Supplemental_Specifications.pdf

Restoration of Stone Masonry Location: Grey Towers National Historic Site

Prepared: May 15, 2019

SECTION 01000

GENERAL INFORMATION & COORDINATION

PART 1: GENERAL:

1-1 COMMUNICATION PROCEDURE:

All official communications undertaken by the Contractor with the United States Forest Service regarding the work included in this contract will be addressed only to the Contracting Officer (CO), unless otherwise indicated in writing. Contact the Contracting Officer ____, at (000) 000-0000.

The CO shall also designate a Contracting Officer’s Representative (COR) at the work site and this shall be the Contractor’s on-site contact for verification on technical issues, scheduling the day to day activities, approvals and work accomplishments. The COR will not approve any substantive changes to the contract including eliminating or expanding work to include activities currently not in the scope of work nor does the COR have the authority to commit the government to additional costs.

1-2 PRE-BID SITE VISIT:

The Contracting Officer will provide the date for the pre-bid meeting. During this meeting the requirements of the contract requirements will be reviewed for the attending contractors by the Contracting Officer’s Representative (COR). The contractors will be permitted opportunities to ask questions about the specifications or site conditions affecting the work. The Contractor may visit the site prior to bidding, either before or after the pre-bid meeting but should not expect the COR to be available due to other work requirements. It is important and recommended that the potential bidders (contractors) who wish to understand these requirements bid attend the pre-bid meeting. The Contractor is responsible for field checking and verifying all measurements and site conditions prior to submitting a bid. For further information contact the CO.

1-3 PROJECT COMMENCEMENT:

After award to the successful bidder, the Contracting Officer (CO) shall be provide the contractor with a notice to proceed. The contractor shall then work with the COR and arrange the start date for mobilization to the work site. The contractor shall notify the COR and not begin work without the COR being on site.

1-4 EMERGENCY NOTIFICATION:

The Contractor shall report any and all incidents, accidents, and injuries that occur at a work site within the Grey Towers National Historic Site's boundaries to the COR, GTNHS safety coordinator, Becky Philpot (570-296-9679, or they can contact any Forest Service employee, or by calling the general phone number at (570) 296-9630.

1-5 PRESERVATION OF CULTURAL RESOURCES:

In the event that historic or cultural resources are to remain intact in the work area the contractor shall protect these features from damage at all times. If the contractor is unsure of which resources may be of historic or archeological significance when encountering unknown, underground features not previously identified, the contractor should inquire with the COR and he/she will provide information and direction to the contractor of the concerns or requirements in a reasonable time. Do not damage or proceed with work activities in that area without any authorization to do so from the COR. Any damages shall be reported to the COR.

1-6 PRESERVATION OF ARCHAEOLOGICAL AND HISTORICAL OBJECTS:

A. If any previously unidentified features of archaeological or historical significance are discovered, the CO shall have the right to stop the work until the significance of the finds can be determined. If any findings result in delays, or additional work for the contractor, he/she will be compensated by an equitable adjustment under the General Provisions of the Contract.

B. All items discovered, which in the opinion of the COR, have archaeological or historical significance, shall remain the property of the Government and shall be delivered to the COR or stored where directed by him/her.

C. Do not attempt to move historic objects or artifacts, contact COR to have them moved by the appropriate personnel.

1-7 PRESERVATION OF NATURAL FEATURES:

The Contractor is responsible for the condition of the work site and surrounding landscape. This responsibility includes the prevention of natural site damage and the subsequent repair or restoration to original condition of same species and or approved equal, at no additional cost to the Government.

The Contractor may not remove, damage, or destroy any trees, plants, or any other natural features without prior consultation and approval of the COR.

1-8 SITE ACCESS:

The Contractor is permitted full access to the designated area on the site during business hours (7a- 5p) and shall notify the COR of any planned changes a week in advance for approval. Working before or after the normal business hours, or on Saturday or Sunday, require special approval from the COR in writing.

1-9 CONTRACTUAL REQUIREMENTS:

A. Contractor shall inform COR of all work activities on site. The contractor and their subcontractors shall complete this work in a neat and orderly manner and in the quickest possible time without sacrificing quality required by the specifications. Work shall commence after award and within 4 weeks (30 days) of notice to proceed, unless otherwise instructed by the CO.

