How to Make and & Install an Adjustable Length Gate for a Driveway

This 16ft. gate has been in service over 15 years with no maintenance except periodic painting.

This light weight gate was constructed to replace a heavy commercial one that kept sagging and that put too much overhung load on the hinge post. It is relatively light weight and was designed in such a way that allows for a measure of future sag and for a little variation in the distance between the support post (hinge end post) and the post where the gate lock is located at the other end. This gate is easy to construct, looks good and the one in the photo has been in continuous service for about fifteen years.

With some commonly available materials, a wire welder and some sweat equity you can crank out a gate to suit that driveway or rural access. The following outlines a method of constructing a gate similar to the one in the photo. The gate photo is of a 16ft. width, and the gate outlined in the instruction drawing is for a nominal 12 ft. opening. If you need a different width just lay out the pieces on a concrete floor and adjust to suit your requirement. Happy fabrication!

Things You'll Need

• 2 pcs HSS (tubular steel) 1 x 1 X 1/16 wall X 20ft.
• 1 pc HSS 3/4 x 3/4 x 1/16 wall x 2'-0 in long
• 1 pc 3/8 in dia. bar x 10ft
• 2 - 4in square heavy butt hinge
• 1 pc angle iron 1 1/2 x 1 1/2 x 4in long
• 1 pc flat bar 1/8 x 2 x 3 in long
• 1 good lock with extra keys
• Hacksaw
• Wire welder
• Welding hood
• Leather gloves
• 4in disk grinder
• Wire brush
• Safety glasses
• Framing square
• Tape measure
• Electric or battery powered drill
• 3 cans good exterior enamel spray paint
• Piece of 100 grit sandpaper
• 1/2 in dia drill bit
• 2 - 3/8 in dia. lag bolts x 2 in long for latch angle
• 6 - 3/8 in dia lag bolts x 2 1/2 in long for hinges
• 2 - sack of ready mix concrete
• Post hole diggers
• 4ft. level
• shovel
• 1/4 in dia. drill bit
• 2 - pressure treated posts x 8 ft.
• Power saw, hand saw or chain saw
• Socket set with ratchet and/or adjustable wrench

Instructions

1. Set the hinge end post in the ground by digging a hole from 30 in to 36 inches deep. Set the post in place, rotating the faces so that they are square with the drive being gated. Pour in the sack of dry concrete mix and a small bucket of water. Use a narrow shovel or even a piece of 2 x 4 to sort of mix up the water and concrete. Ground moisture will actually set it up if you will wait a few days. Back fill the hole with the dirt that was removed. Compact this dirt every six inches of fill with the end of a 2 x 4. Make sure that the post is plumb before leaving it to set up. The concrete for this post can be setting up while the gate is being made.

2. 

   Cut the steel tube parts for the gate assembly. Lay out the parts on top of a flat surface such as a concrete shop floor. Fit these up and tack weld together. After verifying that parts are square and in the correct position, fully weld around all pieces. Drill out three 1/2 inch dia. holes in each outstanding leaf of each of the two butt hinges. These will receive 3/8 in dia. lag bolts.

3. 

   Make the sliding tube assembly. File off all sharp edges and burrs since this piece will be handled often when locking or unlocking the gate.

4. 

   Make the clip angle assembly. This will bolt to the gate.

5. Paint the gate and clip angle the color of your choice. Before painting clean all weld joints with a slag hammer and a wire brush.

6. Mount the gate to the hinge post after the post concrete has been setting up for 36-48 hours. After deciding how high you want the top of the gate above grade, mark the hinge holes locations on the face of the gate hinge post. Pre-drill these six holes with a 1/4 in dia. drill x 2 1/2 inches deep. Make sure that the top tube of the gate assembly is level or slightly above level when these holes are marked. By setting the tube slightly above level on the gate latch end you are allowing for any future sag of the assembly. Now bolt both hinge leaves securely to the hinge end post using a socket set and ratchet or adjustable wrench and the 6 - 2 1/2 in long lag bolts.

7. 

   Now that the gate is mounted on the post, select the position of the latch end post. When digging the hole for this post do not push the sliding tube assembly all of the way into the top tube of the gate assembly. Slide it out say 6 to 8 inches and set the post according to this. This allows you to slide the tube back or forward to assist in locking the gate. Dig the post hole and set this post just as the hinge end post was done.

8. 

   Swing the latch end of the gate to the newly set post and determine the location that the clip angle is to mount. Set the top of the slotted hole in the angle about 1/4 inch above the hole in the plate on the sliding tube. This assures that there will always be enough dimensional liberty to place a lock on the two parts. Mark the holes on the post to match those on the clip angle. Pre-drill these 1/4 inch dia. x 2 inches deep in the face of the post. Now bolt this angle in place using the two 2 in. long lag bolts.

9. 

   Touch up the gate paint if it was scuffed or scratched during assembly to the posts

10. Saw off the top of the posts to a suitable height - your choice - above the level of the gate. Posts can be sawed off at an angle to shed water if you wish.

11. 

    As an option an adjustable stop can be mounted either side of the gate on the hinge post end to limit the travel when the gate is resting open.

Tips & Warnings

• As an option a stop can be mounted either side of the gate on the hinge post end to limit the travel when the gate is resting open. This can also be accomplished with post or pipe set in the ground at either side of gate close to hinge post.

• This gate width can be varied to suit different lengths just by lengthening or shortening the longest members.

• The hinge end post in this how to is wood. If you want to use a steel post then weld the hinge leaves to your steel post in the shop. The entire assembly will have to be blocked up while the concrete mix sets up if a steel post is used, unless the hinge leaves are bolted to the post.

• Make as many lock keys - with some extras - as there are people using the gate.