitute Repair Materials

3.4.5.3 Patch Anchors

3.4.5.4 Cleanup

3.4.6 Dutchman Repairs

3.4.7 Crack Injection with Dispersed Hydrated Lime (DHL)

3.4.7.1 General

3.4.7.2 Application of DHL

3.4.7.3 Tools and Equipment

3.4.8 Surface Treatments

3.4.8.1 Stucco

3.4.8.2 Limewashes

3.4.8.3 Water Repellents Infiltration

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3.4.8.4 Stone Consolidants

3.5 INSTALLATION OF NEW ELEMENTS

3.5.1 Structural Upgrades

3.5.2 Joint Sealant and Lead Flashing

3.6 FINAL CLEANING

3.7 PROTECTION OF WORK

3.8 DEFECTIVE WORK

3.9 FINAL INSPECTION

-- End of Section Table of Contents --

SECTION 04 01 20.70 Page 4

USACE / NAVFAC / AFCEC / NASA UFGS-04 01 20.70 (November 2015) Preparing Activity: USACE Superseding UFGS-04 01 00.91 (May 2012)

UNIFIED FACILITIES GUIDE SPECIFICATIONS

References are in agreement with UMRL dated January 2016

SECTION 04 01 20.70

UNIT MASONRY CLEANING AND RESTORATION

11/15

NOTE: This guide specification covers the requirements for restoration and cleaning of masonry in historic structures.

Adhere to UFC 1-300-02 Unified Facilities Guide Specifications (UFGS) Format Standard when editing this guide specification or preparing new project specification sections. Edit this guide specification for project specific requirements by adding, deleting, or revising text. For bracketed items, choose applicable items(s) or insert appropriate information.

Remove information and requirements not required in respective project, whether or not brackets are present.

Comments, suggestions and recommended changes for this guide specification are welcome and should be submitted as a Criteria Change Request (CCR) .

PART 1 GENERAL

NOTE: Where the words "as indicated" are used, ensure that sizes, positions and other designated information are indicated on the design drawings.

The following publications, from the United States Department of the Interior - National Park Service, provide useful guidance in the restoration of historic masonry and may be included as addenda to the specifications.

The Secretary of the Interior's Standards for the Treatment of Historic Properties with Guidelines for Preserving, Rehabilitating, Restoring, and Reconstructing Historic Buildings (1995).

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Preservation Brief #1 - (2000) Assessing Cleaning and Water-Repellent Treatments for Historic Masonry Buildings

Preservation Brief #2 - (1998) Repointing Mortar Joints in Historic Brick Buildings

Preservation Brief #6 - (1979) Dangers of Abrasive Cleaning to Historic Buildings

Preservation Brief #7 - (1979) The Preservation of Historic Glazed Architectural Terra-Cotta

Preservation Brief #22 - (1990) The Preservation and Repair of Historic Stucco

Preservation Brief #38 - (1995) Removing Graffiti from Historic Masonry

1.1 REFERENCES

NOTE: This paragraph is used to list the publications cited in the text of the guide specification. The publications are referred to in the text by basic designation only and listed in this paragraph by organization, designation, date, and title.

Use the Reference Wizard's Check Reference feature when you add a RID outside of the Section's Reference Article to automatically place the reference in the Reference Article. Also use the Reference Wizard's Check Reference feature to update the issue dates.

References not used in the text will automatically be deleted from this section of the project specification when you choose to reconcile references in the publish print process.

The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only.

AMERICAN CONFERENCE OF GOVERNMENTAL INDUSTRIAL HYGIENISTS (ACGIH)

ACGIH 0100 (2001; Supplements 2002-2008) Documentation of the Threshold Limit Values and Biological Exposure Indices

ASTM INTERNATIONAL (ASTM)

ASTM A36/A36M (2014) Standard Specification for Carbon Structural Steel

ASTM C1196 (2014) Standard Test Method for In Situ

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Compressive Stress Within Solid Unit Masonry Esitmated Using Flatjack Measurements

ASTM C1197 (2014) Standard Test Method for In Situ Measurement of Masonry Deformability Properties Using the Flatjack Method

ASTM C1324 (2010) Standard Test Method for Examination and Analysis of Hardened Masonry Mortar

ASTM C1364 (2010b) Standard Specification for Architectural Cast Stone

ASTM C1489 (2015) Standard Specification for Lime Putty for Structural Purposes

ASTM C1531 (2015) Standard Test Methods for In Situ Measurement of Masonry Mortar Joint Shear Strength Index

ASTM C1601 (2014) Standard Test Method for Field Measurement of Water Penetration of Masonry Wall Surfaces

ASTM C170/C170M (2015) Standard Test Method for Compressive Strength of Dimension Stone

ASTM C1713 (2012) Standard Specification for Mortars for the Repair of Historic Masonry

ASTM C207 (2006; R 2011) Standard Specification for Hydrated Lime for Masonry Purposes

ASTM C216 (2015) Facing Brick (Solid Masonry Units Made from Clay or Shale)

ASTM C34 (2013) Structural Clay Load-Bearing Wall Tile

ASTM C67 (2014) Standard Test Methods for Sampling and Testing Brick and Structural Clay Tile