Ninety (90) calendar days is allowed for completion of the items listed in the base bid of this project.

B. During the course of demolition the contractor shall report to the Contracting Officer, in writing, any site conditions that exist which the contractor considers detrimental to the proper expedition of his work. The contractor shall, upon the request of the Contracting Officer, submit an itemized estimate for the work required to rectify the problem to the Contracting Officer. The itemized estimate shall include labor costs, equipment costs, material costs, and profit and overhead. All change orders, whether positive or negative adjustments to the original contract, are subject to negotiations between the contractor or designated representative, the Contracting Officer, and other concerned parties.

1-8 COMPLETION OF WORK:

A. Upon completion of this contract, the Contractor shall remove all apparatus, tools, equipment, surplus materials, rubbish, etc. and shall leave the premises clean, neat, orderly, and otherwise in a good condition.

1-9 FINAL INSPECTION AND ACCEPTANCE:

A. When all work described under this Contract has been completed and the clean-up performed, the

Contracting Officer shall make the final inspection on receipt of written notification by the Contractor. When any errors and omissions disclosed by the final inspection have been corrected, acceptance will be in writing. But, until acceptance the Contractor will be responsible for the work covered by this contract.

END OF SECTION

Prepared: August 25, 2019

SECTION 01110

GENERAL REQUIREMENTS OF CONTRACT

PART 1 GENERAL

1 .1 DESCRIPTION

A. All work will be performed under a single construction contract.

The work involved is the restoration of exterior masonry features at Grey Towers National Historic Site. These masonry landscape elements will include sections of boundary walls, corners, and replacement of coping stone. If funding allows other landscape features might be restored including additional portions of walls or other masonry features on the landscape.

Mortar failure caused by moisture penetration and freeze-thaw cycle and tree root penetration has caused deterioration of portions of the masonry structures on site necessitating disassembly and reconstruction. The work required will be the restoration of these stone features to their “documented” historic appearance. In some areas this appearance has been altered by limited modifications. Where these modifications have occurred in the past 40 years of federal ownership, the Forest Service will have that feature restored to their earlier appearance that will be explained during the pre-bid conference.

This appearance will be to match historic stone masonry from the particular historic period represented on the property (1930s – 1940s).

For an accurate understanding of the work to be required and the masonry elements included please refer to the information provided during the on-site pre-bid meeting or contact the Contracting Officer or the Contracting Officer’s Representative.

1 .2 LOCATION

A. Grey Towers National Historic Site is located at 151 Grey Towers Drive, Milford PA, 18337. Grey Towers Drive entrance is approximately a quarter mile west of the town of Milford PA on Old Owego Drive and 1 mile east of interstate 84. GPS point for entrance drive is: 41-328482, -74.814573.

1 .3 CONTRACTOR'S USE OF PREMISES

A. Construction Staging Area: Establishment of a staging area(s) should be requested in writing to the Forest Service for approval and shall include what the contractor would like placed/stored on the property and the duration. The location may vary according to the area of work. If needed provide temporary services might include a work trailer, portable toilets, electrical service or other utilities.

B. Keep staging area clean and organized daily. Assure that no construction debris or litter has an effect to the appearance of the government facility. Completely remove and restore area at completion of work to its original appearance. These requirements also apply to all Contractor's subcontractors, and even the employee’s personal effects.

Responsibility for maintaining the clean and neat appearance of the worksite, and the staging or parking area(s) are the Contractor’s.

C. Confine storage of materials to spaces provided by Forest Service or in temporary storage areas placed on site with permission of Forest Service Contracting Officer or COR (Contracting Officer’s Representative). This may occur in areas other than the staging area by permission of the COR.

D. Roadway Access: A county owned but township maintained roadway (Old Owego Turnpike) is a tertiary road running adjacent to this Forest Service property. A portion of the work is adjacent to that road and if closure from traffic is needed the contractor should contact those authorities. (COR shall provide that information on request). The contractor will be provided access to the work area on Forest Service owned driveways and land but should anticipate that normal access may not be always maintained through the project and delays or detours might be anticipated.

E. Hauling Restrictions: Comply with all legal load restrictions in the hauling of materials.

Load restrictions on the roadways have restrictions. Information regarding rules and regulations for vehicular traffic on roadways may be obtained from the COR. A special permit will not relieve Contractor of liability for damage which may result from moving of equipment.

