| Market Guide for Purchasing a Gate
Contract
A good contract will cover most aspects of an installation.
Important details to look for are: A description of the work to
be performed, responsible party for different aspects of the job,
work schedule, warranty information, work authorization (permit)
information, proof of insurance, payment terms, structural settling
and concealed conditions clause, and proof that the Contractor
is licensed by the Contractors’ State License Board.
Contractor
Your contractor must be licensed, bonded and insured,
and have compensation insurance for his employees. A contractor
can easily supply you with proof of all the above, so don’t
hesitate to ask. You will usually get two out of three of the
following qualities in a contractor: price, quality, and timeliness.
Bid Comparison
Start with a reputable, well-known firm. Obtain
a bid that is all-inclusive and then have other contractors bid
on the same items. Compare "apples to apples". This
is a good way of leveling the playing field. The lowest bid is
not always the best bid.
The Complete Job
Job site safety, gate drawing, site plan, soil stability,
posts, footings, grading, gate, electrical and communication supply,
entry system, fire medical emergency lock, gate configuration,
gate operator, system power and communication lines, exit loop,
safety loops, photo electric eyes and other safety equipment,
lighting, site cleanup and restoration. All these items will be
discussed in the following paragraphs:
Job Site Safety
The job site has to be safe. All excavated areas
need to have cones or barriers. Protruding reinforcing bars, "rebar",
need to be plastic-capped. All garbage has to be cleared away
and all dangerous areas cordoned off.
Gate Drawing
The purpose of a drawing is to see the gate as it
would appear when finished. It should include any posts, columns,
and lighting. It is also good to see the side-to-side slope of
the road, as it would appear under the gate. This is especially
important if you have a lot of slope. The width of the road should
also be included. A gate drawing is usually required when obtaining
a permit.
Site Plan
The site plan is important for showing the location
of both the gate and operating equipment. A good plan will show
where all the wiring is buried and is useful for future repairs
and any excavating you may want to do later. A site plan is usually
required when obtaining a permit.
Soil Stability
If the soil is not stable there is a good chance
your gate will sag. Soil conditions are the first thing to look
at before you begin your project. If soil is not solid or has
major clay content you will need additional structural support.
You may need a grade beam or outriggers. Grade beams are concrete
beams that connect posts or columns together below grade. Outriggers
are metal arms that extend out in the two directions the gate
swings and are anchored in concrete. Post-holes have to be square
or the swinging motion of the gate will eventually enlarge the
holes and your gate will sag.
Footings for Columns
Concrete footings are required if you plan on installing
columns. The column footing needs to be installed at the time
of the gate installation. Footing size is determined by column
size and soil condition. The footing should be at least 18”
deep and be at least six inches wider than the proposed column
on all sides. The footing should have a rebar cage with vertical
rebar for the column. It is always advisable to connect footings
together with a grade beam.
Underground Service Alert
Make sure that either the contractor or you call
for an underground utilities check before excavating. In most
areas this removes liability if the contractor should cut through
a buried utility line. The various utilities come to your job
site and mark all underground utilities, usually at no cost.
Posts
Gate posts support the weight of the gate. The posts
can either be decorative (flank the gate), or be imbedded inside
the masonry columns. Imbedded posts are set in the middle of the
column footing and are used to hold the hinges, equipment vaults,
lighting, and other accessories. Gate posts should be at least
5 inches x 5 inches and set 36 inches below grade. The minimum
width of the hole should be 24 inches x 24 inches and be filled
with a rebar cage and concrete. The holes should be square to
prevent loosening by the gate’s swinging action.
Grading
Some sites are flat. Those that are not may need
grading. Water flow should be considered when grading. All added
road base has to be compacted.
Gate Construction
Heavier gates have a tendency to last longer. Where
hollow tubing is used it should be of a heavy gauge. The frame
should be of at least 1/8 inch wall thickness and stakes should
be at least 1/16 inch thick. The gate must have weep holes to
allow trapped moisture to vent or the gate will rust from the
inside out. All weld slag must be removed before painting or powder
coating. Removing slag is a tedious process. If not done thoroughly,
it is a major detriment to the longevity of a gate. Since paint
does not get into all the tiny spaces surrounding the slag, it
later falls off leaving a bare spot where rust begins. You can
tell good workmanship by how smooth the finish feels when you
run your hand over it. Check the areas around welds, and check
several gates built by your prospective contractor for this quality.
