by Kim and Linda Katwijk
Stainless steel cable railing is low maintenance and
long-lasting. It's also fairly easy to install: Horizontal
cables are strung through holes drilled in railing posts and
tightened with cable studs — fittings that grip the end
of a cable run and allow it to be tensioned —until they
"sing." With its open, airy design, cable railing virtually
disappears, providing an unobstructed view and a clean,
My company specializes in building decks. Though cable railings
don't make up a large percentage of our work, we have seen an
increase in demand for them since they were approved in recent
versions of the building codes. Many customers ask about cable
railings but lose interest after learning that they cost almost
twice as much per foot as wood ones.
I buy cable in bulk and have the fittings I need made in a
local millwork shop. This substantially reduces my material
costs compared with using an off-the-shelf cable-rail system.
For convenience, however, you may want to consider one of the
available packages if you're doing only one deck (see "Buying
Cable and Posts
Cable comes in diameters of 1/8 inch to 1/2 inch, in 1/16-inch
increments. The sizes most often used for residential
applications are 1/8 inch, 3/16 inch, and 1/4 inch. With very
large posts — say, 10-inch-diameter logs — the
larger 1/4-inch to 1/2-inch cable should be used, to balance
the look of the railing. For commercial applications, 3/16 inch
is the smallest size allowed, but 1/4 inch is recommended. In
my area, 3/16-inch cable runs around 80 cents per foot when
bought in 100-foot rolls.
Posts can be made of a variety of materials, such as wood,
powder-coated steel, and powder-coated aluminum (Figure 1).
Cables should be spaced no more than 31/2 inches apart, so that
a 4-inch sphere can't pass between them (code requirement).
This means there are at least nine cables on a 36-inch-high
residential railing, and since each cable exerts roughly 300
pounds of tension, the posts need to withstand a minimum of
2,700 pounds of pull. Posts require stout mounting plus a cap
rail that spreads the load out from the anchor posts to the
intermediate posts (Figure 2).
Figure 1. Although wood is the most common
material for posts, powder-coated steel and aluminum are
clean-looking alternatives and can be engineered to withstand
the forces involved with cable railing.
Figure 2. Because the cables exert a
tremendous amount of tension on the end posts, it's critical to
mount the posts firmly to the framing, and brace between them
with a subrail that's capable of withstanding the
Most wood 4x4 posts can withstand these pressures. Because
cedar is so soft, though, you must use wider washers at cable
terminations to prevent the cable from pulling through —
and you should consider using larger posts, such as 4x6s or
Steel posts can be 1-inch-by-3-inch flat bar,
2-inch-by-2-inch-by-3/8-inch angle, schedule-80 pipe, or
1/4-inch walled tubing. With all steel posts, you need to use
sleeves of rubber, nylon, or stainless steel to separate the
cable from the steel and prevent wear. Aluminum posts of the
same dimensions can be used, but 2-inch-by-2-inch angle must be
beefed up to 1/2-inch thickness.
Do not attempt cable railing with solid composite posts, as
they will warp when the cables are tightened. Composite or
plastic sleeves that fit over a wood post are fine.
You can use single-posted (Figure 3) or double-posted (Figure
4) corners. Post spacing should be determined according to the
strength of the top rail, which — according to code
— needs to withstand 200 pounds of pressure in any
direction (plus help spread out the tension from the cables to
the other posts). Most railing materials are limited to 6 feet
or less, though with engineering, steel railings can exceed 6
Single Post Double End
Figure 3. There are two ways to handle a
single-post corner (left). One is to drill a curved hole
through the post (A). Because there's a lot of tension on the
inside corner of wood posts, a hardwood like ipe is recommended
over soft cedar or pine for curved-hole corners. The second
method is to terminate two cables at the post (B). For the
cables to exit at about the same height, one of the stud holes
must be drilled at an angle so it doesn't intersect the other
Double Corner End Posts
Double Corner Posts With Pass-Through
Figure 4. For double-post corners, you can
either set the posts within 4 inches of each other and
terminate the cable at each post (top) or run the cable through
both posts (bottom).