F. Contractor shall, at all times, conduct his operations to ensure the least inconvenience or limitations to the public or Forest Service staff. If needed for the performance of work closing off areas will be permitted, and may be required for safety reasons, upon specific written approval of Contracting Officer.

G. Preservation of Natural Features: Confine all operations to work limits of the project.

Prevent damage to natural surroundings or waterways. Restore damaged areas, repairing or replacing damaged trees and plants, at no additional expense to the Government.

1. Provide temporary barriers to protect existing trees and plants and root zones to drip-line.

2. Do not remove, injure, or destroy trees or other plants without prior approval.

Consult with Contracting Officer or COR to agree on the methods for removing roots and branches that interfere with construction.

3. Some plant materials could be required by the nature of the work (roots, vines, etc) Grey Towers has a horticulturist who will be consulted for direction on tree and plant issues, their removal if the COR and horticulturist determines it is necessary to execute removal and what methods would be acceptable.

4. Do not fasten and materials (lumber, hardware, ropes, cables, or guys to existing trees or park equipment without consulting and receiving guidance from the COR.

5. Carefully supervise excavating, grading, filling, and other construction operations near trees to prevent damage unless previously identified for removal.

6. Restore land areas disturbed by contractor/subcontractors activities. Roto-till existing soil that was compacted during work activities to 6” depth. Secure, purchase & place approved topsoil to 2” depth, amend with organic compost and reseed with provided grass seed mixture, and apply turf fertilizer, straw mulch and water daily or as required by horticulturist. Recommended local source for grass seed mixture: Cerbo’s Hampten Nursery, 973 579 5518.

28% Kentucky Bluegrass 28% Creeping Red Fescue 22% Chewing Fescue 22% Oasis Perennial Rye

H. Existing Utilities: Notify Contracting Officer and utility companies of proposed locations and times for excavation.

1. Contractor shall be responsible for locating and preventing damage to known utilities. If damage to this known utility occurs during construction because of neglect, or inattention to the contractor, his subcontractors, or his representatives, to their actions or activities on site, the contractor shall repair utility at no additional expense to the Government.

2. If damage occurs to an unknown utility due to lack of inquiry or neglect of the contractor, his subcontractors, or his representatives, the contractor shall repair utility and the government shall determine financial responsibly as determined by the Contracting Officer, and an equitable adjustment will be made in accordance with the Changes clause of the contract.

Interruption of Existing Utility Service: No interruption is expected in this contract. In the event of a utility system IS encountered and requiring an interruption of service the contractor will cooperate with the government in resolving the issue.

1 .4 SPECIAL CONSTRUCTION REQUIREMENTS

A. The contractor shall provide a schedule that provides a sequencing of work to the Forest Service prior to beginning any work on site. This schedule will be adjusted and then provided to the Forest Service as work progresses and changes are made to accommodate issues or conditions that effect the original plan. Any uncontrollable effects on schedule (unusual or prolonged inclement weather conditions) that are not normal for the climate/region may delay completion of work plan on time. Please submit concerns to COR as soon as the effect is apparent on the work for a negotiated extension with the CO.

B. The normal work schedule shall be regular business hours – Monday through Friday, 7am – 5 pm. Early start and late finish of work activities and any weekend work performed on site needs prior approval by the CO or COR Submit a request at least 48 hours prior to the start time of the extension requested.

C. Holiday Work Restrictions: No on-site work shall be performed on government holidays without prior written approval being requested 48 hours in advance. (i.e., Memorial Day, July 4, Labor Day, Columbus Day) unless otherwise directed by the Contracting Officer.

D. A weekly coordination meeting may be required between the contractor, his subcontractors and the Forest Service. This meeting will be short in duration but will provide the opportunity to prevent delays or access problems for the contractor, the Forest Service or the visiting public. Day or the week and time of day will be provided at the pre-construction meeting after award of the contract.

1 .5 FIELD VERIFICATION

A. Field verify all new and existing dimensions affecting the work of this contract before ordering products.

1 .6 CONSTRUCTION MATERIALS

A. All other materials, including mortar materials, matching stone, masonry sand, or other aggregates, shall be Contractor-furnished from outside Grey Towers National Historic Site. There may be some materials available for use by the contractor which can be negotiated for use with the CO & COR. Please submit a proposal to the COR if their use is desired.

