Attachment A. Wildlife Friendly Livestock Fence Specification.pdf

Midpeninsula Regional Open Space District

Wildlife Friendly Livestock Fence and Gate Specifications

a. All fencing materials will be new, unless an exception is noted;

b. Fencing materials shall conform to the requirements of American Society for Testing and

Materials (ASTM) Standard Specification ASTM A121 for barbed wire and ASTM A854 for high-tensile wire. Barbed wire shall be Class 3 zinc coated as specified in ASTM A641 unless otherwise specified. High-tensile wire shall have type I zinc coating unless otherwise specified. Aluminum wire requires no protective coating;

c. Total height shall be 54”;

d. Fence shall be constructed of five (5) strands: upper four (4) strands shall be galvanized

4- or 5-point barbed wire (12.5-gauge for standard wire; 14-gauge for high-tensile) and bottom strand shall be smooth (12.5-gauge);

e. At least 12” between the top two wires;

f. At least 16” between the bottom wire and the ground;

g. Fence shall use 6- or 7-foot steel T-posts weighing not less than 1.33-pounds per foot of length, exclusive of anchor plate. Steel posts are to be studded, embossed or punched for the attachment of wire and have an anchor plate near the bottom of the post. Steel line posts shall be rolled from high carbon steel and have a protective coating of galvanizing by the hot dip process;

h. T-posts shall be spaced apart no further than on 10-foot centers; depending on terrain and grade, closer spacing of T-posts may be required to ensure that bottom wire is no lower than 16” from ground;*

i. H-brace + N-brace are required where fence starts and terminates and on both sides of installed gates.* H-brace cross member is required to be at least 10 feet in length. N-brace diagonal cross member is required to be at least 8 feet in length.

j. Leg braces are required for turns 5°-25°*

k. Double H braces are required on corners (>25°)*

l. Bracing is required to either be welded or to be constructed using welded tabs and bolts.

Other construction methods may be acceptable but must be approved by District Representative.

m. Galvanized Schedule 40 3” OD pipeline posts approximately every 100 feet or on turns/corners (see requirements for leg braces and double H braces above)*

n. Pipes and braces shall be galvanized schedule 40 steel. Galvanized fence posts may either be driven into native soil no less than 4 feet deep or may be set in concrete no less than 3 feet deep; if setting in concrete, contractor shall use no less than 240 pounds of concrete for fence posts (2.875” OD) and no less than 320 pounds of concrete for heavy duty gates posts (6” OD).and sunk a minimum of 4 feet deep*

o. ‘Dead Man’ anchors shall installed where bottom wire exceeds 18” above ground*

p. Gates shall be hot-dipped galvanized and have the following minimum specifications*:

i. “Medium” duty

1. At least 20-gauge steel

2. At least 1.66” OD tubing

3. 6-rail

4. Medium-duty gates shall have H-braces on both sides of gate

ii. “Heavy” duty

1. At least 16-gauge steel

2. At least 2” OD tubing

3. 6-rail

4. Heavy-duty gates shall be hung on 6” OD Schedule 40 galvanized pipe posts; pipes may be driven into native soil no less than 4 feet deep or may be set in concrete no less than 3 feet deep; contractor shall use no less than 320 pounds of concrete

*Specification(s) may be amended in consultation with but at the sole discretion of District Representative