Building a Fence

Start here to plan your private backyard oasis

Check out this short, minute and a half video on the fundamentals of building a fence with pressure treated wood.

Use environmentally advanced treated wood, Ecolife® and Preserve® CA (Cpper Azole) for long term protection-- available from lumberyards in your area.

• Obtain appropriate building permits to help ensure your project is built to code for its intended purpose.
• Permits should be obtained by the builder of the project as they will ultimately be responsible for ensuring the project meets the appropriate code.
• Review and follow the requirements of any homeowners association (if applicable).
• Obtaining approvals for project design, appearance and location are likely prior to construction.
• Discuss outdoor projects with neighbors.
• This is especially significant as your treated fence project may involve property boundaries and/or impact sight lines.
• Construction should only be performed during regulated or approved work timeframes.
• Helps minimize issues related to noise pollution ordinances.

Be sure to know what obstacles you may encounter:

• Locate underground utilities, cable and phone wires, underground irrigation systems, landscape lighting and roots of plants and trees.
• Call 811 for assistance in locating utilities.
• For fencing projects that are adjacent to structures with footings, caution should be used not to significantly disturb the soil around or under the footers.
• If necessary, locate post slightly away from the structure and extend/ cantilever rails slightly to bring finished fencing closer to the structure.

When planning your fencing project, be sure that its location or construction doesn’t interfere with required clearances from adjacent items or emergency egress requirements:

• Be very mindful of any exhaust outlets for heating sources (i.e. furnaces, fireplaces, water heaters, etc.) to prevent burn and carbon monoxide-related issues.
• Exhausts with high moisture amounts (i.e. dyers, exhaust fans, etc.) should have very adequate ventilation to help prevent wood-damaging fungi from flourishing.

Check out this short, minute and a half video on the fundamentals of building a fence with pressure treated wood.

• Post
  • A structural member that is treated for Ground Contact applications that the fencing rails are connected to.
  • End or Corner Post is located where a fence either begins/ends, at each side of the opening for a gate, or where the fencing comes together to make a corner.
  • Line posts are appropriately located between the End or Corner posts, creating a point to fasten the fencing rails.
  • Landscape timbers are not suitable as supporting posts or rails for fencing projects
• Rails
  • The horizontal pieces that span between the posts, either as part of a finished fence or as a member to fasten fencing pickets to.
• Pickets
  • The vertical wood pieces/strips that are attached to the rails.
  • Pickets can come in a variety of widths and configurations and can be installed in different ways to create a customized appearance.

When planning your treated fencing project, consideration should be given towards the purpose of the fence and selecting the appropriate style, height and restriction of airflow.

• Privacy
  • Generally used to block the view for personal privacy or appropriately conceal of contents.
  • Blocks direct view and can significantly reduce airflow.
  • Popular styles involve boards that are installed tightly against each other and high enough to generally not be seen over directly from another side.
• Semi-private
  • Generally allows for a semi-obscured view and some airflow.
  • Popular styles involve staggered or spaced boards.
• Visual boundary or accent
  • Generally used to convey a segregation of an area, or to add distinctiveness to a designated area.
  • Popular styles include various post & rail configurations.
• Containment
  • Generally used for children or animals.
  • Height and style may be impacted by what is being contained.
  • Physical capabilities with regards to climbing, jumping, digging, pushing, etc.
• Popular styles may range from shorter-height, semi-private designs to taller privacy configurations.
  • Some options may include a supplemental metal fence being attached to the inner side of a post & rail configuration.

Select the type of fencing construction that best fits your needs and construction willingness or abilities:

• Pre-assembled Panels
  • Usually available in popular sizes and configurations ranging from privacy to open design.
  • For flat areas or where varying gaps underneath, or heights from section to section, are acceptable.
• Post & Rail
  • Usually intended to provide visual boundary without significant obstruction of view.
  • Fairly simple design for various terrain options.
  • Rails are commonly installed parallel to the ground and can vary in width, quantity and angle to alter the final appearance.
• Picket Fence
  • Individual pickets in various or mixed sizes are attached to rails in a variety of spacings and locations to create multiple appearance options and fence types.
  • Pickets can be installed on only the outer side of the rail or alternate between sides.
  • Width, height and spacing of pickets can vary to achieve different styles and privacy options.

The terrain of the where the fence is to be located may determine or limit some options:

• Flat
  • Fencing line lines are reasonably level with minimal height variations.
  • Ideal for Pre-Assembled Panels, or any other types.
• Uneven
  • Fencing lines are somewhat level with some variation in gaps or heights.
  • Pre-Assembled Panels and Post & Rail options may allow for varying gaps under the fence.
  • Picket Fence type fencing may provide more options.
  • Pickets can be installed as an absolute mirror of the contours, with picket height varying from piece to piece.
  • Longer pickets can be cut to better match terrain variances while maintaining a somewhat uniform height appearance.

• Sloped
  • Fencing lines are not even and the ground is generally pitched.
  • Pre-assembled Panels mounted level will have a “stair-stepped” or “terraced” appearance across the tops with unavoidable gaps underneath.
  • May require unusually long posts to reach highest, level point off of sloping ground.
  • Rails for Post & Rail and Picket fence types are commonly constructed to generally be parallel to the slope of the ground.

Mark Your Projected Fence Line

• If the fence line is intended to be straight, use wooden string pulled tight and fastened to stakes to identify the outer boundary as a guide.
• Use a single guide string to represent each run, extending 1’-2’ past each corner.

• To ensure your corner is square, measure 3’ from the point of intersection on one string and 4’ on the other string; the distance when measured directly between these two points should be 5’ for the corner to be square.

• To determine post placement from the guide string, cut a scrap piece of fencing picket and backer rail material to combine as a spacer for the rail distance from the string.
• This helps keep the string out of the way when digging holes and helps align the face of the pickets to an object (i.e. corner of the structure, etc.).