PART 2 PRODUCTS [NOT USED]

PART 3 EXECUTION [NOT USED]

PART 4 MEASUREMENT AND PAYMENT

4 .1 SUMMARY

A. Payment will be included in the bid item to which this work relates.

Prepared: Aug 23, 2019

SECTION 02010

RELATED SITE WORK

PART 1: GENERAL:

1-1 DESCRIPTION: The purpose of this section involves the conditions and special requirements on and near the work site(s).

1-2 WORK: The work consists of site work related to the demolition and removal/disposal of the identified material(s), and their components, clearing, excavation, fill or backfill operations, rough grading, and reinstallation of gravel trail adjacent to boundary walls.

1-3 QUALITY ASSURANCE:

A. Comply with local codes and regulations.

B. References: Comply with referenced standards as listed in the specifications.

C. Fees and permits: Permits required to accomplish the work of this contract shall be secured and paid for by contractor, except where identified as having been secured by the US Forest Service. Note: A portion of the work is near and crosses over the Vantine Brook, a tributary of the Sawkill Creek. A permit could be required to work near or traversing over the waterway.

D. Materials: All fill and backfill material shall comply with state & local requirements and specifications.

1-4 DRAWINGS: Site drawings or sketches shall be provided where necessary. Bidders shall visit the site to verify all conditions and dimensions having an effect upon site preparation, excavation and construction prior to submitting their bid.

1-5 SITE CONDITIONS: Special site conditions may exist at particular demolition sites which should be considered in the evaluation and execution of the project. These may include; stabilization of existing features, wetlands, waterways and drainage, vehicular access, temporary road closures, impacts to trails, etc.

1-6 ARCHAEOLOGICAL FEATURES: The construction area has been examined/tested for archaeological sensitivity. Testing was cursory in nature and therefore archeological resources may still which remain unknown. As a result the contractor will exercise caution during site excavation. The Contracting Officer shall be given two weeks advance notice, in writing, prior

Prepared: Aug 23, 2019 to beginning any un-scheduled excavation below the ground surface to allow time to arrange for a US Forest Service archeologist to be on site if necessary. The Contracting Officer has the right to temporarily halt construction in the event that human remains, building remains, or if artifacts are unearthed during excavation as they may be significant to the historic nature of the property as its designation as a national historic site.

PART 2: MATERIALS:

2-1 The materials required are listed in the individual sections. Material not listed but required will be provided by the contractor. Provide all materials required to complete the work.

2-2 When materials shall be brought in from off-site samples shall be submitted for approval prior to delivery or use. All materials shall be clean and free of organic material, toxic or hazardous material.

PART 3: EXECUTION:

3-1 SILT FENCING: The Sawmill creek and Vantine brook are high quality streams and a permit will be required to work within the waterway, or where the work may have an effect on the waterway. The Contractor will be responsible for acquiring, and abiding by, the permit(s) issued by the local conservation district. Any protection measures (i.e., silt fencing) required by the permit(s) shall be provided, installed and maintained by the Contractor, if necessary, as determined by the Pike County Conservation District. Contractor shall see to the maintenance of the silt fencing during construction and shall notify the Contracting Officer or COR immediately should the fencing fail and cause the escape of sediments into the waterway.

3-2 TRENCHING: Excavation of a subsurface trench, 3 ½ feet wide and two feet deep, will be required for the installation of below-grade, compacted, modified stone, footings which will provide drainage and adequate support to the finished stone wall.

3-3 TRAIL RECONSTRUCTION: A gravel trail exists adjacent to the boundary wall in the lower field along Old Owego Turnpike. The trail exists inside the field area of the boundary wall. The trail is compacted 2A stone and will be impacted by the demolition, trenching, footing and stone wall installation in that area. The contractor is responsible to be re-established those sections of trail in the same method, dimensions and appearance, as the before the contractors work began, after the completion of the stone boundary wall.

September 15, 2018 Masonry Restoration Grey Towers NHS Section 04520-1

SECTION 04520 - MASONRY RESTORATION

PART 1 - GENERAL

1.01 RELATED DOCUMENTS:

A. Drawings and general provision of Contract, including General and Supplementary Conditions and Division 1 Specification Sections, that apply to this Section.