Gate Material
The most common gate material is iron (or steel),
with aluminum becoming increasingly more popular. Sculptural Gates
can also integrate unique materials into the design of your gate,
such as wood, glass, or exotic metals.
Steel gates provide a stronger “feel”
for your entryway and are less prone to damage if impacted. With
currently available coating technologies, such as galvanizing
and powder coating, decay due to rust is virtually eliminated.
In addition, more embellishment choices are available in steel.
Gates can also be fabricated from aluminum. The
advantages of aluminum are corrosion resistance and lighter weight.
Corrosion resistance makes aluminum an attractive choice for gates
that will be located in harsh environments. Lighter weight means
that less rigorous structural support will be required for the
installation. Aluminum can also be powder coated, so a wide variety
of colors are available.
While wood, glass, and exotic metals provide a beautiful
presentation for your gate, they should be integrated into a steel
frame to support their weight. In most cases the gate is fabricated
so that the unique material is easy to replace.
Powder coated finishes are superior to enamel and
can last up to 15 years. A good enamel paint job will last up
to six years. Single coat paint jobs, also called primer paints,
last only two years at best and should be avoided. Galvanization
should be considered if you live near salt water. You may powder
coat over galvanization if you prefer a different color.
Electrical and Communication Lines
The National Electrical Code calls for electrical
lines to be buried at least 18 inches underground. Unfortunately
we often find these more shallowly placed. It is not a pleasant
experience if you hit a power line. Even if you don’t get
shocked you will endure a costly underground splice.
Power and communication lines must be in separate
conduits, for safety and to prevent noise on your telephone or
intercom system. The conduit should be larger than necessary for
easy wire pulls and future repair. The wire should be large enough
to deliver the needed current after line loss. Line loss is a
voltage drop that happens whenever power is delivered over long
runs. Almost all underground conduits fill up with water. Use
wire with appropriate insulation to hold up to these adverse conditions.
Most single gates (one operator or motor) need 10
amps at 110 volts AC. Consult an electrician before laying long
runs underground so that you get the right gauge of wire. Splice
or "Christy" boxes, should be installed at least every
200-300 feet. Use high quality communication wire, preferably
direct burial cable installed in conduit.
Entry System
There are many entry systems on the market, many
of which are good, though some are more difficult to program than
others. Check with your installer on ease of programming. Determine
whether you need a simple keypad or one that communicates through
your telephone system. There is a large cost difference between
the two. Card reader units are used more in industrial applications
and multiple dwelling communities. Make sure the "Goose neck"
or pedestal mount is sturdy. The unit should not move when you
use the keypad. In certain applications wireless intercom systems
can be installed. These units either connect to your phone system
or require a separate base station for direct communication and
gate operation.
Video
Video cameras can be installed in your telephone
entry device and around your entryway. Video surveillance systems
can range from a single camera and display screen to a system
that monitors your entire property. Contact your installer to
determine the system that is right for you.
Fire / Medical Emergency Lock
Most municipalities require you to have a fire /
medical lock to allow emergency crews to enter your property without
damaging your gate or automation equipment. Make sure this item
is not left out of your installation; you will only have to install
it later.
Gate Configuration
In addition to standard slide and swing gates, other
proven options are available to help you overcome difficult terrain
conditions or space constraints. Uphill Hinge:
The uphill hinge mechanism causes the far end of the gate to rise
as it opens (to clear the upslope). The hinge end of the gate
will coincidently be directed towards the center of the driveway
(decreasing entryway width). Lift Gates: The
vertical lift gate rotates 90 degrees, vertically, to open. The
gate can be opened or closed by hand in the event of a malfunction.
The gate operator is rather large since it includes the counterweight.
Cantilever Gates: The cantilever gate is a slide
gate that is suspended in space, so no driveway track is required.
Cantilever gates are longer than traditional slide gates because
of the counterweight member.
Gate Operator
There are several ways to operate a gate. Swing
gates can use four types of operators. A swing arm operator, which
is a box, that sits off to the side and has an arm extending to
the gate. A ram arm is located on the gate and post and uses either
a hydraulic piston or a jackscrew-operated piston. A column mount
operator mounts on a wall or column to open the gate with a swing
arm style action. Underground operators are located by the hinge
and operate the gate from below grade.