ASTM C926 (2015b) Application of Portland Cement-Based Plaster

ASTM E2260 (2012) Standard Guide for Repointing (Tuckpointing) Historic Masonry

ASTM E2659 (2015) Standard Practice for Certificate Programs

ASTM E96/E96M (2014) Standard Test Methods for Water Vapor Transmission of Materials

NATIONAL PARK SERVICE (NPS)

NPS Hist Prop (1995) National Standards for the

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Treatment of Historic Properties with Guidelines for Preserving, Rehabilitating, Restoring, and Reconstructing Historic Buildings

NPS TPS Brief 1 (2000) Assessing Cleaning and Water-Repellent Treatments for Historic Masonry Buildings

NPS TPS Brief 2 (1998) Repointing Mortar Joints in Historic Masonry Buildings

THE MASONRY SOCIETY (TMS)

TMS MSJC (2011) Masonry Standard Joint Committee's (MSJC) Book - Building Code Requirements and Specification for Masonry Structures, Containing TMS 402/ACI 530/ASCE 5, TMS 602/ACI 530.1/ASCE 6, and Companion Commentaries

U.S. GENERAL SERVICES ADMINISTRATION (GSA)

GSA HPTP 07656-01 Installing Lead Stone Flashing to Protect Masonry Joints

1.2 DEFINITIONS

Terms are defined below as applicable to this project.

1.2.1 Aggregates

The sand component of mortar.

1.2.2 Biocides

A chemical treatment that inhibits, deters, or controls organic growth.

Such growth is typically removed by cleaning following biocide treatment..

1.2.3 Binder

The component of mortar that binds together the aggregate particles into a cohesive material.

1.2.4 Dispersed Lime Crack Injection

A repair method in which dispersed lime material is injected into small cracks ranging in width from hairline to 3.2 mm 1/8 in by use of needle or syringe.

1.2.5 Consolidant

A chemical product meant to strengthen loose or deteriorated stone.

1.2.6 Dutchman

A repair method in which deteriorated stone is removed in part and replaced with salvaged, harvested or new stone to make a seamless patch.

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1.2.7 Harvested

Units removed from inconspicuous areas of the building.

1.2.8 In situ

A term referencing a repair procedure in which the masonry units and mortar remain in place and are repaired without removal from the wall system

1.2.9 Joint Sealant

A flexible, chemical product that is used to create a weather-tight seal at the boundary of masonry units with other units or dissimilar materials.

1.2.10 Lead Flashing

An extruded lead material that is inserted into joints to assist in precluding water entry into the masonry.

1.2.11 Lime Wash

A protective surface treatment comprised of calcium hydroxide particles in suspension in water, along with small amounts of calcium carbonate, silica particles and other minerals.

1.2.12 Mockup

Specific area on the building approved by Contracting Officer to demonstrate the contractor's ability to apply, match and install specified materials.

1.2.13 Mortar

A mixture of binders, aggregates, and pigments used for reconstruction, repointing or stucco applications.

1.2.14 New Elements

New, non-historic materials added to masonry structures to aid in their ability to resist loads (typically seismic) or to resist water infiltration.

1.2.15 Patch

The use of substitute repair materials to treat damaged or deteriorated masonry units in situ.

1.2.16 Remediate

An intervention of a historic masonry structure and its component materials with the intent to maintain the original fabric to the greatest extent possible.

1.2.17 Remove

Specifically for historic masonry materials, the term means to detach an item from existing construction to the limits indicated.

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1.2.18 Replace

To reinstall an item in its original position (or where indicated) after remedial treatment, or to duplicate and reinstall an entire item with new material; with the original item serving as the pattern for creating the duplicate.

1.2.19 Repoint

To remove existing mortar joints to the specified depth and replace with a mortar that matches in color, texture, and performance with water vapor transmission, bond, hardness, and flexibility compatible with original mortar, as assessed in accordance with ASTM C1713.

1.2.20 Retool

A repair method in which a chisel is used to re-create the surrounding stone texture finish by removing loose pieces of stone.

1.2.21 Stucco

A mixture of binders and aggregates, sometimes including animal hair or fibers used for the repair treatment of existing stucco.

1.2.22 Surface Treatment

The application of traditional materials or contemporary chemical products to the surface of masonry to provide protection to the masonry units and mortar and/or reduce water infiltration.

1.2.23 Test Panel

Specific area on the building approved by the Contracting Officer to demonstrate individual applicator competency and workmanship proficiency prior to the start of restoration work.

1.2.24 Tuckpointing

Often called skim-coating, an American practice of surface repairing mortar joints without the required removal of existing deteriorated mortar beneath. This practice is not recommended for mortar joint repair work on historic masonry. There is also an acceptable British form of tuckpointing practice that involves careful thin penciling of smaller joints within larger ones to give the wall the appearance of an ashlar finish.

1.2.25 Water Repellent

A surface-applied chemcial intended to reduce liquid water entry into a masonry wall without significantly affecting the vapro transmission properties of the original material.

