Along with providing security and privacy, a nice wood fence
can serve as a property's crowning design element. Leaving wood
outside in a wet climate like mine, though, borders on criminal
behavior — and so as a restoration carpenter working in
New Orleans, I've focused throughout my career on making
exterior wood last as long as possible.
Early in 2005, my best rot-prevention techniques were put to
the test when some past clients approached me about building a
fence on one side of their restored house. Natives of New
Orleans, these folks knew how fast things decay here and they
wanted something that would be around for a long time.
To prevent rot and discourage insects, I keep in mind five
simple rules whenever I'm building a fence — or anything
outdoors, for that matter.
1) Keep joints — which hold water — to a
2) Avoid applied moldings. They trap water and organic
material, the prime ingredients for rot and mildew.
3) Pooling — or sitting — water is much more
destructive than flowing water; if you can't properly shield a
joint, open it up so that water can move through freely.
4) If there are enclosed spaces like column wraps or boxed
beams, provide some form of ventilation to dry the
5) Seal all end grain.
Basically, my clients wanted a spindle section above a
vertical-board fence, dressed up with a trim board at the
bottom (see Figure 1). Complicating matters, they also wanted
fence panels between the posts.
Figure 1. The beveled
surfaces and drainage spaces on this fence prevent water from
pooling and promote drying.
Given the rough parameters, the first order of business was
picking a type of post. I like to use 21/4-inch hot-dipped
galvanized metal pipe because it holds up very well in our
climate. But my clients didn't like the pipe's appearance, and
wrapping it with wood wasn't in the budget, so the only option
was No. 2-grade pressure-treated 4x4s.
Lumber. We chose a clear-grade PT for
the rest of the fence; it's not as expensive as redwood or
exotics and it warps less and machines better than the other PT
I generally try, when using a lesser grade, to air-dry it out
of the weather and sun for at least a month. That way, I can
cut up the worst material and put pieces with bows, crooks,
twists, and checks in places where they'll be less
Also, despite what the lumber salesmen may tell you, .25-pcf
pressure-treated wood will rot above-ground in the Deep South,
so we used lumber with a .40-pcf treatment.
Fasteners and hardware. Stainless steel is my
preferred material for exterior applications. Grade 304 or 305
stainless is generally fine — unless you're near
saltwater, in which case you will want Grade 316.
After balancing cost considerations against expected longevity,
we settled on USP's MP34-SS connectors (800/328-5934,
www.uspconnectors.com) to fasten the fence
rails to the posts. The only nonstainless hardware that went
into this fence was a black powder-coated gate latch, installed
with stainless screws.
Laying out and setting the 4x4 posts was done in the standard
manner of setting batter boards and pulling a centerline
I spaced the posts 8 feet on-center and dug 2-foot-deep holes
with a 10-inch auger. I flared the hole bottoms by hand and
then filled them with several inches of coarse gravel for
drainage. Some fence builders, I know, object to installing
fence posts in concrete, but our "gumbo" soils down here make
it a necessity.
I put the two straightest 4x4s aside for the gate posts and
used the two next best for the end posts. I set the end posts
first, doming the concrete several inches above grade to shed
water. The posts were braced off in both directions while the
concrete set up. The next day I installed the remaining posts,
using string lines stretched between the end posts.
There are two things to keep in mind here: First, no matter how
careful you are, the fence won't be dead straight. If you want
it perfectly straight, you'll have to go with wrapped metal or
Second, concrete footings like the ones I used here are very
good, but if you want the fence to stay as straight as the day
you built it, you'll need to link the post footings together
with a small grade beam. This adds significantly to the
project's cost and complexity, but it's often a good idea,
especially for heavier fences built on wet soil.
I started assembling the fence sections by putting a 15-degree
bevel on the top of each horizontal member and drip grooves on
the bottom of the top rail. This would prevent water from
sitting on the surface and make it drip off instead of
following the wood (Figure 2).