1.02 DESCRIPTION

A. Provide all masonry restoration or preservation work as specified by the contract documents, or as directed by the Contracting Officer, including the following:

1. Repair and reconstruct existing stone masonry walls, where deterioration has been identified, and conditions require, to match the craftsmanship, rhythm and random rubble appearance of existing (historic) masonry work.

2. Restore stone structures and details to their pre-existing (historic) appearance.

3. Rebuild or create mechanically compacted gravel (2A crushed stone) footings to provide adequate and stable support for the rebuilt, or repaired, masonry wall receiving the work.

B. Related work specified elsewhere: [Not Applicable]

1.03 QUALITY ASSURANCE

A. Contractor performing the work of this section shall have a minimum of 5 years experience in masonry restoration and repointing. The contractor and his lead masonry craftsperson(s) shall have successfully completed two masonry restoration projects within the previous 10 years of similar scope where the work met the "Secretary of the Interior Standards for Historic Preservation Projects".

1.04 SUBMITTALS

A. Test Panels: The Contractor shall prepare “sample panel(s)” for the work to be performed which will be used as a quality standard for the work of this Section. Do not dismantle or remove the Forest Service COR/inspector approved” test panels after acceptance until the project is completed. If an area on existing masonry walls is identified by the COR/inspector that can serve as the approved sample panel then the preparation of sample panel by the contractor then this respoinsiblity will be waved.

B. These sample panels shall be prepared for the following:

Grey Towers NHS Section 04520-2

a. Stone wall construction including the stone pattern and rhythm, laying of the stone and bonding, and general appearance of the stonework in the stone walls as they match the historic adjacent walls.

b. Characteristics of the mortar including: color, texture, and surface tooling of the finish pointing

C. Stone pointing at a selected area on a stone wall: 1 square meter of masonry, installed/applied in place at a specific area agreed upon by the contractor and the Forest Service. Approved panels shall become part of the work, and shall serve as a quality standard for all other similar work. Rejected panels shall be removed and repeated as required until work closely replicates the design appearance of the historic stone wall (existing), as determined by the COR/inspector.

D. Contractor will prepare a 3-6’ section of a 3 ½ foot wide and 18 inch deep, 2A modified stone gravel footing, with top one foot below grade. The crushed stone footing will be prepared for approval by the COR/inspector in conjunction with the contractor. This methods and materials used to create this approved footing will be used throughout the project below grade.

1.05 JOB CONDITIONS

A. Protection of Adjacent Materials:

1. Protect all existing adjacent materials during the execution of the Work.

Provide all necessary protection and work procedures to avoid damage to other materials not in this contract (i.e., doors, windows, flashings, roofing, pathways, etc.) and any other structures or feature components, their materials, or equipment.

2. The Contractor shall repair all damage to adjacent materials caused by the execution of the work of this section at no expense to the Owner/Government.

Damaged materials shall be repaired or replaced by mechanics experienced in the respective type of work, to the satisfaction of the COR/Inspector.

3. Protect any under ground or above ground utilities or drainage systems in the immediate area of work. Protect against any negative effects caused by, or resulting from contractor’s activities, as a result of their work products.

4. Protect waterways in the immediate area of work from masonry activities and other waste material which result from the contractor’s activities, whether contract-work related or the activities of contractor’s employees or subcontractors.

Grey Towers NHS Section 04520-3

PART 2 - PRODUCTS

2.01 STONE:

1) Reuse existing stone for all relaying and bonding of masonry. Cover and store all stone, prior to reuse, or determined to be surplus after work activities are completed, in an area approved by the Forest Service COR/Inspector.

2) If extra stone is required to complete the work according to the specifications, the contractor should purchase the required additional stone, which will match the existing stone in geologic type, size, texture, and color(s) to the extent possible with existing quarries in the surrounding counties.

3) All stone used in rebuilding the wall should be “faced” to a flat edge which will be used toward one of the exterior (outside) faces of the wall or feature. Round cobble faces used in the wall create over-sized mortar joints which are not stable or long-lived.

4) Crushed stone (2A modified) material to be used in creating the footing of the walls.