1.2.26 Wall System

A term used to address the fact that masonry structures are comprised of different materials but function holistically, requiring that all restoration and cleaning process take into account the implications of the treatment to the adjacent materials and the building as a whole.

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1.2.27 Masonry Treatment Requirement (MTR)

Defined treatments that are required by the specification (contract) documents for project specific repairs to masonry.

1.2.28 Saturated Surface Dry (SSD)

Condition of the wall surface after water has been applied sufficient to saturate more than the surface, then allowed to dry until the surface is dry but the body of the masonry still has moisture.

1.3 ADMINISTRATIVE REQUIREMENTS

1.3.1 Pre-Installation Meeting

Prior to beginning the work of this Section, convene a meeting with the Contracting Officer's Representative(s) to review the requirements of the Quality Control Plan, Project Training Program, installation procedures, location of required mockup areas, and all job conditions and processes.

All subcontracting firms involved with this work shall participate in this meeting.

1.4 SUBMITTALS

NOTE: Review submittal description (SD) definitions in Section 01 33 00 SUBMITTAL PROCEDURES and edit the following list to reflect only the submittals required for the project.

The Guide Specification technical editors have designated those items that require Government approval, due to their complexity or criticality, with a "G." Generally, other submittal items can be reviewed by the Contractor's Quality Control System. Only add a “G” to an item, if the submittal is sufficiently important or complex in context of the project.

For submittals requiring Government approval on Army projects, a code of up to three characters within the submittal tags may be used following the "G" designation to indicate the approving authority.

Codes for Army projects using the Resident Management System (RMS) are: "AE" for Architect-Engineer; "DO" for District Office (Engineering Division or other organization in the District Office); "AO" for Area Office; "RO" for Resident Office; and "PO" for Project Office. Codes following the "G" typically are not used for Navy, Air Force, and NASA projects.

An "S" following a submittal item indicates that the submittal is required for the Sustainability Notebook to fulfill federally mandated sustainable requirements in accordance with Section 01 33 29

SUSTAINABILITY REPORTING.

Choose the first bracketed item for Navy, Air Force

SECTION 04 01 20.70 Page 11 and NASA projects, or choose the second bracketed item for Army projects.

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for [Contractor Quality Control approval.] [information only. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government.] Submittals with an "S" are for inclusion in the Sustainability Notebook, in conformance to Section 01 33 29 SUSTAINABILITY REPORTING. Submit the following in accordance with Section 01 33 00

SUBMITTAL PROCEDURES:

SD-01 Preconstruction Submittals

Quality Control Plan; G [, [_____]] Project Training Program; G [, [_____]] Qualifications; G [, [_____]]

SD-02 Shop Drawings; G [, [_____]]

Photographic Documentation Structural Upgrades; G [, [_____]]

SD-03 Product Data

Qualifications Cleaning and Restoration Methods; G [, [_____]] Cleaning Materials; G [, [_____]] Biocides Replacement Mortar And Stucco; G [, [____]] Mortar Mix; G [, [_____]] Water Repellents Infiltration; G [, [_____]] Stone Consolidants; G [, [_____]]

SD-04 Samples

Mock-ups; G [, [_____]]

SD-05 Design Data

Calculations for Structural Upgrades; G [, [_____]]

SD-06 Test Reports

Testing and Matching Existing Sealants for Asbestos and PCBs

SD-07 Certificates

Repair Materials

1.5 QUALITY CONTROL

1.5.1 Quality Control Plan

[Prior to beginning restoration and cleaning work, submit a written Quality Control Plan.][Include a separate section in the overall project Quality Control Plan specifically addressing this restoration and cleaning work.]

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Do not proceed without written approval of the Quality Control Plan. At a minimum, include the following items in the Quality Control Plan:

a. Describe methods of dust containment during the work specific to the work of this section.

b. Describe the methods of protecting surrounding masonry, windows, doors, roof, and building trim as well as surrounding landscape. Provide drawings of protection when requested.

c. Describe the work procedures, materials, and tools the contractor proposes to use for each Masonry Treatment Requirement (MTR) specified.

d. Describe the sequence of each MTR.

e. Describe how each MTR sequence and the overall construction schedule changes with weather variations and how completed work will be protected.

f. Describe the methods for surveying original layout and collecting datum points and plumb lines for rebuilding masonry.

g. Describe the methods for shoring and providing a safe working environment.

h. Describe the methods for select deconstruction of individual masonry units and tools/methods for cleaning the masonry for reuse.

i. Describe the method and approach to mortar joint removal.

j. Describe the method and approach for assuring repair material compatibility with original materials.

k. Describe the method and approach to cleaning mortar, coating, smears and old patching materials from the masonry surfaces.

l. Describe, in detail, the procedures relating to techniques and tools proposed for masonry matching.

m. Describe the complete masonry removal and matching procedures; include equipment, approach, length of time the masonry will be out of the wall, documentation on mapping the location, and where (on-site or in shop) the masonry units will be repaired.

n. Describe the procedure for matching of different colors at different locations.

o. Describe the procedure for mixing and matching of repair materials.

p. Describe the methods and system by which the use of reclaimed masonry units can be utilized.

q. Describe the methods for setting masonry back into its original position and maintaining the original bond patterns and joint width.

r. Describe the methods of transition points where replacement/preservation work will meet the original historic work.

s. Describe the on-site project training program. Provide the opportunity

SECTION 04 01 20.70 Page 13 for workers to be trained in each masonry treatment requirement (MTR) as work proceeds.

