SECTION TREE & PLANTING PROTECTION

Transcription

1 SECTION PART 1 - GENERAL 4.1 SUMMARY A. The work includes labor, equipment, and materials necessary for existing tree & plant protection, tree trimming and protection of the Critical Root Zone (CRZ). B. Contractor shall contact the zoo's arborist to perform any pruning tree or repair work recommended. If damage occurs due to construction operations, the arborist shall make repairs promptly to prevent progressive deterioration of damaged trees. Any pruning, cabling, root treatment and tying back of limbs will be per recommendation and approval by the arborist. C. Trees, shrubs, and other understory plants within the critical root zone that are not designated for removal shall be protected during clearing, tree removal and construction operations. Protect the root system, trunk, limbs and crown from breakage, scarring and prevent soil compaction or chemical contamination. Contractor shall prevent any contamination of the soil within the Critical Root Zone by construction materials, debris, silt, fuel, oils, concrete or any other chemical substance. Contractor shall notify the Architect of any such spills, compaction or other disturbance within the critical root zone and take immediate corrective action using methods approved by the Zoo. D. The contractor shall provide tree protection signage that must remain posted at designated trees inside the construction zone for the duration of the project. E. Related Work Specified Elsewhere: 1. Section Demolition 2. Section Clearing and Grubbing 3. Section Earthwork 4. Section Plants 4.2 QUALITY ASSURANCE A. The applicable provisions of the following standard publications shall apply throughout this section: 1. American National Standard for Tree Care Operations - Tree, shrub, and other woody plant maintenance - standard practices, - ANSI , published by American National Standards Institute, American National Standard for Tree Care Operations - Tree and shrub transplant standard practices 3. American National Standard for Tree Care Operations - Pruning, trimming, repairing, maintaining, and removing trees, and cutting brush - safety requirements ANSI Z , - published by American National Standards Institute, Pg 1 of 7

2 4. Arrange a pre-construction meeting to review schedule, specifications, and tree protection operations. 4.3 SUBMITTALS A. Name of certified arborist for the project including certificate number and stamp. B. Product Data: Submit product literature with name of product manufacturer's name and compliance with specifications. 1. Pesticides (herbicides, insecticides and fungicides, etc.) 2. Anti-desiccant C. 1 lb. resealable plastic container of proposed mulch. D. Schedule and Work Plan: Submit detailed schedule and work plan for each part of the work. E. A plan of the site showing the location of protection fencing, trees to be removed. 4.4 REGULATORY REQUIREMENTS A. Comply with rules, regulations, laws and ordinances of local, state and federal authorities having jurisdiction. 4.5 PROJECT CONDITIONS A. Existing Conditions 1. Carefully examine the site before submitting a bid. Be informed of the site conditions including adjacent properties, utilities and soil conditions. 2. Should the Contractor find any discrepancies between Drawings and physical conditions inform the Owner's representative immediately for clarification. 4.6 ENVIRONMENTAL CONDITIONS A. Do not perform root pruning, tree removal or tree protection work within the Critical Root Zone area at times when the soil is wet or muddy. 4.7 PRE-CONSTRUCTION COORDINATION A. Prior to the start of construction, the Contractor and Architect shall meet at the site and review the locations of the following: 1. Existing trees to be protected and transplanted, trees to be removed from the site and trees to be removed and stockpiled for use in the project. The procedures and methods to be used to execute the work shall be reviewed during this meeting. 2. Areas for stockpiling trees for permanent removal, stockpiling of trees to be removed and used as snags in animal yards, stockpiling mulch, stockpiling topsoil, concrete wash-out, stockpiling of demolition debris, storage of construction materials, construction trailers, and other incidental contractor needs. Failure to comply with these reserved areas can result in immediate work stoppage and delays due to correction of non-compliance shall be at the contractor's expense. 4.8 TREE AND PLANT PROTECTION A. Operation of equipment, storage of materials, disposition of excavated material, and construction in general shall be conducted so as not to encroach into tree preservation areas. Injuries to tree trunks, branches or roots shall be the sole responsibility of the Pg 2 of 7