In most cases, the rail can span a greater distance than the
cables. The smaller the cable, the closer together the posts
need to be — no more than 36 inches between posts for
1/8-inch cable, 42 inches for 3/16-inch cable, and 48 inches
for 1/4-inch-diameter and larger cables. If you want a more
open look, you can avoid placing full-sized posts midspan by
substituting "stays" — thinner pieces of steel, aluminum,
fiberglass, or wood. The cables run through holes drilled in
Because long runs are harder to tension, I try to avoid
straight runs of cable longer than 80 feet. For runs that have
one or two 90-degree corners or up to four 45-degree corners,
40 feet or less is the rule of thumb. End posts need to be
spaced away from the building (Figure 5) to allow for
tightening the cable. When the face of an end post is exposed,
the ends of the studs are covered with caps that can be removed
for subsequent tightening (Figure 6).
Figure 5. Space end posts away from the
house to leave room for tightening the cables with a
Figure 6. A removable cap protects people
from the ends of the cable hardware while allowing for
When using wood posts and rails, I order all the railing
components before building the deck. If I'm using a welded
steel or aluminum frame whose dimensions can't be easily
changed, I order it after the deck is built. I like having the
flexibility to make changes in the deck framing without
worrying about the railing being exactly right.
The machine shop I use makes the cable studs from 4-inch
lengths of 1/4-inch 303 stainless rod. The shop drills a
1/8-inch hole down the center of one end to a depth of 1 1/4
inches, and threads the other end for 2 1/2 inches to take a
1/4x20 nut. The stud slides over the cable and is swaged, or
crimped, with an H.K. Porter swaging tool ($110; 919/362-1709,
www.cooperhandtools.com). Swaging makes a
strong, permanent connection (Figure 7).
Figure 7. A swaging tool (top) and a cable
cutter are the only special tools required. A cable cutter
multiple steel strands, and a swaging tool crimps connectors
onto cables for a permanent connection.
Alternatively, the Atlantis Rail System uses a mechanical
swaging that is an integral part of its universal turnbuckle
(Figure 8). Its ball joint and flange mount allows it to be
used for straight runs, turns, or stairs. Tightening a cap nut
secures the cable — no swaging tool needed, just a
wrench. The turnbuckle screws to the inside of the post, so it
can be installed tight to the building. The screw attachment
also saves time that would otherwise be spent drilling the end
posts. Though it costs about $14, this is the only commercial
stud I would use.
Figure 8. The author's favorite commercial
cable stud is made by Atlantis Rail Systems. A cap nut and
bushing eliminate the need for a swaging tool, and the flange
mount allows the stud to work at a variety of
For short runs — straight runs up to 40 feet or runs of
less than 20 feet that have one corner — studs aren't
needed at both ends. Instead, one end (usually on the far side
of the last post) is anchored with a swaged cable stop and
washer (Figure 9). Cable stops, which are available from any
professional fastener supply shop, are simple
1/2-inch-by-1/2-inch aluminum tubes with a hole sized to fit
the cable. For the stops, I drill a 3/4-inch-diameter hole 3/4
inch deep, then continue through with a small hole sized for
the cable. If the posts are ACQ-treated lumber, I make sure to
use stainless steel stops.
Figure 9. Studs and stops end the cable
runs. Stops are simple aluminum rings that are swaged onto one
end of the cable. Used with a washer, they resist the tension
applied by the stud. The author has studs made locally from
stainless steel rod; they're swaged to the cable and tightened
with a nut.
Preparing Posts for Cable
The first step in installing a cable railing is locating the
posts and making sure they're spaced to support both the upper
railing and the cable. The post locations dictate how to drill
the posts. For example, single-post corners get holes that
curve, while double-posted corners are drilled straight
through. Posts at stairs need angled holes.
I drill straight through most posts, using a bit that's 1/16
inch larger than the cable size. To drill accurately, I use a
simple jig made from a piece of 1x4 the height of the posts,
with guide holes where the cables are located. I use a
Milwaukee Pathfinder bit to drill the curved holes in
single-post corners; I start these holes from each side and
join them in the middle. Milwaukee no longer makes Pathfinder
bits, but Bad Dog Tools (800/252-1330,
tools.com) has similar ones (Figure 10). Single posts on
45-degree corners are mounted at 22.5 degrees and drilled
Figure 10. Curving holes are made possible
with Rover bits by Bad Dog Tools.