Figure 2. The top of
every horizontal member gets a 15-degree bevel to shed water
and debris. Rain grooves on the bottom of the top rail break
surface tension so that water drips off instead of following
the fence to the bottom.
For safer and more precise cutting, I typically use feather
boards from Bench Dog Tools (800/786-8902,
www.benchdog.com) to hold the lumber tight
to the fence and table (Figure 3).
Figure 3. Feather boards
prevent kickback and help produce better-quality saw cuts and
dadoes. A sturdy magnet holds the shop-made wood feather board
on the saw's cast-iron table. The plastic feather board mounted
on the table in the miter-gauge slot and the vertical feather
boards on the rip fence are made by Bench Dog
Once all the pieces are cut, I prestain them, which saves a lot
of time down the road. In this case, the client coated
everything with reddish-brown semitransparent stain.
When the pieces were ready, I figured out the highest part of
the yard and added 2 inches. This would be the elevation of the
bottom of the fence and would keep the bottom trim board 2 to 5
inches above grade. I then used a level/transit to mark the
location of the horizontal rails on all the posts, so I could
install the angle brackets that would hold the fence
Next I sorted through all the shaped rails and placed the best
pieces toward the front, with increasingly twisted ones going
toward the rear. I cut the rails 1/2 inch short of the actual
measurement to obtain a 1/4-inch drainage gap on each
The spindle assembly on top of the fence came next. I juggled
the spindle spacing so that a common spacing would work in all
the post bays. And to hide slight discrepancies in the 8-foot
post spacing, I didn't place spindles against the posts.
I was able to get three spindles from a 3-foot-long PT
baluster. I put a 15-degree cut on the spindle bottom to
correspond with the bevel I made on the bottom spindle rail.
After laying the cut spindles into a jig I'd made, I screwed
them into the top rail (Figure 4).
4. The 2x2 spindles capping the fence are laid into
the jig and screwed to the rails with 3-inch-long #7 trim-head
screws. The tops of panels are predrilled and screws are
started to make final assembly easier (top). Keeping the
spindles away from the posts helps hide slight discrepancies in
the panel caused by warped posts and varying panel sizes
The fence boards started out as 12-foot 1x6s. After cutting
them in half, I turned them around and cut off both factory
ends at 5 feet 11 inches. Since they were already prestained,
the boards were ready for pilot holes — which, though
they are not absolutely necessary, make installation much
easier. Plus, level screws look better on the finished
Before drilling, I arranged the boards with the flat grain
pointing down, so if the grain lifts in the future it will
still shed water. Then I made a jig to drill the pilot holes
Figure 5. The screw
pattern on the first full-sized fence board is laid out by
hand, but then it becomes a jig for the rest of the boards when
the author screws registration blocks on one end and one side
(top). Smaller boards next to the post get their own jig. A WL
Fuller Co. tapered bit (401/467-2900,
www.wlfuller.com) does the drilling and
countersinking in one step (bottom).
Prior to installing the fence boards, I cut and applied 3-inch
strips of Colbond's Enkamat 7010 drainage matting
(800/365-7391, www.colbond-usa.com) to the fence rails.
Enkamat — a matrix of black spun nylon — creates a
slight drainage gap where two pieces of wood are placed
together (Figure 6).
Figure 6. A 1/8-inch gap
behind the fence boards — created by fastening Enkamat to
the rails with stainless-steel staples — keeps water from
being trapped (top). Similar gaps are left where the horizontal
rails meet the posts. The author fastened the L-shaped brackets
securing the rails with 11/2-inch-long #8 pan-head screws and
oriented them so that the brackets are hidden behind the fence
boards (bottom). Some rail ends were cut on a slight angle or
bevel to match warped or twisted posts.
To ease installation, I made a "sideways" story pole, marking
it out with the nominal board width of 51/2 inches, separated
by 1/8-inch gaps. With the story pole I could center the layout
so that both end pieces would come out about the same
I could also easily determine whether starting with full boards
on the ends and making the center board different would be a
better option, as it was with the gate.