1.5.2 Qualifications

1.5.2.1 Historic Masonry Consultant

a. Secure the services of a historic masonry consultant with a minimum of 10 years experience applying NPS Hist Prop as they relate to the work in this section.

b. Submit a resume that describes five relevant projects within that period and include how NPS Hist Prop was applied to the work of similar scope and scale and what jurisdiction or agency was involved in approving the work..

c. The consultant's services include:

(1) Investigating the condition of the masonr materials and mortar.

(2) Arranging for material analysis in the laboratory

(3) Recommending appropriate cleaning methods and materials

(4) Recommending restoration options.

(5) Providing project specific specifications.

(6) Providing an on-site training program.

(7) Providing quality control services during construction.

(8) Recommending appropriate repair and restoration materials.

1.5.2.2 Masonry Firm

a. The firm performing the masonry work shall have a minimum of five years experience on relevant projects.

b. The firm shall have completed work similar in material, design, and extent to that indicated for this Project and shall demonstrate a record of successful in-service performance.

c. Proven implementation of NPS Hist Prop and related Preservation Briefs are required.

d. Submit a resume that describes the required experience.

1.5.2.3 Field Supervisor

Retain an experienced full-time supervisor on the project site at all times when masonry restoration is in progress. A single individual shall be responsible for supervising the historic masonry restoration work throughout the duration of the project.

Submit a resume that describes the required experience.

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1.5.2.4 Masonry Applicator

a. Employ craftspeople who are experienced with and specialize in restoration work of the types they will be performing.

b. All masonry restoration treatments must be performed by a craftsperson that is familiar with historic masonry construction and has worked on historic masonry projects for at least five years.

c. Only skilled technicians who are familiar and experienced with the materials and methods specified may be used.

d. Submit resumes for all historic masonry applicators, demonstrating the required experience.

1.5.3 Project Training Definition and Use

In addition to five years demonstrable experience on masonry restoration projects, offer workers project training certificate(s) within the framework of ASTM E2659. Project training certificates are earned by individual workers and issued with the understanding that they are for limited time use, enforceable only to this specific project and for a specific MTR. It is not necessary, nor a requirement of this specification, that all restoration workers obtain all project training certificates offered. Rather it is desirable that workers be trained for each project specific task they will perform to ensure the highest quality results from the cleaning and restoration program.

1.5.4 Mortar Analyst

Laboratory mortar analysis equipment should be operated by and results analyzed by trained personnel experienced with analysis of historic masonry mortar.

1.5.5 Documentation

Submit digital photographic documentation of the all phases of masonry restoration, including prior to the start of restoration work.

Provide thorough photo documentation of the project and project details and targeted areas.

1.5.6 Cleaning and Restoration Methods

1.5.6.1 General Procedure

a. Submit the cleaning and restoration methods, and materials selected for a specific structure for approval before work starts.

b. Take into account the total construction system of the building to be worked upon, including different masonry and mortar materials, as well as non-masonry elements which may be affected by the work.

c. Utilize mockups to identify the appropriate cleaning and restoration treatment and materials and set the standard for each project task.

d. Demonstrate the correct execution of the approved cleaning and restoration methods and materials during the on-site workmanship training program within the framework of ASTM E2659.

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1.5.6.2 Cleaning Products and Procedures

a. General Cleaning Requirements

(1) Establish cleaning products and procedures during the mockup process.

(2) Select the least aggressive method used to achieve the desired level of cleanliness.

(3) Where chemical products are selected for cleaning, use them in accordance with the manufacturer's instructions.

b. Cleaning Mock-Ups

(1) Demonstrate the materials, equipment, and methods to be used in cleaning in a test section approximately 1 meter by 1 meter 3 feet by 3 feet.

(2) Locate test patches in inconspicuous areas of the building. The areas tested are subject to approval by the Contracting Officer.

The areas tested shall exhibit soiling characteristics representative of those larger areas to be cleaned.

(3) Adjust the cleaning process as required and the test section rerun until an acceptable process is obtained.

(4) Conduct tests on areas to be stripped of paint.

(5) Allow tested areas to dry before a determination is made on the effectiveness of a particular treatment.

1.5.7 Masonry Restoration Products and Procedures

a. General Restoration Requirements

(1) Do not use masonry or mortar in the work until the mock-ups and the represented material and workmanship have been submitted and approved.

(2) Demonstrate the methods and quality of workmanship to be performed in each masonry treatment requirement (MTR). Provide a mock-up for each MTR indicated.

b. General Restoration Mock-Up Requirements

(1) Throughout restoration, retain approved mock-up panels in undisturbed condition, suitably marked, as a standard for judging completed work.

(2) Review manufacturer's product data sheets to determine suitability of each product for each surface.

(3) Apply products using manufacturer-approved application methods, determining actual requirements for application..

