TE-18 - UFGS 04 03 00 - Conservation for Period Masonry - 2017.pdf

USACE / NAVFAC / AFCEC / NASA UFGS- 04 03 00 ( November 2017) Pr epar i ng Act i v i t y: USACE Super sedi ng UFGS- 04 01 20. 70 ( November 2015)

UNI FI ED FACI LI TI ES GUI DE SPECI FI CATI ONS

Ref er ences ar e i n agr eement wi t h UMRL dat ed Jul y 2019

SECTION TABLE OF CONTENTS

DIVISION 04 - MASONRY

SECTION 04 03 00

CONSERVATION TREATMENT FOR PERIOD MASONRY

11/17

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

SECTION 04 03 00 Page 1

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

1.5.6.2.1 General Cleaning Requirements

1.5.6.2.2 Cleaning Mock-Ups

1.5.7 Masonry Restoration Products and Procedures

1.5.7.1 General Restoration Requirements

1.5.7.2 General Restoration Mock-Up Requirements

1.5.7.2.1 Mock-ups

1.5.7.3 Restoration Mock-Ups

1.5.7.3.1 Repointing

1.5.7.3.2 Retooling Stone Masonry In Situ

1.5.7.3.3 Masonry Removal and Replacement

1.5.7.3.4 Repair Material

1.5.7.3.4.1 Patching

1.5.7.3.4.2 Dutchman

1.5.7.3.5 Crack Repair

1.5.7.3.6 Surface Treatments

1.5.7.3.7 New Masonry Elements

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

SECTION 04 03 00 Page 2

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

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

SECTION 04 03 00 Page 3

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

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 03 00 Page 4

USACE / NAVFAC / AFCEC / NASA UFGS- 04 03 00 ( November 2017) Pr epar i ng Act i v i t y: USACE Super sedi ng UFGS- 04 01 20. 70 ( November 2015)

UNI FI ED FACI LI TI ES GUI DE SPECI FI CATI ONS

Ref er ences ar e i n agr eement wi t h UMRL dat ed Jul y 2019

SECTION 04 03 00

CONSERVATION TREATMENT FOR PERIOD MASONRY

11/17

NOTE: Thi s gui de speci f i cat i on cover s t he r equi r ement s f or r est or at i on and cl eani ng of masonr y i n hi st or i c st r uct ur es.

Adher e t o UFC 1-300-02 Uni f i ed Faci l i t i es Gui de Speci f i cat i ons ( UFGS) For mat St andar d when edi t i ng t hi s gui de speci f i cat i on or pr epar i ng new pr oj ect speci f i cat i on sect i ons. Edi t t hi s gui de speci f i cat i on f or pr oj ect speci f i c r equi r ement s by addi ng, del et i ng, or r evi s i ng t ext . For br acket ed i t ems, choose appl i cabl e i t em( s) or i nser t appr opr i at e i nf or mat i on.

Remove i nf or mat i on and r equi r ement s not r equi r ed i n r espect i ve pr oj ect , whet her or not br acket s ar e present.

Comment s, suggest i ons and r ecommended changes f or t hi s gui de speci f i cat i on ar e wel come and shoul d be submi t t ed as a Criteria Change Request (CCR) .

PART 1 GENERAL

NOTE: Wher e t he wor ds " as i ndi cat ed" ar e used, ensur e t hat s i zes, posi t i ons and ot her desi gnat ed i nf or mat i on ar e i ndi cat ed on t he desi gn dr awi ngs.

The f ol l owi ng publ i cat i ons, f r om t he Uni t ed St at es Depar t ment of t he I nt er i or - Nat i onal Par k Ser vi ce, pr ovi de usef ul gui dance i n t he r est or at i on of hi st or i c masonr y and may be i ncl uded as addenda t o t he speci f i cat i ons.

The Secr et ar y of t he I nt er i or ' s St andar ds f or t he Tr eat ment of Hi st or i c Pr oper t i es wi t h Gui del i nes f or Pr eser vi ng, Rehabi l i t at i ng, Rest or i ng, and Reconst r uct i ng Hi st or i c Bui l di ngs ( 1995) .