2.02 MORTAR MATERIALS AND FORMULAS:

A. Mortar formulas and mortar materials - general: At each type of masonry, match existing (historic or original) mortar in compressive strength, color, texture, general appearance and finish tooling.

B. Mortar materials - Standards:

1. Portland Cement: ASTM C150, Type I or II, white, mixing some grey, complying with the staining requirements of ASTM C91 for not more than .03% water soluble alkali.

2. Hydrated Lime: ASTM C207, Type S or SA.

3. Sand: ASTM C144, matching color and texture of existing mortar sand.

a. Sand component of the mortar shall match, to the greatest degree possible, the sand in the historic or existing mortar. This usually requires breaking down a small mortar sample with muriatic acid to reveal sand components.

b. This sometimes requires a blend of mortar sands to achieve the desired results.

5) Mortar Mixes: Provide the following mortar mixes for initial mortar tests.

1 Pointing Mortar will require that a test panel will be prepared once a match

Grey Towers NHS Section 04520-4 to the historic has been achieved. Final mortar mixes (formulas) which achieve a match to the historic mortar will be inspected, and accepted by the COR.

2 Interior Bedding Mortar for laying stone where mortar will not be seen on the outside wall face can be a different formula, color and appearance than the pointing mortar used on the exterior face of the stone masonry.

1 part by volume white Portland cement 1/2 parts by volume hydrated lime 4-5 parts by volume sand.

NOTE: Sand color & type will be dependent upon whether the mortar is to be used as a bedding mortar or pointing mortar.

Although sand used for pointing mortar can be utilized for bedding mortar, matching color is important characteristic in pointing mortar.

D. Mortar Mixing:

1. Mix mortars in accordance with ASTM C270.

2. Measure materials by volume or equivalent weight. Do not measure by shovel load.

3. Mix ingredients in clean mechanical batch mortar mixer for 3 minutes or by hand in a mud pan for 5 minutes.

4. Let mortar sit 20 minutes prior to use to allow for initial shrinkage. Do not re-temper partially hardened material.

E. Filter fabric: Six (6) ounce, woven filter fabric in 10 foot wide rolls used for wrapping crushed stone footings.

PART 3 - EXECUTION

3.01. MASONRY REPAIRS

A. Demolition Deconstruct the stone wall completely at the locations identified for restoration.

B. Site Prep Excavate a three and half foot wide trench two feet deep below grade to establish the new mechanically tamped, gravel footing.

C. Footing Contractor will prepare the footings that will provide support and

Grey Towers NHS Section 04520-5 drainage for the stone walls to be constructed in the location of the deconstructed walls. A crushed stone (2A modified) footing shall be installed in a manner approved and accepted by the COR/inspector. In the excavated trench install the filter fabric wrap to encase the 3 ½ foot wide x 18 inch deep footing.

D. In the filter fabric blanket install the crushed stone (2A) and tightly compacted using mechanical equipment to the dimensions required. After compaction finish wrapping the new footing with filter fabric and pin closed. This stone gravel footing shall be compacted to an adequate density so no movement/settlement can occur beyond

E. Savaged Stone Clean loose stones of remaining mortar from all sides, and discard old mortar. Old mortar debris shall be hauled away and disposed in appropriate manner and location in approved by State and local requirements.

F. Bedding mortar Install new setting bed of mortar to proper thickness to align top surface with surrounding stones according to existing bonding pattern. Bedding mortar shall not exceed the bedding and head joints of approved stonework panel”.

G. Bonding Fill joints around stones to properly prepare for adjoining work to bond.

H. Bed & head joint prep. Keep bed and head joints set back to accommodate future tuck pointing with approved mixture, tool finish, color and texture.

3.02. POINTING

A. The stone masonry will be laid with a bedding mortar but tuck pointing will be performed after the initial wall is set, since tuck pointing is performed as a finish treatment. The bedding mortar is held back, or cut back, to allow a ¾” to 1” of the pointing mortar.

B. Deep tuck pointing, or grouting is to be done only in those areas where voids in the existing pointing mortar would allow the grout to escape. When the voids in the wall are pressure grouted, enlarge existing mortar voids and cut out existing deteriorated mortar from joints in area indicated, to sound, mechanically adhered mortar, without injuring the edges of the stones. Removal of the old mortar shall be done with hand tools. If needed, mechanical/pneumatic tools can used if, approved by the COR/inspector prior to use.