3 contractor. Trees and/or groups of trees and plants designated to remain shall be protected by tree protection fencing. B. The Contractor shall be responsible for providing any additional temporary fencing during the work as necessary to protect vegetation. Provide 6' chain link fencing or plywood boxes as required to protect trees, which are to remain free from any damage above and below grade throughout the construction period. Fencing shall extend to tree CRZ minimum. Erect and have approved by the Certified Arborist prior to commencement of demolition work C. Construction, when necessary and approved by the Architect, within the critical root zone shall be performed in a manner that avoids injury to the trees and their roots. 1. In general, construction as designated within the critical root zone shall proceed with extreme care either by the use of hand tools or equipment that will not cause damage to the trees. 2. Need for trimming of tree branches that interfere with construction shall be coordinated with the zoo' arborist. Trimming of branches and the cutting of roots shall be in accordance with accepted arboricultural practices and be performed by the Certified Arborist as designated in section PART 2 - PRODUCTS 5.1 TREE PROTECTION FENCING A. Minimum specifications - Construction style chain link fencing with concrete supports. Panel widths to be a maximum of 8 feet. 5.2 TREE PROTECTION SIGNS A. Heavy-duty cardboard or metal signs 12 by 12 inches attached to 3/4 inch thick exterior grade MDO plywood (or other substrate as recommended by the sign supplier). Sign shall have a blaze orange background with black block letters, 1 inch high, with the inscription "No Construction Activity - Tree Protection Zone". B. Signs shall be attached to the tree protection fence at intervals not to exceed 25 feet on center. 5.3 TREATMENT MATERIALS A. Pesticides: Approved before use for type and rate of application by and local, state, and federal agencies with jurisdiction. B. Anti-desiccant: 'Wiltpruf as manufactured by Wiltproof Products, Inc., P.O. Box 4280, Greenwich, CT 06830, (203) , or approved substitute. C. Chip mulch 1. Hardwood chips shall be produced by a disc style chipper, aged a minimum of six months and shall be free of non-wood material, including plastic, glass or leaves. Chips stockpiled from the tree removal operation may be used. D. Construction Mat 1. Construction matting will consist of 3/4 inch plywood or heavy gauge steel plates with an underlayment of a minimum of six inches of wood chip mulch. The Pg 3 of 7

4 plywood or steel top layer shall only be applied where vehicle movement is anticipated and shall not be kept in place for extended periods of time. PART 3 - EXECUTION 6.1 PREPARATION A. Prior to construction activity at the site, install tree protection fencing, tree protection signs and wood chip mulch as indicated in the project drawings and in accordance with the marked Critical Root Zone. 1. Signs and fencing shall not be attached to trees to be preserved. 2. Tree protection fencing and signs shall remain intact for the length of the project, damaged fencing or missing signs shall be repaired or replaced promptly. 3. Fencing shall not be taken down to store equipment or materials. B. Do not park vehicles or equipment, store materials or stockpiled soil, dispose of building materials, chemicals, petroleum products or other detrimental substances within CRZ of protected trees. Protect plant material from flame, smoke and heat. Construction access to site shall not occur beneath drip line of plant material. C. Tree flagging: 1. Trees flagged for complete removal and disposal: Mark trees scheduled for complete removal and disposal with orange paint in a band completely encircling the trunk of the tree. 2. Tree snags for animal yards: Mark trees to be saved for snags with a different color paint approved by Architect. In coordination with Architect, mark places on trees where cuts are to be made. Coordinate with Owner as to location for stockpiling of snags. D. Identify equipment ingress and egress pathways in the pre-construction walkthrough for inspection and approval by the Architect: 1. Equipment pathways shall avoid critical root zones, except as approved by the Architect Any approved access within the critical root zone shall use an approved construction mat. 2. Additional vertical clearance required for equipment access shall be reviewed and approved at the pre-construction walk-through. 3. Equipment shall not be parked within the critical root zone. 6.2 EXISTING TREES TO REMAIN A. General: 1. Provide 6' high chain link or 4'x4'x8' high plywood fence at tree CRZ. 2. Thoroughly water disturbed areas prior to placement of wood chip mulch. 3. Root zones shall also be protected with 12" of wood chip mulch to prevent compaction. Keep wood chip mulch 12" clear of tree trunk. Remove wood chips prior to placement of finished grades. 4. Where fencing is not possible due to obstructions, walkways, or other conflicting elements notify Architect for alternative fencing locations. 5. Restrict foot and vehicular traffic over root systems to prevent excessive compaction of soil Pg 4 of 7

