Loading...
HomeMy WebLinkAbout2024-06-11-TREE-min-attach3 Figure 13 PROTECTING TREES DURING CONSTRUCTION I dripline driplinc I I Tree Save Are.a, r f 4 critical root zone ` • Install a protective fence to create a Tree Save Area. The Tree Save Area is defined as the area within the drip line of a tree, or the area within a radius around the tree trunk of 1 foot for every inch of DBH, whichever is greater. o Use 5' high chain link or welded wire with stable metal stakes or posts spaced a maximum of eight (8) feet apart. o If protective fencing cannot be installed at the dripline of a tree, then it should be installed as far away from the tree trunk as possible, ideally a minimum of six (6) feet. o Each fenced Tree Save Area shall include signs reading, "TREE SAVE AREA— PLEASE KEEP OUT"/ "AREA DE MORRO DE ARBOLES — ENTRADA PROHIBIDA POR FAVOR", in both English and Spanish and should be placed in a highly visible location. o Tree protection shall be placed before ground disturbing activities, including tree removal and demolition, start and shall remain in place until all construction has been completed. • Trunk Protection: If the protective fencing can not be installed to protect the tree trunk then trunk protection should be installed. Loosely tie protective 2x4 lumber around the tree trunk with rope, do not use wire. Attach the rope to the 2x4's using staples. Do not drive fasteners into the tree. Height of the lumber shall be from the tree base including root flare at the bottom of the first branch, typically six to eight (6-8) feet. The 2x4 lumber should be angled so the trunk flare and buttress roots are also protected. Closed cell foam padding, one-quarter (Y4) inch thick minimum, can be placed between the trunk and the lumber for added protection. • Soil Protection: Avoid compaction of the soil by keeping foot and vehicle traffic and storing of materials away from the root zone and outside the Tree Save Area. In cases where allowing access through the tree save area is unavoidable either a minimum one-half (1/) inch steel plate placed on top of a two (2) inch minimum bed of mulch (e.g. wood chips) or a minimum of three-quarter (3/) inch plywood over a four (4) inch bed of mulch may be used to bridge over the protected root zone in the tree protection area. • Take special care with backhoes and other machinery to minimize damage to roots, trunk, limbs and overhead branches. Figure 14 EXCAVATION and TUNNELING WITHIN DRIPLINE " 111dn e " " Trench Tunneling " " (40%root kill) ; saves roots ; R001' 'I 1JNNEL,1N(j' PRUNING • Excavate around tree roots or tunnel under the root zone. Trenching without proper root pruning can severely damage roots. • Tunneling is preferred to root pruning, where possible. • Root pruning by or under the supervision of a certified arborist must be done prior to excavation or grade change any time work encroaches on the critical root zone. o Excavate using an air spade, hydro excavation or hand tools to expose roots. o Cut roots cleanly, removing no more than forty (40) percent of roots. o Backfill and water immediately o If the hole must be left open past the end of day, cover roots with wet burlap. o Monitor tree health and supply adequate water and mulch. Figure 15 GRADE CHANGE GUIDELINES new grade previous grade MAINTAIN EXISTING GRADE AROUND TREE Protect trees by creating terraces with retaining walls to maintain the original grade around the root zone. Cutting or shaving roots or piling soil on top of roots to create a continuous new grade will slowly kill the tree. Avoid drainage changes that could mean a tree gets too much water or not enough. • If a grade change is needed within the critical root zone, root pruning is required before that grade change is made. See Figure 14.