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Home Improver Guide 3
TIMBER FENCE
 

HINTS ON DESIGN   |  CONSTRUCTION |  A GOOD NEIGHBOUR FENCE  
HOW TO SHAPE A ROUNDED ARCH  | GATES AND ENTRY WAYS

Timber fences and outdoor screens can play a major role in creating character and giving definition to your yard.  Apart from defining the property line and providing the usual street and neighbour privacy, timber fences and screens can be employed as a landscaping aid in many other ways.

They can create special areas for either outdoor entertaining or children's play.  They can screen off clothes line or rubbish bin areas, as well as affording protection for  pools, gardens, the family pet, or from cold winds. 

Timber fences can also help control sun, shade, breezes and the ever encroaching traffic noises.

Finally, never underestimate the power that a well designed timber fence has to complement your home, adding distinction and above all, giving perspective to your house and view.

Simple creativity is often the best.  With a few simple cuts the humble timber fence need not appear so humble, as timber provides the owner with an unlimited pallet of colours, texture and design flexibility.
 

1. HINTS ON DESIGN  top

1.1  To begin, identify any potential problems your fence may create with a true -to-scale plan showing all permanent fixtures like trees, gardens, driveway and gate etc, and relate this to the direction of sun in winter, prevailing winds  and slope of land.  If a future pool is likely, design your fence now to comply with the pool fence regulations (see our Home Improver Guide No 2 Pool Fences).

1.2  Keep in mind when designing your fence that curves, corners, alcoves and seating will add strength to your fence while decorative openings for plants or tree limbs will add character.  So be adventurous!

1.3  Gates need not always blend in with the fence, but can offer a contrast in lines or texture to announce its position.

1.4 Consider using lattice screens at the front of the house to maintain visual privacy from the street or driveway without creating a prison yard syndrome.

1.5  Fence posts can be extended to incorporate features such as lighting, bird house, weather vane, or an overhead pergola style trellis, providing  privacy from high-rise neighbours.

1.6  Give your fence a finished look and extend the life of the palings by trimming the top neatly with a capping rail and protecting the bottom with a plinth rail.  Here the palings are kept at least 100mm clear of the ground and a plinth board is used to fill the gap.

1.7 Select the fencing timber you use for quality and durability, not just for price.  Suitable timbers are CYPRESS, DURABLE HARDWOOD   and TREATED SOFTWOOD.

CONSTRUCTION  top

2. TIMBER LIST FOR BASIC FENCE

2.1  Using your scale drawing, mark in all corner and finishing or gate posts (a).  Then divide the spaces between these posts into intervals (normally 2.1m).  You will need  2 intermediate fence posts   (b) (See Figure 1).  Your will need two rails for fences up to 1.5m high (c) and 3 rails for fences over 1.5m high (d) Try to purchase rails at least twice the length of the post spacings (4.2m) and stagger the joins on alternative posts for a stronger fence (Refere to figure 6 ).

2.2  Calculate:

(a)  Nº of 100 x 100 corner and gate posts
(b)  Nº of 100 x 75 intermediate posts
(c)  Nº of 75 x 50 or 100 x 38 rails (2 per bay)
(d)  Nº of 75 x 50 or 100 x 38 rails (3 per bay)
(e)  Nº of palings, using this easy formula
      Nº of palings =        fence length in metres x 1000
                                    paling width + gap

Allowance will also need to be made for bolts, nails,   concrete, capping, plinth rails and paint.

3. PLOTTING THE FENCE LINE

3.1  First, check with your local building authority or for any covenants that may restrict the height, set-back from the street and type of fence you may build.  You must also reach an agreement with the neighbours about design, height and who pays for what.

3.2  Correctly locate your property boundary and the corners of your fence.  Dig your post holes to a depth 1/3 the height of your fence, then stand and brace your post in the holes.  The centre line of the post should be positioned over the line of the fence or boundary.  Check that both posts are plumb and at the correct height before setting them permanently.  (See Figure 3 and "Note On Post Setting".)

4. SETTING THE POSTS

4.1  Setting and aligning the intermediate posts is the most difficult part of building a fence, so a lot of care is needed.  Stretch two string lines between the corner posts, one at the top and the other at the bottom.   Measure along the top string line and mark the intermediate post positions.   Then transfer this mark to the bottom line using a plumb bob (See Figure 2).

4.2  Set each post in the ground and check verticals.   when all the posts are in make a final check by eye along the fence line.  On a sloping site you need to decide what contour your fence will follow (See Figure 4).

5. ADDING RAILS

5.1  After the concrete is 4 days old, lay the rails on saw stools beside the posts to which they will be bolted, remembering to stagger the joints (See Figure 6 ).