(4) Obtain approval as to the preservation treatment approach, design, and workmanship to include, but not limited to the verification of

SECTION 04 01 20.70 Page 16 all material applications and finishes as specified to the requirements of color, texture, profiles, and finishes before proceeding with work.

(5) Mock-ups: May be performed on inconspicuous sections of actual construction under the same weather conditions expected the remainder of the work.

(a) Location and number as directed[, but no more than [_____]].

(b) Size: 1 meter by 1 meter 3 feet by 3 feet or as appropriate for the repair specified.

(c) Repair unacceptable work.

c. Restoration Mock-Ups

(1) Repointing: Repoint mortar joints, minimum acceptable mock up dimensions: twelve feet in length - 2/3 horizontal joints and 1/3 vertical joints. Demonstrate method for cutting out mortar joints, preparing wall for repointing, mixing mortar, installing mortar and curing the mortar. Prepare and place repointing mortar in accordance with NPS TPS Brief 2 and in compliance with NPS Hist Prop .

(2) Retooling Stone Masonry In situ: Demonstrate treatment technique and methods to retool three deteriorated stone faces in situ in all known historic profile textures identified.

NOTE: Common historic finish textures include, but are not limited to, corduroy and point chisel finishes.

(3) Masonry Removal and Replacement: Fully remove masonry and replace to specified dimensions and texture. Select size of masonry units representing typical conditions. Return one masonry unit to same location, set to surrounding profile joint width and bond pattern. Set masonry unit using specified mortar. Confirm with Contracting Officer's Representative that the replacement masonry units meet specification requirements for matching and that sufficient quantity required for the work have been identified.

Leave one stone dry-set into opening set on wood shims for evaluation and approval of preparation conditions.

(4) Repair Material

(a) Patching: Apply repair material on at least two masonry units for repair. Include one masonry unit on which to demonstrate proficiency in removing previous patching material and repairing with new substitute repair material. Include the removal of metal anchors at two locations and fill in the holes with repair material on the second masonry unit (where applicable).

(b) Dutchman: Undertake dutchman repairs in two locations, including one that is only cut and prepared for application.

Demonstrate the quality of the stone insert, as well as the workmanship and techniques to be performed in the dutchman

SECTION 04 01 20.70 Page 17 repairs. Do not proceed with other dutchman repairs until the technique has been approved.

(5) Crack Repair: Repair one crack, 600 mm 2 feet in length, using mortar. Repair one crack, 600 mm 2 feet in length, using dispersed hydrated lime injection technique with appropriate repair material.

(6) Surface Treatments: Install a minimum 1.5 square meter 16 square foot mockup for each surface treatment on each substrate to be treated. For stucco, demonstrate the means for installing each coat; including mechanical support systems such as wood or metal lath. For water repellents and/or consolidants, demonstrate the equipment and installation procedure. Allow 48 hours for limewash applications to dry to their final color and appearance.

NOTE: Consideration of new elements on a historic structure should only be undertaken once the addition is approved by the Contracting Officer.

New accessories are intended to provide structural strengthening or facilitate weather protection.

(7) New Masonry Elements: Install new components in a manner demonstrating their final installation on the structure.

1.6 DELIVERY, STORAGE, AND HANDLING

a. Furnish cement in suitable bags used for packaging cements.

b. Provide packages with labeling that clearly defines contents, manufacturer, and batch identification.

c. Provide detergents, masonry cleaners, paint removers, solvents, epoxies and other chemicals used for masonry cleaning in sealed containers that legibly show the designated name, formula or specification number, quantity, date of manufacture, manufacturer's formulation number, manufacturer's directions including any warnings and special precautions, and name of manufacturer.

d. Store materials in weathertight structures which will protect all materials from moisture and contaminants.

e. Store accessories to avoid contamination and deterioration.

f. Do not use admixtures which have been in storage onsite for six months or longer, or which have been subjected to freezing, unless retested and proven to meet the specified requirements.

1.7 PROJECT/SITE CONDITIONS

1.7.1 Environmental Requirements

a. Do not place materials when weather conditions adversely affect the quality of the finished product.

b. Do not place masonry or mortar when the air or surface temperature is below 5 degrees C 40 degrees F in the shade and will remain so for at

SECTION 04 01 20.70 Page 18 least 48 hours after completion of the work. Heated enclosures may be used to overcome ambient weather restrictions, where such enclosures are feasible.

c. Do not place masonry or mortar when air or surface temperature is above 35 degrees C 90 degrees F with a wind speed above13 kilometers per hour 8 miles per hour and will remain so for at least 48 hours after completion of the work.

d. Do not place masonry or mortar when air or surface temperature is above 38 degrees C100 degrees F with or without wind and will remain so for at least 48 ours after completion of the work.

e. Do not product or place materials during periods of rain or other precipitation. Stop material placements, and protect all in-place material from exposure, during periods of rain or other precipitation.

f. Clean masonry surfaces when air temperatures are above 5 degrees C 40 degrees F and will remain so until masonry has dried out, but for not less than 7 days after completion of the work.

g. Do not perform work in wind conditions that may blow materials onto surfaces not intended to be treated.