5 6. Under no circumstances shall the Contractor remove or alter existing trees designated to remain for the convenience or ease of construction. 7. An effective silt fence of geotextile fabric supported by wood or metal fenceposts shall be maintained between sources of silt and the critical root zones. B. Excavation Around Trees: 1. Excavate within CRZ of trees only where shown. 2. Where excavation or construction is required within CRZ, water tree thoroughly a few days before work is to begin 3. Where trenching for utilities is required within CRZ, tunnel under or around roots by hand digging. Do not cut main lateral roots or tap roots. The Contractor shall notify the Architect prior to cutting roots over 3/4" in diameter. Certified arborist shall cut roots larger than 3/4". Contractor may be allowed to prune roots with approval and direction from certified arborist. Make clean cuts. 4. Do not leave roots exposed to sun or other drying. Protect exposed roots with damp burlap or wood shavings within 1 hour of initial exposure. 5. Where excavating for new construction is required within drip line of tree, excavate by hand to minimize damage to roots and perform as follows: a. Comb soil in direction of root growth to expose roots. b. If main lateral roots are immediately adjacent to location of new construction cut roots three (3) inches from new construction. c. Do not allow exposed roots to dry out before permanent backfill is placed. d. Provide temporary cover with damp burlap or wood shavings. e. Water and maintain in moist condition until covered with backfill. 6. Open trench inspections for hand dug areas a. areas designated for hand digging shall require an inspection by the Architect prior to backfilling, to assess the extent of possible root loss or damage. The Architect may also require inspection in certain areas approved for excavation with mechanical equipment. b. Should the contractor backfill any of these locations prior to the Architect's inspection, the Architect may require the contractor to remove the backfill material, at the contractor's expense, as necessary to complete the required inspection. c. The contractor shall provide the Architect with a minimum of 24 hours notice on planned excavations requiring an open trench forestry inspection. C. Grading and filling around trees 1. Maintain existing grades within CRZ of trees unless otherwise indicated or approved by Owner. The Certified Arborist will evaluate the extent of backfilling within the tree root zone of a protected tree and make recommendations if necessary. Fill material to be per Earthwork, Planting and Soil Preparation sections. D. Repair and Replacement of Trees: 1. Plant material protected within fencing that becomes damaged or dies shall be replaced with plant material of the same species and equal or approved size Pg 5 of 7

6 2. Contractor to engage and pay for a certified and licensed arborist to perform tree repair work damaged by construction operations. Make repairs promptly after damage occurs to prevent progressive deterioration of damaged trees. 3. Damaged and destroyed trees which cannot be replaced shall be paid for at the rate of $50.00 per square inch of cross sectional area measured three (3) feet above existing grade for trees up to and including six (6) inch caliper, and at the rate of $ per square inch of cross sectional areas measured three (3) feet above existing grade for trees greater than six (6) inches caliper. This amount shall be credited to the Owner. 4. Remove any damaged and destroyed trees from the site as determined by the arborist to be incapable of restoration to a normal growth pattern. Deliver to Owner. Repair the ground surface. Costs shall be borne by the Contractor. 5. Replacement plants shall be in good health and approved by Owner before installation. E. Irrigation of Trees During Construction 1. Ensure trees are irrigated during construction to maintain health of the tree. 2. Water trees deeply at regular intervals and a minimum of once every two weeks during the growing season. The water should penetrate the soil to a depth of at least six inches 3. Take necessary precautions to prevent over watering, excessive run-off, and erosion from occurring. 4. Do not irrigate if specified irrigation requirements occur naturally through rainfall. 6.3 TREE REMOVAL A. Trees indicated for complete removal and disposal shall be removed in a manner that will not damage adjacent trees or cause injury to people or property. B. An ISA Certified Arborist shall supervise all tree removals. 1. Tree removal service provider shall be experienced with tree removals in areas of limited access. 2. No trees to be removed shall be pushed over or uprooted within 50 feet of a remaining tree's critical root zone. C. Coordinate placement and stockpiling of removed trees with Owner. 6.4 TREE SNAGS/DEADFALLS A. All trees tagged for preservation as snags for future use in animal yards shall be cut as directed by Architectand stockpiled in a location directed by Owner. Trees shall be cut in a manner that will not damage adjacent trees or property or cause injury to people. 1. An ISA Certified Arborist shall supervise all tree removals. 2. Tree removal service provider shall be experienced with tree removals in areas of limited access. 3. No trees to be removed shall be pushed over or uprooted within 50 feet of the critical root zone. 4. Snags shall be cut according to Architect's direction. 5. Stockpile snags in location approved by Architect Pg 6 of 7

7 6.5 TREE TRANSPLANTS A. The Owner is responsible for all tree tranplants prior to construction. The Contractor shall verify with the Owner 6.6 STUMP REMOVAL A. Location of existing and proposed underground utilities shall be identified prior to any stump removal. B. Stumps 12 inch diameter or greater shall be ground to a depth of 12 inches below existing grade in areas where site excavation does not occur. C. Wood chips, shavings, and debris from this operation shall be removed and properly disposed of or used as mulch on site if accepted by architect. D. Contractor shall backfill the stump holes with an approved backfill material.. 1. Compact to 85% of the maximum dry density in areas outside of the CRZ. 2. Compact to 80% of the maximum dry density in areas within CRZ E. Trees less than 12" in diameter shall be removed flush with existing grade. F. No stumps shall be dug or pulled within the CRZ. 6.7 TRIMMING OF EXISTING TREES A. Engage a qualified arborist to selectively remove branches from trees. Do not prune unless approved and directed by the Owner's representative. B. Cut branches with sharp pruning instruments and do no break or chop. Prune to outside edge of branch collar per ANSI pruning standards. END OF SECTION Pg 7 of 7