SECTION 04 03 00 Page 5

Pr eser vat i on Br i ef #1 - ( 2000) Assessi ng Cl eani ng and Wat er - Repel l ent Tr eat ment s f or Hi st or i c Masonr y Buildings

Pr eser vat i on Br i ef #2 - ( 1998) Repoi nt i ng Mor t ar Joi nt s i n Hi st or i c Br i ck Bui l di ngs

Pr eser vat i on Br i ef #6 - ( 1979) Danger s of Abr asi ve Cl eani ng t o Hi st or i c Bui l di ngs

Pr eser vat i on Br i ef #7 - ( 1979) The Pr eser vat i on of Hi st or i c Gl azed Ar chi t ect ur al Ter r a- Cot t a

Pr eser vat i on Br i ef #22 - ( 1990) The Pr eser vat i on and Repai r of Hi st or i c St ucco

Pr eser vat i on Br i ef #38 - ( 1995) Removi ng Gr af f i t i f r om Hi st or i c Masonr y

1.1 REFERENCES

NOTE: Thi s par agr aph i s used t o l i s t t he publ i cat i ons c i t ed i n t he t ext of t he gui de speci f i cat i on. The publ i cat i ons ar e r ef er r ed t o i n t he t ext by basi c desi gnat i on onl y and l i s t ed i n t hi s par agr aph by or gani zat i on, desi gnat i on, dat e, and t i t l e.

Use t he Ref er ence Wi zar d' s Check Ref er ence f eat ur e when you add a Ref er ence I dent i f i er ( RI D) out si de of t he Sect i on' s Ref er ence Ar t i c l e t o aut omat i cal l y pl ace t he r ef er ence i n t he Ref er ence Ar t i c l e. Al so use t he Ref er ence Wi zar d' s Check Ref er ence f eat ur e t o updat e t he i ssue dat es.

Ref er ences not used i n t he t ext wi l l aut omat i cal l y be del et ed f r om t hi s sect i on of t he pr oj ect speci f i cat i on when you choose t o r econci l e r ef er ences i n t he publ i sh pr i nt pr ocess.

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 (2015; Suppl 2002-2016) Documentation of the Threshold Limit Values and Biological Exposure Indices

ASTM INTERNATIONAL (ASTM)

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

ASTM C34 (2017) Standard Specification for

SECTION 04 03 00 Page 6

Structural Clay Loadbearing Wall Tile

ASTM C67/C67M (2018) Standard Test Methods for Sampling and Testing Brick and Structural Clay Tile

ASTM C170/C170M (2017) Standard Test Method for Compressive Strength of Dimension Stone

ASTM C207 (2018) Standard Specification for Hydrated Lime for Masonry Purposes

ASTM C216 (2017) Standard Specification for Facing Brick (Solid Masonry Units Made from Clay or Shale)

ASTM C926 (2018b) Standard Specification for Application of Portland Cement-Based Plaster

ASTM C1196 (2014) Standard Test Method for In Situ 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 (2015) Standard Test Method for Examination and Analysis of Hardened Masonry Mortar

ASTM C1364 (2018) 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 C1713 (2012) Standard Specification for Mortars for the Repair of Historic Masonry

ASTM E96/E96M (2016) Standard Test Methods for Water Vapor Transmission of Materials

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

ASTM E2659 (2018) Standard Practice for Certificate Programs

SECTION 04 03 00 Page 7

NATIONAL PARK SERVICE (NPS)

NPS Hist Prop (2017) National Standards for the 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 (2016) 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.

SECTION 04 03 00 Page 8

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.

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 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.

SECTION 04 03 00 Page 9

1.2.17 Remove

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

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

SECTION 04 03 00 Page 10 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.

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 must participate in this meeting.

1.4 SUBMITTALS

NOTE: Revi ew submi t t al descr i pt i on ( SD) def i ni t i ons i n Sect i on 01 33 00 SUBMI TTAL PROCEDURES and edi t t he f ol l owi ng l i s t t o r ef l ect onl y t he submi t t al s r equi r ed f or t he pr oj ect .

The Gui de Speci f i cat i on t echni cal edi t or s have desi gnat ed t hose i t ems t hat r equi r e Gover nment appr oval , due t o t hei r compl exi t y or cr i t i cal i t y, wi t h a " G. " Gener al l y, ot her submi t t al i t ems can be r evi ewed by t he Cont r act or ' s Qual i t y Cont r ol Syst em. Onl y add a “ G” t o an i t em, i f t he submi t t al i s suf f i c i ent l y i mpor t ant or compl ex i n cont ext of t he pr oj ect .

For submi t t al s r equi r i ng Gover nment appr oval on Ar my pr oj ect s, a code of up t o t hr ee char act er s wi t hi n t he submi t t al t ags may be used f ol l owi ng t he " G" desi gnat i on t o i ndi cat e t he appr ovi ng aut hor i t y.