Once the fence boards were ready for installation, I sorted
them for graining. The ones with the best vertical grain were
set aside for the gate; other vertically grained boards were
set aside for ripping into each bay's end boards. The rest were
arranged in agreeable patterns, with the best arrangements
placed toward the front.
Before installing the boards on the horizontal rails, I ran a
bead of Titebond III along each board's top edge. Then I slid
the boards into the dadoes and fastened them with 2-inch-long
#10 square-head screws.
Down here in New Orleans, Formosan termites are a serious
problem. If you attach any wood structure to the house, the
termite guys want a sighting gap, so you often have to get
creative. In this case I used 1/4-inch stainless-steel eyebolts
and 3/8-inch carriage bolts to attach the fence to the house
Figure 7.In the New
Orleans area, wood structures cannot be attached directly to a
house, so the author secures fence sections abutting the home
with stainless-steel carriage bolts that pass through eyebolts
into brass inserts epoxied into the framing. This method
prevents direct wood-to-wood contact and allows inspection
during annual termite treatments.
With everything straight and secure, I marked and cut off the
fence posts and installed copper-topped post caps.
The construction method for gates has become standard for me.
The perimeter and intermediate rails are made from 2x4s with
plastic biscuits and epoxy connecting the joints (Figure 8). I
prefer this method — even though I've used traditional
diagonal braces in the past — because it better matches
the rest of the fence and provides solid stock for mounting a
Figure 8. The gate's
mitered corners are assembled with 4-inch stainless-steel
screws, Lamello K-20 plastic biscuits, and two-part epoxy.
Ulmia miter clamps from Garrett Wade (800/221-2942,
www.garrettwade.com) hold the assembly
together while the epoxy sets. The author prefers an
intermediate rail to the more traditional diagonal brace
because it matches the rest of the fence and provides space to
mount the latch.
I actually started working on the gate frame immediately after
setting the posts, because I wanted the epoxy to fully cure
before the gate went into service.
Once the frame was complete, I used three 8-inch
stainless-steel T hinges to mount it. To give the gate a little
more pizzazz, I accented the front with a piece of canary wood,
which is a dense tropical species with distinctive grain.
Rot tends to get its foothold in any of several places —
fastener penetrations and areas that hold water rank high on
the list — but the most common starting point is probably
I protect end grain with DuPont Corlar 2.1 ST, formerly Corlar
two-part high-build epoxy is thick enough that it doesn't
totally disappear into the end grain, so I get a complete seal
with one coat. West System epoxy (866/937-8797,
www.westsystem.com) works, too, but it
costs more and generally takes several coats.
After applying the Corlar, I mixed up some DuPont Imron 2.8 HG
high-gloss polyurethane, formerly Imron 333 (DuPont,
reddish-brown and applied two coats to the same areas. The
color blended in with the stain pretty well.
I prefer Imron to regular paint because it dries fast enough on
a warm day that you don't need to wait between coats. Also,
since Corlar and Imron are part of the same system, Imron bonds
chemically to Corlar (Figure 9).
Figure 9. Designed
primarily for industrial applications, two-part coatings have
better adhesion and a higher percentage of solids than
conventional one-part paints. The author uses them to prevent
water from entering vulnerable end grain (top and middle).
Bending the handle on a foam brush makes coating the bottom of
fence boards easier (bottom).
Had it been my call, I would have used the same paint recipe on
the rail tops. This would have gone a long way toward
protecting these components, which get the brunt of sun and
I also recommended installing backer rod and caulking the joint
between the posts and top rail to shed water; in this project,
those tasks were left up to the owners. I like Dow Corning's
795 Silicone, but anything is better than nothing.
I can say with some pride that despite Hurricane Katrina's
105-mph sustained winds and even stronger gusts, which knocked
down fences, light poles, and traffic signs everywhere, my
fence came through unscathed. The only visible evidence of the
storm was a line about 3 feet up, a reminder of the weeks it
spent under water.Michael Davis is a restoration carpenter
in New Orleans.