1.7.2 Masonry Installation Requirements

a. Phase work during hot weather by performing work on the shady side(s) of the building during daylight hours and on the daylight side(s) of the building during cooler evening hours to prevent premature evaporation of the water from the mortar.

b. Do not use frozen materials or materials mixed or coated with ice or frost. Do not apply materials to frozen surfaces; allow complete thawing prior to installation.

c. Do not lower the freezing point of mortar by the use of admixtures or anti-freeze agents. Do not add chlorides or admixtures containing greater than 0.2 percent chlorides to the mortar, per TMS MSJC.

d. Prevent mortar from staining the face of the masonry or other exposed surfaces. Immediately remove mortar that comes in contact with such surfaces. Cover partially completed work when work is not in progress. Protect sills, ledges and projections from mortar droppings. Building damage resulting from work of this Section is the Contractor's responsibility. Restore damaged areas to the satisfaction of the Owner at no expense to the Owner. Do not apply products under conditions outside product manufacturer's requirements.

1.8 WARRANTY

1.8.1 Cleaning Warranty

Warrant cleaning procedures for a period of two years against harm to substrate (masonry and mortar) or to adjacent materials including, but not limited to: discoloration of substrate from improper procedures or usage, chemical damage from inadequate rinse procedures, and abrasive damage from improper procedures.

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1.8.2 Repair Warranty

Warrant repair procedures, including repointing, for a period of two years against: discoloration or mismatch of new mortar to adjacent original historic mortar, discoloration or damage to masonry from improper mortar clean-up, loss of bond between masonry and mortar, fracturing of masonry edges from improper mortar joint preparation procedures or improper mortar formulation, and occurrence of efflorescence from improper repair procedures.

PART 2 PRODUCTS

2.1 CLEANING MATERIALS

2.1.1 General Requirements

Selection of appropriate cleaning products requires a clear understanding of the masonry materials to be cleaned, a rationale for the cleaning, and an understanding of the anticipated level of cleanliness expected from the cleaning program. Overly aggressive cleaning methods and materials can cause subtle, long-term damage to masonry units. Use products that have a minimum 5 year performance record on relevant projects. Select the products predicated on long-term negative effects to the masonry rather than current level of cleanliness of the comparable structure.

2.1.2 Paint Removers

a. Provide chemical paint removers that are water soluble, low toxicity products, effective for removal of paint on masonry without altering, damaging, or discoloring the masonry surface.

b. Provide commercially available poulticing materials designed to adhere to and peel off paint without damaging the underlying masonry or project specific mixtures that include absorbent materials and cleaning solutions which can be demonstrated to do no harm to the masonry.

2.1.3 Chemical Cleaners

NOTE: Chemical cleaners range from acidic to alkaline in their chemcial makeup. Selected products must be suitable for the type of masonry units to be cleaned.

a. Provide commercially available products that have a proven record of cleaning masonry without altering, damaging or discoloring the masonry units, mortar or surrounding materials.

b. Provide the associated pre and post treatment material to neutralize the long term effects of the chemicals.

2.1.4 Biocides

Provide commercially available biocides with accompanying product literature containing information on the product as well as the expected service life of the material and any detrimental effects it may have on the masonry or mortar.

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2.1.5 Liquid Strippable Masking Agent

Provide manufacturer's standard liquid, film-forming, strippable masking material for protecting glass, metal, and polished stone surfaces from the damaging effect of acidic and alkaline masonry cleaners.

2.1.6 Cleaning Implements

Furnish brushes that contain natural or nylon fiber bristles only. Do not use metallic wire brushes. Scrapers and application paddles shall be made of wood with rounded edges. Metallic tools are not permitted.

2.1.7 Water

NOTE: Filtering and neutralizing pH is rarely conducted for masonry cleaning, except for statues or museum pieces.

Obtain potable water from a local source. [Filter to remove minerals resulting in a neutral pH, prior to application.]

2.2 REPAIR MATERIALS

NOTE: Use materials, physical and chemical properties, and composition of masonry and mortar in renovation work that match the original existing masonry and mortar to be repaired, unless samples and testing determine that existing mixtures and materials are faulty or nonperforming. Masonry materials used for repair and renovation shall match the original existing historic materials as closely as possible in composition, color, texture, strength, size, finishing and porosity. Refer to ASTM C1713 for matching mortar.

2.2.1 General

Use repair materials of one type and from one source, when used in repair treatments that will have surfaces exposed in the finished structure.

2.2.2 Mortar and Stucco

NOTE: Mortar types L and K are not included in ASTM C270. Type L mortar uses only hydrated lime or lime putty as binder. Type K mortar has typical proportions in the range of 1 part cement, 2 to 3 parts lime, and 2 1/4 to 3 times the combined cement and lime components as sand.

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2.2.2.1 Testing and Matching

a. Take test specimens of existing mortar and stucco from a sound and intact representative portion of the structure, at locations [indicated][ or ][by the Contracting Officer's Representative] and assess in accordance with ASTM C1713 and ASTM C1324.

b. Subject a part of the historic mortar sample to petrographic examination and differential thermal analysis, or X-ray diffraction, or analytical chemistry to determine the binder components.

c. Aggregate Analysis

(1) Separate aggregate of the mortar sample from the binder [by taking the crushed mortar sample and either gently blowing away the fine binder material, placing the crushed sample in a centrifuge, or chemically separating the aggregate from the binder].

