Structural Diagrams & Articles

Outriggers are recommended on gate installation where soil conditions are unstable such as clay, sand, and loose soil. Bi-parting gates should have outriggers or a grade beam to keep their alignment. Many installations need this type of support when the gate exceeds 250 lbs.

Soil conditions requiring this type of installation are prevalent more often than people realize. Outriggers are important on driveways that are cut into a hillsides where the hinge side of the gate is by the downward side of the hill. You may be able to avoid the use of outriggers by increasing the depth of the post hole from 36" to 48" - 60".

Footing sizes are related to column sizes and soil condition. The softer the ground the wider the footing should be. It is a common mistake to construct a column with footing that can weigh up to 10,000 lbs on a 3' x 3' foundation in unstable ground. A small footprint will concentrate the weight with the end result of sinking or tilting. When encountering clay or soft ground, it may be a good choice to install a grade beam between columns.

It has become normal practice for many designers and architects to specify a 3' x 3' x 3' footing. This will work well only in very stable stable soil conditions. We have found that most footings are better off being 18" deep with a much larger footprint. This has the effect of spreading the load and helps to prevent tilting toward the gate. Offsetting the footing so that more area is concentrated under the hanging direction of the gate can be an enhancement.

Soil with a large clay content can seem stable in the summer. During the winter the clay softens

Internal column skeletons are typically made of 5" x 5" tubular steel. The hinge arms are typically 4" x 4" tubular steel and can be mounted to the end of the arms. There are two types of hinges generally used on driveway gates; block hinges and flange bearing hinges. The flange bearing hinge is the preferrable choice as it allows adjustment which is especially critically for bi-parting gate installations.

Lighting fixtures are common on both the top and front of gate columns and should be accounted for when constructing the skeletons.

The gate should be hung prior to applying any masonry which assures the gate placement is correct before the columns are built.

Grade beams and modified foundations are used when soil conditions are not stable enough to support columns or gates. There is always a small amount of movement in columns due to the large amount of concentrated weight on top of foundations that have a relatively small footprint. A column can weigh 4,000 - 6,000 Lbs (1814 – 2700 kg) and the foundation can weigh another 4,000 Lbs. With 8,000 - 10,000 Lbs. of material sitting on top of 3 square feet (one square meter) of area, there is high probability for settlement.

Grade beams are highly recommended for bi-parting (double) gates as maintaining alignment is much more critical than single gates. When bi-parting gates are hung from columns, there is a high probability they will become misaligned within a short period of time.

Foundations can be modified to prevent settlement by altering their size and depth to accommodate soil conditions. If you are in doubt of your soil conditions you should consult with a soil engineer.

Typical Wiring Diagram for Gate Automation: Gate Operator, Keypad, Exit & Safety Loops

Typical Wiring Diagram for Gate Automation: Gate Operator,Timer, Keyswitch with Entrance, Exit & Safety Loops.

The timer and key switch are optional. The key switch allows the entrance loop to be engaged manually while the timer allows a 7 day program to engage the entrance loop at any given time and days of week. The key switch is often used in conjunction with the timer to deactivate the entrance loop at will. On operators with dedicated plug-in loop detector modules, you can add a separate loop detector for entrance loops and connect it to the key (trigger) input on these units.