C. Remove all loose material by brushing and/or blowing with compressed air. Wash out joints with low pressure water.

D. Fill joints toward the surface of the stone while retaining a recessed mortar joint.

Because the stone of this masonry work has curved surface, recessed joint should be set back a ¼ inch to 1/2 inch from the face of the stone. Apply, or tuck, pointing mortar applying pressure to insert mortar deeply into joint to leave no voids in the mortar between stone.

E. Remove any excess mortar which comes in contact with the stone surface prior to the end of the work day. Keep face of stone clean of excess mortar or smears.

F. Keep new pointing mortar damp for 48 hours after set to prevent cracking. In dry or hot weather moisten the surface twice a day for 2 days after mortar is set. new

Grey Towers NHS Section 04520-6 pointing from drying too fast or from freezing by covering with material (tarps or masonry blankets) to retain proper humidity for curing, or to prevent flash drying or freezing depending on daily or seasonal atmospheric conditions.

3.01 MORTAR CURING - GENERAL

A. Hot weather requirements - general: Provide all special precautions and procedures required to control mortar curing during hot weather. Comply with recommendations of "All-Weather Construction" Technical Note (Rev. March 1992) as published by the Brick Institute of America or Stone Masonry Institute.

1. No mortar shall be placed in full sun at temperatures above 90 degrees F unless shading of the walls is provided and the masonry wall temperature is kept below this point.

2. Maintain temperature of mortar between 50 degrees F and 90 degrees F. Use all measures required to achieve this temperature range, including storing brick and mortar sand under shaded cover, and chilling water used for mortar mix or other methods which will achieve the same desired result.

3. Protect and cure new pointing and rebuilt walls as follows:

a. For wall temperatures above 90 degrees F with no wind: Fog spray and cover walls with sheet plastic or canvas to control moisture evaporation during the day in which mortar is placed and during the following work day.

1) Repeat fog spray as often as required, but not less than once per hour during the day in which mortar is placed.

2) Do not use clear or black polyethylene sheeting as protective cover or other color or material which will cause heat build-up under cover (greenhouse effect).

b. For wall temperatures 80 - 100 degrees F with wind of 13 MPH: Fog spray and cover wall walls as specified in 3.01.B.4.a.1) above.

c. For wall temperatures 80-100 degrees F with no wind: Fog spray and cover walls with sheet plastic or canvas to control moisture evaporation during the day in which mortar is placed.

Grey Towers NHS Section 04520-7

1) Repeat fog spray hourly during the day in which mortar is placed.

2) Do not use clear or black polyethylene sheeting as protective cover or other color or material which will cause heat build-up under cover (greenhouse effect).

d. For wall temperatures less than 80 degrees F: No special mortar curing procedures are required.

B. Cold Weather Requirements:

1. No work in this Section should be executed when the ambient temperature is less than 40 degrees F, especially if temperatures were below 35 degrees in the 2 hours before scheduled work. No pointing shall be executed when freezing temperatures are expected within 48 hours after work is performed, unless measures are taken to adequately mitigate the lower temperatures.

2. If work is expected, or needs to be accomplished during cold temperatures, in coordination with the COR/Inspector, propose the means by which the wall/mortar temperature shall be heated or protected from freezing. (i.e., masonry blankets, heating devices, enclosures). Proposal should be made 48 hours before utilizing the techniques proposed and the COR must approve the proposed means and methods before use.

3.03 STORAGE, PROTECTION, AND CLEAN-UP

A. Materials and supplies which may be negatively affected or damaged by exposure to environmental conditions (temperature, moisture) shall provide the means for storage and protection of those materials. If materials (Portland cement, lime, or other components) are found to be not protected, these products may be rejected for use in the work of the contract and subject to replacement at the contractor’s expense.

B. The Contractor shall be held responsible for replacing in kind the masonry damaged during their, or their subcontractor’s, work progress, mobilization, or the activities of the contractor’s workers or the subcontractor’s employees.

C. Store materials under cover in a dry place in a manner to prevent damage or change in condition which could affect their appropriateness for their intended application.

END OF SECTION 04520