End posts need two-step holes to fit the cable stud, washer,
and nut. I use a 5/8-inch Forstner bit to drill a hole about 2
inches deep for the washer and nut (Figure 11). I center a
1/4-inch bit in the 5/8-inch hole and drill the rest of the way
through for the cable stud. (The Forstner bit makes an
indentation in the center so you can line up the 1/4-inch bit.)
It's important for the larger and smaller holes to line up,
because there's little room for a 9/16-inch washer and the
cable stud to align.
A two-step hole makes room for a socket
wrench. The cable and stud enter the opposite side of the post
through a smaller hole, and the nut used to tension the cable
is buried inside a 5/8-inch- diameter hole that also
accommodates the socket.
To find the right angle for drilling the stair posts, I use a
6-foot level, a Speed Square, and a torpedo level (Figure 12).
After cutting a small angle block for guiding the drill, I make
a hole halfway through the post with a 6-inch-long drill bit;
then I remove the guide and continue to drill through.
Figure 12. A long level on the tread noses
establishes the stair pitch, and a Speed Square, held level,
measures the stair angle (left). Use the angle to make a simple
guide block for drilling cable holes in stair posts and newels
If the stair post is going to be used as an end post, it will
also need a two-step hole to accommodate a cable stud or stop.
This can be tricky to drill. I use the angle block and a
Forstner bit with a drill stop mounted 2 inches back from the
cutting head. I start drilling with the bit vertical, then
carefully tip it back to meet the guide block and continue to
drill until the hole is 1 1/2 inches deep.
Capping and Cabling
Once all the posts have been installed, the top rail is fitted
between them to resist the tension when the cables are
tightened. The decorative cap is then installed continuously
over the top rail and the posts.
Cable comes on a large spool, which I mount on a spindle so
that it feeds easily from post to post. It's usually best to
set up the spool so that it feeds straight into the end post
— generally an end post that's not against the house.
Before threading the cable, I wrap the end with tape to keep it
from fraying on its journey through the holes. A $24 HIT Tools
22WRC75 cable cutter (909/974-0369,
www.hittools.com) cuts the cable cleanly.
Once the cable is fed through all the posts, I swage a cable
stud or a stop to its end.
The next step is pretensioning, or stretching the cable tight
before putting on the end stud (Figure 13). If you skip this
step and rely only on the threaded studs for tightening, you
may run out of thread before the cable is tight enough. Then
you'll have to cut off that stud — now expensive scrap
— and swage on another.
Figure 13. To pretension the cable before
final tightening, the author uses locking pliers to grip the
cable, and wedges to stretch it. He does this at several spots
along a run, particularly at corners.
Pretensioning is done with locking pliers, scraps of wood or
composite decking slit to fit over the cable, and wedges.
Working back from the first end post, I pull the cable
hand-taut and slip a piece of wood over it on the pull side of
the post. With the locking pliers, I gently grip the cable
right behind the block. Then I drive the wedges between the
block and the post to tighten the cable. Next, leaving the
pliers and wedges in place, I jump ahead three or four posts
and repeat the process. I pretension at every corner and
typically use four or five pairs of locking pliers in a
With the cable taut at the last post, I cut it to fit in the
stud so that there's just enough thread left to engage the nut.
I swage the cable stud, slip it into the end post, and tighten
the washer and nut. I install the rest of the cables the same
Once all the cables have been pretensioned, it's time to fully
tension each one. There is a correct sequence to this: Start
with the center cable, then tighten the remaining cables by
alternating above and below the center cable (Figure 14). All
cables should be of uniform tension, with no sag. Each should
sound the same note when plucked.
Figure 14. Because the top and bottom of
the posts are braced, tightening starts in the middle. Tighten
the center cable enough to remove sags, then alternate between
the cables that are directly above and below. When properly
tensioned, all of the cables should sound the same
The final step is to cover the holes in the end posts. I rip a
1/4-inch-thick by 11/2-inch strip of the same material as the
post, cutting it long enough to hide all the holes. This I
attach with three stainless steel screws, for easy removal in
case the cables need tightening.
Kim Katwijk builds decks in Olympia, Wash.
Linda Katwijk assisted with this article, which was adapted
with permission from Professional Deck Builder