(2) Rinse the separated aggregate clean with water and dry. [Examine the aggregate with a magnifying glass, and record the component materials as to range of materials, sizes, colors, as well as the presence of other materials.]

(3) Perform sand analysis using a sieve analysis of the aggregate as part of the ASTM C1324 process.

d. Match the replacement mortar and stucco to the original existing material in color, texture and tooling.

2.2.2.2 Replacement Mortar and Stucco

Provide replacement mortar and stucco that will:

a. Coexist with the old in a sympathetic, supportive and, if necessary, sacrificial capacity.

b. Have greater vapor permeability and be softer (measured in compressive strength) than the masonry units.

(1) Measure water vapor transmission in accordance with ASTM E96/E96M.

(2) Prepare ASTM E96/E96M water vapor transmission specimens with thickness similar to that expected in service, or a maximum of 13 mm 1/2 inch, whichever is thinner.

c. Be as vapor permeable, and as soft, or softer, (measured in compressive strength) than the existing historic mortar or stucco.

2.2.2.3 Binder Content

NOTE: Historic mortars can represent four different binder types, or combination of them, depending on the time period of construction. A building constructed in the early 1800s is likely built with a straight lime putty binder type because the discovery of natural cement binder types had not occurred until the early 1820s. A building constructed in 1940 might be built with portland

SECTION 04 01 20.70 Page 22 cement (1871) and hydrated lime (1930s). The historic binder types include: non-hydraulic lime (fat lime, lime putty or hydrated lime); hydraulic lime (feebly, NHL 2, moderately, NHL 3.5, and imminently, NHL 5.0); natural cement; and portland cement. The binder types are all derived from limestone. Each successive type is fired at higher temperatures in a kiln to the point of vitrification or liquid phase (1204-1540 degrees C2200-2800 degrees F) when Portland cement is developed. Lime can be slaked into a hydrate powder or putty form by adding water due to the lower firing temperatures ( 900-1093 degrees C1650-2000 degrees F), while cement products must be crushed mechanically into a powder form before use. Each binder type has its own unique performance properties in relation to historic masonry units and the building wall design. A mortar formula made from lime putty (low compressive strength) will accommodate building movement in load-bearing masonry much more effectively than a portland cement formula of much higher compressive strength. Identify performance characteristics of the replacement mortar carefully based upon evaluation of the existing historic mortar.

Provide binder type or mixture of mortar (and stucco) with a cement, lime, or combination thereof consistent with the original existing mortar (and stucco) content in order to provide uniform durability, weathering characteristics, and the same, or better, life-cycle performance expectations.

2.2.2.4 Repointing Mortar

NOTE: If mortar testing is performed prior to project bidding and the compatible mortar type is known, select from the following choices.

Otherwise, delete the following paragraph and allow mortar to be determined by the above described testing.

[Repointing mortar shall be pre-blended in single containers in a factory-controlled environment.][Repointing mortar may be site mixed, Type S, Type N, Type L, Type O and Type K.][Use lime for repointing mortar that conforms to ASTM C207, Type S, or ASTM C1489 or unless otherwise specified.]

2.2.2.5 Admixtures

Do not use admixtures in the mortar or stucco unless specifically approved in writing by the Contracting Officer.

2.2.3 Crack Injection

NOTE: Dispersed hydrated lime (specified herein) is suitable for injection of cracks up to 3.2 mm1/8 inch

SECTION 04 01 20.70 Page 23 wide for architectural purposes (sealing, restoring appearance, preventing moisture infiltration) but has low bond and is not the best material for structural repairs. Masonry injection grouts (not specified herein) may be more suitable for structural repairs.

a. Comply with the dispersed hydrated lime manufacturer's written instructions.

b. Inject cracks that are no greater than 3 mm 1/8 inch in width and masonry is soundly bonded but cracked.

c. Inject the full length of the cracks unless specifically instructed otherwise.

2.2.4 Replacement Masonry Materials

2.2.4.1 Clay Brick

a. Provide replacement brick matching color, shape, size, texture, appearance, and thermal expansion properties of the existing historic brick.

b. Test brick in comparison to the original existing historic brick using

ASTM C67.

c. Do not use reclaimed brick unless approved by Contracting Officer.

d. Provide brick meeting the requirements of ASTM C216 Grade SW, including a rating of "not effloresced", unless otherwise specified.

2.2.4.2 Stone

a. Provide replacement sotne matching type, color, shape, size, texture, finish-profile, and compressive strength of the existing historic stone units.

b. Test replacement stone in comparison to the existing historic stone using ASTM C170/C170M.

2.2.4.3 Terra Cotta

a. Provide replacement terra cotta matching color, shape, size, texture and finish-profile of the existing historic terra cotta units.

b. Test replacement terra cotta in comparison to the existing historic terra cotta using ASTM C34.