Codes f or Ar my pr oj ect s usi ng t he Resi dent Management Syst em ( RMS) ar e: " AE" f or Ar chi t ect - Engi neer ; " DO" f or Di st r i ct Of f i ce ( Engi neer i ng Di v i s i on or ot her or gani zat i on i n t he Di st r i ct Of f i ce) ; " AO" f or Ar ea Of f i ce; " RO" f or Resi dent Of f i ce; and " PO" f or Pr oj ect Of f i ce. Codes f ol l owi ng t he " G" t ypi cal l y ar e not used f or Navy, Ai r For ce, and NASA pr oj ect s.

The " S" f ol l owi ng a submi t t al i t em i ndi cat es t hat t he submi t t al i s r equi r ed f or t he Sust ai nabi l i t y eNot ebook t o f ul f i l l f eder al l y mandat ed sust ai nabl e

SECTION 04 03 00 Page 11 r equi r ement s i n accor dance wi t h Sect i on 01 33 29 SUSTAI NABI LI TY REPORTI NG. Locat e t he " S" submi t t al under t he SD number t hat best descr i bes t he submi t t al i t em.

Choose t he f i r st br acket ed i t em f or Navy, Ai r For ce and NASA pr oj ect s, or choose t he second br acket ed i t em f or Ar my pr oj ect s.

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 eNotebook, 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[, [_____]]

SECTION 04 03 00 Page 12

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.] 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 proposed tools 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

SECTION 04 03 00 Page 13 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 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 masonry 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 must have a minimum of five years experience on relevant projects.

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

SECTION 04 03 00 Page 14 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 must be responsible for supervising the historic masonry restoration work throughout the duration of the project.

Submit a resume that describes the required experience.

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.

SECTION 04 03 00 Page 15

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.

1.5.6.2 Cleaning Products and Procedures

1.5.6.2.1 General Cleaning Requirements

a. Establish cleaning products and procedures during the mockup process.

b. Select the least aggressive method used to achieve the desired level of cleanliness.

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

1.5.6.2.2 Cleaning Mock-Ups

a. 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 .

b. Locate test patches in inconspicuous areas of the building. The areas tested are subject to approval by the Contracting Officer. The areas tested must exhibit soiling characteristics representative of those larger areas to be cleaned.

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

d. Conduct tests on areas to be stripped of paint.

e. 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

1.5.7.1 General Restoration Requirements

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

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

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1.5.7.2 General Restoration Mock-Up Requirements

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

b. Review manufacturer's product data sheets to determine suitability of each product for each surface.

c. Apply products using manufacturer-approved application methods, determining actual requirements for application.

d. Obtain approval as to the preservation treatment approach, design, and workmanship to include, but not limited to the verification of all material applications and finishes as specified to the requirements of color, texture, profiles, and finishes before proceeding with work.

1.5.7.2.1 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 m by 1 m 3 feet by 3 feet or as appropriate for the repair specified.

c. Repair unacceptable work.

1.5.7.3 Restoration Mock-Ups

1.5.7.3.1 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 .

1.5.7.3.2 Retooling Stone Masonry In Situ

NOTE: Common hi st or i c f i ni sh t ext ur es i ncl ude, but ar e not l i mi t ed t o, cor dur oy and poi nt chi sel finishes.

Demonstrate treatment technique and methods to retool three deteriorated stone faces in situ in all known historic profile textures identified.

1.5.7.3.3 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

SECTION 04 03 00 Page 17 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.

1.5.7.3.4 Repair Material

1.5.7.3.4.1 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).

1.5.7.3.4.2 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 repairs. Do not proceed with other dutchman repairs until the technique has been approved.

1.5.7.3.5 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.

1.5.7.3.6 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.

1.5.7.3.7 New Masonry Elements

NOTE: Consi der at i on of new el ement s on a hi st or i c st r uct ur e shoul d onl y be under t aken once t he addi t i on i s appr oved by t he Cont r act i ng Of f i cer .

New accessor i es ar e i nt ended t o pr ovi de st r uct ur al st r engt heni ng or f aci l i t at e weat her pr ot ect i on.

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

SECTION 04 03 00 Page 18 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 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 above 13 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 C 100 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

SECTION 04 03 00 Page 19 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.

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.

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2.1.3 Chemical Cleaners

NOTE: Chemi cal c l eaner s r ange f r om aci di c t o al kal i ne i n t hei r chemci al makeup. Sel ect ed pr oduct s must be sui t abl e f or t he t ype of masonr y uni t s t o be cl eaned.

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.

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. Use scrapers and application paddles made of wood with rounded edges. Metallic tools are not permitted.

2.1.7 Water

NOTE: Fi l t er i ng and neut r al i z i ng pH i s r ar el y conduct ed f or masonr y c l eani ng, except f or st at ues or museum pi eces.