• Mark the location of each post on the ground.
• Corner and End posts should be located first.
• Line posts are centered where backer rails are anticipated to meet each other.
• Starting with a single corner post, be sure to allow one rail to extend beyond the post (using the spacer as a gauge) to allow the other rail at that level to butt up against it and make a complete corner.

As a general guide, it’s best to have at least 1/3 of your post in the ground for stability, but not less and 2’.

• Local building codes, freeze/thaw lines, soil consistency and anticipated wind velocities may increase the amount of the buried post.

• Dig holes wider at the bottom to help prevent settling and add stability.

• Make the hole deep enough to be at least a few inches below the frost line for your area.

• Fill the bottom of each hole with 4”-6” of packed gravel to help remove moisture from directly under post that may make it rise during ground freezing.

• For Pre-assembled Panels on uneven or sloped terrain, be sure to get and install posts tall enough to allow fastening of top rail at its highest, level point off the ground.

• Be aware of differences in required post lengths when layout posts prior to setting.

Install posts with original, factory-cut ends into the ground whenever possible.

• Note: If the 4x4 posts are Southern Yellow Pine (common east of the Rocky Mountains and can be verified by the “SYP” grade stamp on the lumber) and treated with Preserve CA (listed on the end tag as CA-C), then treating the end cuts is not required. If you are on the West Coast, where refractory species of wood are more commonly treated, cut ends do require coating with copper naphthenate.

  Install factory-cut ends of posts into the ground as the pressure-treating process infuses preservative deeper into the exposed post ends.

  Exposed tops that are trimmed should be done so in a manner that sheds water or use a decorative/protective post cap.

  Water left to repeatedly accumulate on ends of a post can promote saturation of wood and promote wood-damaging fungi growth.

• Ensure post is vertically plumb and spaced appropriately from guide strings (for straight fence line).
  • Use temporary wood bracing and stakes to securely brace plumbed posts in place while concrete is added to the fill hole.
  • Ensure that outside corner post faces are square to the intersecting fence lines and, using the spacer, is appropriately set back from the guide string (if used) or planned outside corner on both outside facing sides of the post.
  • Ensure line posts are square to the fence line and, using a spacer, appropriately inset from guide string (if used).
  • Ensure end posts are square to the fence line and are aligned with the anticipated edge of the end of the rail.
• Add mixed concrete to fill hole above the soil line, sloping it downwards to shed water.
  • This helps reduce the opportunity for wood-destroying fungi to flourish around the posts.
  • This may potentially also help reduce damage from trimming surrounding grass/weeds with a string trimmer.

Bottom rails and fence pickets are not necessarily intended to be used for retaining soils and mulches.

• Other than fencing posts, components treated for Above Ground use should be installed above the current or projected soil level to reduce the potential for fungal rot to develop.

• Keep debris from accumulating against bottom of fence to reduce the opportunity for attack by wood-destroying fungi.

• Metal or plastic fencing, or a piece of treated wood for ground contact, can appropriately be attached to the bottom of the fencing (closer to the ground) to help keep animals contained.

Fasteners

Appropriately-sized, hot-dipped galvanized or stainless steel fasteners should be used to assemble fencing components.

• Reduce likelihood of fasteners rusting or corroding, which could lead to unsightly staining and fencing collapse/failure.
• Fasten rails to posts, and pickets to rails.
• Use ring-shanked or spiral twisted nails, or screws, to help increase holding power.
• Consider using appropriate screws to attach rails for at least one section of fence to allow for potential future access of larger equipment.
• Ensure fasteners are long enough to hold well but aren’t too long and don’t protrude, especially when installing pickets to rails.
• Use adequate hardware for attaching gates to posts.

Pre-assembled Panels

Install level panels on posts, securing them using fasteners through the backer rails into the posts.

• Trim panels to length as needed by cutting the backer rails.

Rails are commonly installed relatively parallel to the ground and to each other.

• Pickets should be installed vertically plumb to backer rails (as desired).
• As a guide, the top and bottom rails should be installed within 6” of the ends of the pickets.
• 3 rails are suggested for pickets 60” or longer.
• A spacer can be developed/used to ensure spacing remains consistent.
• Check every ~6th picket at minimum to ensure they are being installed vertically plumb and adjust as necessary.
• Depending on the type of appearance desired, pickets can be installed in various configurations.
• Picket sizes, heights and spacing can be adjusted for a customized appearance.
• A single fastener per rail may be adequate for material with pickets with a nominal dimension of 4” or less.
• It’s recommended that pickets greater than 4” nominal width, or in areas prone to high wind scenarios, use 2 fasteners per rail.

Because the weight of the gate will only be supported by one side, it’s important that the frame of the gate be constructed in a sturdy manner that helps keep it square and transfers the weight to the hinged side.

• Construct a wooden gate frame that includes a tight fitting, diagonal brace from a single piece of wood that goes from the bottom corner of the hinged side to the upper corner of the opposite side.
• Be sure to consider how the hinges will be mounted (surface/flush versus concealed/hidden) and allow enough space between the frame and opening for them to work correctly.
• Appropriate builders hardware can be added to help keep the framework square
• To aid in keeping the gate square, consider adding diagonal bracing that goes from the top corner of the hinged side to the opposite bottom corner.
• An adjustable turnbuckle can be used to allow for future adjustments in the event some sagging occurs.

• Remember, the overall weight of the gate will increase as additional bracing materials are added to keep it square.

Use appropriate builders hardware to mount, hinge and latch the gate between the posts.

• On a single gate, mount a wooden stop strip on the non-hinged post, directly behind the gate frame to help keep it from being pushed beyond the flush, closing point and straining the hinges/fasteners.