2.2.4.4 Architectural Precast Stone

a. Provide replacement architectural precast stone matching color, shape, size, texture and finish-profile of the existing historic architectural precast stone units.

b. Test replacement architectural precast stone in comparison to the existing historic architectural precast stone using ASTM C1364.

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2.2.5 Surface Treatments

2.2.5.1 General

Provide commercially available coatings with water vapor permeabillity of

0.98 or greater, as measured in accordance with ASTM E96/E96M, including silanes and siloxanes.

2.2.5.2 Consolidants

Provide commercially available consolidants designed to strengthen loose or deteriorated stone without damaging intact stone or reducing water vapor permeability below 0.98, as measured in accordance with ASTM E96/E96M.

2.2.5.3 Water Repellents

Provide commercially available water repellents designed to preclude water droplet entry into the masonry walls without reducing water vapor permeability below 0.98. as measured in accordance with ASTM E96/E96M.

2.2.6 Miscellaneous Materials

2.2.6.1 Cementitious Grout

Use cementitious grout, recommended by the manufacturer for the application, to bond steel anchors to masonry.

2.2.6.2 Metal Attachments

a. Provide threaded or deformed stainless steel anchors for spall repairs, size as indicated.

b. Provide other plates, angles, anchors, and embedments conforming to ASTM A36/A36M, prime painted with inorganic zinc primer.

2.2.6.3 Lead Flashing

Provide commercially available lead flashing conforming to GSA HPTP 07656-01 .

2.3 EQUIPMENT

2.3.1 Cleaning Equipment

Provide cleaning equipment that does not cause staining, erosion, marring, or other damage or changes in the appearance of the surfaces to be cleaned.

2.3.1.1 Sandblasting

Use of sandblasting equipment is not allowed for cleaning masonry surfaces.

2.3.1.2 Water Blasting

a. Provide water blasting equipment including a trailer-mounted water tank, pumps, high-pressure hose, wand with safety release cutoff control, nozzle, and auxiliary water re-supply equipment.

b. Do not operate the equipment at a pressure which will cause etching or other damage to the masonry surface or mortar joints. Operate the equipment at a discharge capacity of 0.38 to 3.0 MPa 55 to 400 psi and

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9.5 to 11.4 L/m 2.5 to 3 gpm for general surface cleaning operations.

c. Provide water tank and auxiliary re-supply equipment of sufficient capacity to permit continuous operations.

d. Provide protective covers and barriers as required to prevent over-spray onto adjacent surfaces.

2.3.1.3 Alternative Blasting Equipment

a. Alternative blasting methods require equipment designed to discharge sponges, walnut shells, ice, soda and other friable materials.

b. Operate equipment in accordance with manufacturer's recommendations and maintain in good working order.

c. Do not operate equipment at a pressure which will cause etching or other damage to the masonry surface or mortar joints.

d. Determine discharge capacity on a case by case basis during the mockup test panel demonstration and approval process.

e. Provide protective covers and barriers as required to prevent over-spray onto adjacent surfaces.

2.3.2 Spray Equipment

a. Provide spray equipment for chemical cleaners with low-pressure tanks or chemical pumps suitable for chemical cleaner indicated, and equipped with stainless steel, cone-shaped spray-tip.

b. Disperse water through a fan-shaped spray tip at an angle of not less than 15 degrees.

c. Deliver water at a pressure not greater than 3.0 MPa 400 psi and at a volume between 9.5 and 11.4 L/m 2.5 and 3 gpm.

d. Deliver heated water at flow rates indicated maintaining between 60 and 82 degrees C 140 and 180 degrees F.

2.3.3 Drilling Equipment

a. Use standard small, powered, handheld masonry drills, commonly used for drilling small holes in concrete and masonry to drill holes in masonry for patch anchors and other applications.

b. Use drills in rotary mode only. Do not use impact type drills.

2.3.4 Compressed Air Supplies

a. Use compressed air equipment that delivers clean, oil and moisture free compressed air at the surface to be cleaned. Use a minimum of two in-line air filters to remove oil and moisture from the air supply.

b. Test the compressed air supply during each shift for the presence of oil and moisture.

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2.3.5 Material Handling and Associated Equipment

2.3.5.1 Mixing, Transporting, and Placing Job Materials

a. Provide equipment used for mixing, transporting, placing, and confining masonry and mortar placements capable of satisfactorily mixing material and supporting uninterrupted placement operations.

b. Provide equipment used for mixing, conveying, and placing of materials that is clean, free of old materials and contaminants, and in conformance with material manufacturer's recommendations.

2.3.5.2 Associated Equipment

Provide associated equipment, such as mixer timing equipment, valves, pressure gauges, pressure hoses, other hardware, and tools, as required to ensure a continuous supply of material and operation control.

2.4 Mortar Mix

2.4.1 General

a. Proportion materials appropriately with regard to the effect of moisture content on the individual components (cement, sand and lime).

b. Batch materials using volumetric measurement devices and consistently consolidate the material in these devices to ensure the uniformity of the mortar. Do not batch by shovel counts.

2.4.2 Batching

a. Utilize a calibrated measuring device for batching Portland cement.

b. Utilize a calibrated measuring device for batching hydrated lime or lime putty.

c. Utilize a calibrated measuring device for…