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 mat er i al s, physi cal and chemi cal pr oper t i es, and composi t i on of masonr y and mor t ar i n r enovat i on wor k t hat mat ch t he or i gi nal exi st i ng masonr y and mor t ar t o be r epai r ed, unl ess sampl es and t est i ng det er mi ne t hat exi st i ng mi xt ur es and mat er i al s ar e f aul t y or nonper f or mi ng. Masonr y mat er i al s used f or r epai r and r enovat i on shal l mat ch t he or i gi nal exi st i ng hi st or i c mat er i al s as c l osel y as possi bl e i n composi t i on, col or , t ext ur e, SECTION 04 03 00 Page 21 st r engt h, s i ze, f i ni shi ng and por osi t y. Ref er t o ASTM C1713 f or mat chi ng mor t ar .

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: Mor t ar t ypes L and K ar e not i ncl uded i n ASTM C270. Type L mor t ar uses onl y hydr at ed l i me or l i me put t y as bi nder . Type K mor t ar has t ypi cal pr opor t i ons i n t he r ange of 1 par t cement , 2 t o 3 par t s l i me, and 2 1/ 4 t o 3 t i mes t he combi ned cement and l i me component s as sand.

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.

SECTION 04 03 00 Page 22

(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: Hi st or i c mor t ar s can r epr esent f our di f f er ent bi nder t ypes, or combi nat i on of t hem, dependi ng on t he t i me per i od of const r uct i on. A bui l di ng const r uct ed i n t he ear l y 1800s i s l i kel y bui l t wi t h a st r ai ght l i me put t y bi nder t ype because t he di scover y of nat ur al cement bi nder t ypes had not occur r ed unt i l t he ear l y 1820s. A bui l di ng const r uct ed i n 1940 mi ght be bui l t wi t h por t l and cement ( 1871) and hydr at ed l i me ( 1930s) . The hi st or i c bi nder t ypes i ncl ude: non- hydr aul i c l i me ( f at l i me, l i me put t y or hydr at ed l i me) ; hydr aul i c l i me ( f eebl y, NHL 2, moder at el y, NHL 3. 5, and i mmi nent l y, NHL 5. 0) ; nat ur al cement ; and por t l and cement . The bi nder t ypes ar e al l der i ved f r om l i mest one. Each successi ve t ype i s f i r ed at hi gher t emper at ur es i n a k i l n t o t he poi nt of v i t r i f i cat i on or l i qui d phase ( 1204- 1540 degr ees C2200-2800 degr ees F) when Por t l and cement i s devel oped. Li me can be sl aked i nt o a hydr at e powder or put t y f or m by addi ng wat er due t o t he l ower f i r i ng t emper at ur es ( 900- 1093 degr ees C1650- 2000 degr ees F) , whi l e cement pr oduct s must be cr ushed mechani cal l y i nt o a powder f or m bef or e use. Each bi nder t ype has i t s own uni que per f or mance pr oper t i es i n r el at i on t o hi st or i c masonr y uni t s and t he bui l di ng wal l desi gn. A mor t ar f or mul a made f r om l i me put t y ( l ow compr essi ve st r engt h) wi l l accommodat e bui l di ng movement i n l oad- bear i ng masonr y much mor e ef f ect i vel y t han a por t l and cement f or mul a of much hi gher compr essi ve st r engt h. I dent i f y per f or mance char act er i st i cs of t he r epl acement mor t ar car ef ul l y based upon eval uat i on of t he exi st i ng hi st or i c 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: I f mor t ar t est i ng i s per f or med pr i or t o pr oj ect bi ddi ng and t he compat i bl e mor t ar t ype i s known, sel ect f r om t he f ol l owi ng choi ces.

SECTION 04 03 00 Page 23

Ot her wi se, del et e t he f ol l owi ng par agr aph and al l ow mor t ar t o be det er mi ned by t he above descr i bed testing.

[Pre-blend repointing mortar 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: Di sper sed hydr at ed l i me ( speci f i ed her ei n) i s sui t abl e f or i nj ect i on of cr acks up t o 3. 2 mm1/ 8 i nch wi de f or ar chi t ect ur al pur poses ( seal i ng, r est or i ng appear ance, pr event i ng moi st ur e i nf i l t r at i on) but has l ow bond and i s not t he best mat er i al f or st r uct ur al r epai r s. Masonr y i nj ect i on gr out s ( not speci f i ed her ei n) may be mor e sui t abl e f or st r uct ur al r epai r s.

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/C67M.

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.

SECTION 04 03 00 Page 24

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.

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 .

SECTION 04 03 00 Page 25

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

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…