The simplest to service and install is the swing
arm operator. The advantage of the ram is that it is smaller and
takes up less space. The column mount operator uses less space
that a traditional swing and does not require a niche in the column
to operate. The underground operator is the most expensive but
is very attractive in that you see no equipment. The swing arm
is usually the fastest of the operators. The swing arm units also
handles a gate very smoothly and slows down toward the end of
each cycle. Some ram arms do not have a slow down feature and
the gates have a tendency to shudder at the end of each cycle.
This shuddering is more pronounced when the gate is longer as
in a single swing gate installation.
Slide gate operators are commonly installed at the
end of the gate in the closed position but can also be installed
at the end of the gate in the open position. In the first configuration
a chain is attached from one end of the gate to the other (near
the bottom) and passes through the operator, which shuttles it
back and forth. In the second configuration you do not see the
chain or any operating equipment near the gate. Sliding gates
are more hazardous than swing gates and should be equipped with
appropriate safety devices.
Either type of gate operator is available in 110
volt AC or low voltage DC. The DC powered gates can run off low
voltage transformer or solar panels. Solar installation requires
more maintenance than an AC powered system. Quality operating
equipment will generally last 12 to 20 years before it needs to
be replaced. Most installations use a built-in timer that closes
the gate after a set period of time
Exit Loop
An exit loop is wire that is either buried beneath
the driveway or cut into the concrete or asphalt. It is located
behind the gate. Locating it far from the gate is best. A vehicle
triggers the loop, which acts like a big metal detector and opens
the gate, allowing the vehicle to exit.
Loops can be a weak spot in many gate systems. All
loop connections must be soldered and any underground connections
completely waterproofed in order to avoid problems. The size,
shape, and number of turns of wire in the loop will determine
the sensitivity. Loops cut into asphalt or concrete should be
1" or more deep. Those buried in earth or gravel should be
4-6 inches.
Reversing Loops, Edge Sensor Switches, and Photo
Eyes
Reversing (Safety) loops are buried or cut in the
pavement in front of and behind a gate. They prevent the gate
from closing on a vehicle in its path should it stay there past
the "momentary open" timer setting.
Edge sensor are long strip switches as found on
elevator doors They are used halt gate motion if an obstruction
is encountered.
Photoelectric "eye" and safety loops are
often used in conjunction with one another. A single photo eye
may be used on a slide gate to hold the gate open in case a vehicle
stays too long in its path or reverse if a vehicle enters its
path as it is closing. Other "entrapment zones" created
by the gate (e.g., sliding behind a fence or wall) should be protected
by safety devices well.
Finally, all gates should be equipped with a warning
sign, visible from both sides, to prevent accidents and limit
your liability. For more information refer to our section on regulation
U.L. 325 safety guidelines.
Personal Safety & Underwriters Laboratories
Standard UL-325
By definition, automated gate systems are intended
solely for vehicular traffic. However, personal safety is paramount
to any automated gate system. For that reason, Underwriters Laboratory
developed UL-325, a voluntary standard whose primary intent is
to prevent entrapment or injury of people by automated gate systems.
UL-325 is not concerned about the gate contacting vehicles, only
the entrapment or injury of people.
Compliance with UL-325 means that you have a separate
walk through gate installed for pedestrian traffic, have sensors
and guards installed to protect people from entrapment areas and
pinch points, have slide gates constructed so that a 2-1/4”
diameter sphere cannot pass through critical areas of the gate
(and associated fencing), have operational controls located at
least 6’ from the gate, and have any other safety measures
installed that are deemed necessary for the specific application.
You should understand that automated gates are not intended for
pedestrian traffic and notify the Contractor if you choose to
have UL-325 safety features installed.
Lighting
Lighting often is located either on top of gate
posts or on top or on the front of columns. The best way to control
lighting is with a combination timer-photocell. The timer is set
to activate in the afternoon and has a photocell located between
it and the lights. Once the timer is activated, the photocell
prevents the lights from coming on until dusk. The timer shuts
off the lights at a predetermined time, (e.g., midnight). In this
way the lighting tracks the seasons and you do not have to keep
adjusting the timer.
Site Cleanup
A project is not finished until the job site is
thoroughly cleaned and restored to its former state. Special circumstances
should be discussed (e.g., hauling away certain debris). It should
be made clear whose responsibility this is. The contractor should
always perform ordinary clean up at the end of each day.
Summary
Sculptural Gates installs complete gated entryway
systems using the finest materials and methods. We work closely
with you to determine the best system for you, based on style,
functionality, and cost. Contact us to arrange for a no cost site
evaluation and cost estimate.
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