5.2  Mark and trim the ends of each rail to fit its position and butt join or half check those ends which will couple with other rails (See Figure 5).  Mark and drill the bolt holes in the rails to correspond with the posts.

5.3  Now you have marked cut or checked all the rails, apply an oil primer or preservative to all surfaces where rails and posts touch for protection against decay.

5.4  Clamp each rail in turn to the post in their correct position and drill through the post via the holes already made in the rails.   Bolt each intersection using 1/10mm cup head bolt.

6. ATTACHING PALINGS

6.1  There are a number of materials you can fix to the rails to create a fence.  Palings are probably the most common material used.

6.2  Attaching palings is a simple operation, but one of the most tedious.  For instance, if you are erecting a 30m fence using standard palings, you will drive more than 1000 nails.  For large fencing jobs consider the merits of hiring a suitable nailing gun.

6.3  Before fixing, treat the paling with  a coat of paint or stain.

6.4  Cut a piece of timber the exact width of the gap used in the calculation (2.2) and attach a small cleat to one end.  Use this as a space block by hanging it by the cleat from the rail and sliding the palings up against it before nailing (See Figure 5).  Periodically check that the palings keep their vertical line by using a level or by measurement from both the top and bottom of the palings to the next post.

6.5  Palings may extend past the top or bottom rails , unsupported by a maximum of 150mm.

7. PAINTING

7.1  White is the traditional colour for painted fences.  It reduces the heat absorbed from the sun, highlights the contracts between light and shade,  complements floral displays and sets a positive boundary line.   Coloured fences are used to relate the fence to the house, brighten up a heavily wooded area, or liven up children's play areas.

For long fence life and infrequent repainting, use a good quality paint or stain.

7.2  Some hardwoods may leach unsightly tannin stain for the first 6 months when it rains.  In this case you could wait until the tannins wash out of the timber before applying the first coat of paint.

NOTE ON POST SETTING     back
Make sure  that the timber for your posts are Durability Class 1 or preservative treated to a level suitable for in - ground use (H5).  For proper drainage avoid getting concrete under the post.  Place the base of the post on a layer of gravel and back fill half the hole with gravel or well drained earth, tamping firmly every 200mm.  Fill the remainder with a dry lean concrete blend.  A mix of 1 part cement , 3 part sand, 5 parts gravel is good or allow 1 pre-mix bag per 1.5 posts.  Slope the top of the fill so that water will run away from the post.

FIGURE 4    back

A GOOD NEIGHBOUR FENCE  (Refer to Figure 7)  top

The decision to erect a boundary fence usually involves discussion as to which of the adjoining properties will face the palings.  One way to avoid neighbourly disagreement is to develop a fence style that looks good from both sides.

One easy way to achieve this is to fix spaced palings on both sides of the rails.  The privacy gained by a normal close -butted paling fence would be reduced, but the space between palings on both sides can be adjusted to give adequate privacy with an advantage that cooling breezes can still penetrate.

After erection of the fence frame the first row of palings is fixed, spaced along one side of the fence rails.  Spacing could be varied to improve final privacy. For example, 60mm spacing could be used for palings 100mm wide.

The second row of palings is then fixed to the other side of the rails so that the view through the spaced palings is blocked.  If more privacy is demanded then the paling on both sides could be spaced 40mm.

HOW TO SHAPE A ROUNDED ARCH  ( Refere to Figure 8)    top

Determine height of arch (1/5 of panel width is recommended) and mark down from top of panel YY line on diagram.  Mark midpoint of panel width (M on diagram) for top point of arch.  With an offcut the length of half the panel width , rotate from point M to intersections with YY line.  Mark intersection points (F on diagram).  Drive nail into F and M points half way into panel.

Tie string to one F point,   loop over M point and with string line taut tie to the other F point.

Remove M nail.  Position pencil in string loop and starting at one Y point, keep string taut at all times, trace out the arch ending up at the other Y point.

For a reverse arch - position M point on YY line and F points on top of panel (marked XX).

Arch is then traced from one X point to other X point.  

The best effect is achieved with equal width panels.

GATES AND ENTRY WAYS  ( Refer to Figure 9)   top

One of the most important considerations in developing your fence is to determine the details of the gate.  Careful thought must be given to both its design and location, which should be established by understanding clearly  the foot traffic pattern you want to create.

The visual impact of the gate is an important consideration.   Should it blend into the fence or send a definite message of welcome?  Is the gate entry formal or informal?  Should the gate provide  a strong design statement of its own?

The dimensions of the gate will be determined by the height of the fence and the width of the walkway it serves.  Be sure to make it wide enough to allow garden furniture, lawn-mowers and wheelbarrows to pass through.  Also, the gate should swing in onto your property, not onto the street.

Information sourced from TRADAC Home Improvement Guide.
(Timber Research and Development Council)

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