How deep a hole ?

michael ark · #1 09/20/14, 05:22 PM

I am putting up a 16ft gate on my drive way it weighs 127lb. How deep does the 6x6 have to be to avoid problems with it in the future? Thank you for you help.

AmericanStand · #2 09/20/14, 05:42 PM

50 feet should do it.

AmericanStand · #3 09/20/14, 05:47 PM

Seriously no matter how deep you go if you don't support both ends eventually it will lean.
If you cant support both ends Id go 3 or 4 feet deep with a wire tieback to a anchor either the post before it or a dead block or spiral anchor .

Sawmill Jim · #4 09/20/14, 05:59 PM

Here we don't have loads of snow so I just use a nose wheel on the end .

CIW · #5 09/21/14, 07:08 AM

Michael,
Put one gallon of water in a bucket (8.8 lbs.) and hook a 6 ft. stick through the bucket's handle. Take the other end and hook it under the bumper of the pickup or the porch as such. Now go 1 ft up the stick from the bucket and pull up. then move 4 ft. and do it again. Its still the same 8.8 lbs. of water but the downward pressure is multiplied hundreds of times.
Although that 6x6 won't likely break off, holding your 127 lb. gate suspended out 16 ft. won't work by itself.
There are several ways to keep a gate hanging straight.
1) Build a structure over the gateway to support the gate from the latch side. You may have heard this called a "bow gate".
2) Build a counter balance behind the hinge side, such as a deadman or other structure built into the fenceline. Many times the gate post is left extended long and a guy cable is attached to the top and leads back to a deadman or post.
3) Dig a trench out from the gate post at least half wayinto the gateway, toward the latch side. In the trench, construct a leg to counter balance the gates weight. Most time this is done using a combination of steel and concrete. It is best to extend and connect to the latch post. It's often refered to as an "H" structure.
Even after building this structure, if the gate is to be open for any extended period of time, there needs to be a prop mounted in the ground for end of the gate to set on in it's open position.
If you don't employee these types of preventive measures, each time you open and/or close the gate it will loosen the pivot post, causing the gate to sag.
You can better see which method will work in your situation.

fordy · #6 09/21/14, 10:16 AM

Quote:

Originally Posted by michael ark

I am putting up a 16ft gate on my drive way it weighs 127lb. How deep does the 6x6 have to be to avoid problems with it in the future? Thank you for you help.

..............You'd be better served by using a 8 to 10 foot stick of 3 inch OD pipe ! Make your hole 4 feet deep and 12 inches in diameter , probably take 5 to 6 sacks of 80# sackcrete . The problem with using wood is that wood is soft , and will absorb moisture and compress and Bend depending upon the load it is supporting . Pipe doesn't bend , and is impervious to moisture and has a much longer life vs wood . , fordy

willbuck1 · #7 09/21/14, 11:49 AM

A 6 by 6 seems kinda light duty dor that gate.

Yvonne's hubby · #8 09/21/14, 12:10 PM

I have had pretty good luck with telephone poles about 10 ft long, buried 5' deep with a couple inches of quickcrete around it and leaving 5' out of the ground. I am also a firm believer in running a diagonal brace wire from the top of the gate post to the bottom of the first fence post in line with the gate post.

blanket · #9 09/21/14, 12:18 PM

for a 16' gate I use a 10'- 12"-14" post made from a utility pole buried 5' in the ground, diagonal wire braced to another one 8' away with a 4"x4" horizontal brace between them. Gate will still sag unless other end is supported

haypoint · #10 09/21/14, 04:49 PM

A lot has to do with soil type. Some soils harden down and hold a pole. the clay I have will not support much weight.
But if you put a post in about 4 feet and have a wheel to support the gate, you should be fins. Without the wheel, run a HT wire brace from the top of your 6 x 6 back 12 feet to the base of the next post and back to the topo of the gate post. Use a stick to twist the wires, tightening them.

plowhand · #11 09/21/14, 07:17 PM

Quote:

Originally Posted by blanket

for a 16' gate I use a 10'- 12"-14" post made from a utility pole buried 5' in the ground, diagonal wire braced to another one 8' away with a 4"x4" horizontal brace between them. Gate will still sag unless other end is supported

This hits it on the head.......just generally you always need to bury 1/3 of a post for stability....It may take more in land where the ground freezing can heave post up and loosen them...I cement mine in....just used portland, mixed with sand 1 part cement 2 part loose sandy soil, fill the hole part way with water...shovel in mix and keep dropping in chunks of brick and cement I wanna get rid of as I fill the hole

In years to come, if your post leans in...a deadman, turnbuckle, and cable can pull it back upright......can get in the way though

DaleK · #12 09/22/14, 09:56 AM

Don't put it in straight now. Give it a bit of room so it straightens as it sags. I've had good luck putting them in fairly crooked, filling, then straightening them in place with the loader and re-tamping.

wogglebug · #13 09/22/14, 03:30 PM

Don't do it. Put in a 18' or 20' gateway, and put two 9' or 10' gates. To make things easy, put in a cattle grid on one side, so you can leave the gate open almost all the time on that side.

DEKE01 · #14 09/22/14, 03:44 PM

I do not know how deep your fence post hole should be, but I would like to thank you for not having a comma after deep and a hyphen between the a and hole.

Rustaholic · #15 09/22/14, 06:49 PM

I agree with the pipe instead of the treated 6X6.
I would go with a 4" pipe and put it five feet in the ground with the concrete.
A good cable from the end of the gate back to a welded loop on the pole top that has a good turnbuckle in it.
Another cable with a turn buckle would go from that welded loop cap up the fence at least as far as the gate is long.
Make sure that post is well anchored too.

I do not like doing things twice.
That is why my mail box post is a utility pole buried six feet in the ground.
I started the hole with the clam shell two handled type of post hole digger then I switched over to one of my pipe handled ones that you turn into the soil and pull straight up.

When I had my Ford 3500 Industrial tractor and was plowing snow with the bucket and back blade the back blade caught that post and stopped the tractor dead in it's tracks.

Today was another day I was happy to have my old 1950s large heavy metal mailbox. When I order things I have never had so many boxes all delivered on one day before. That mail delivery guy did a great job fitting it all in there. I really should have taken a picture.

spur · #16 09/22/14, 09:17 PM

Generally you plant a post 1/3 of it's length in the ground. An 8' 6x6 would be in the ground 32". Another thing you can do that is real simple. Plant your post and cement it in. On the post where you latch the gate nail a short piece of treated 2x4 where your gate touches the post so the gate sits on the top of the 2x4. The 2x4 will bear most of the weight and will put a lot less stress on the post where the gate is hinged and it won't sag much at all. It will also help if you can put a wheel on the latch end so you don't drop the gate and all of it's weight on your hinge post.