Fence post installation issue


I'll try to keep this short. I recently had a privacy fence installed by the builders of my house and I do not feel that they've done a good job. I think they were lazy and didn't dig a deep enough hole and then just poured a couple of bags of concrete on top and are hoping they can get away with it.

The thing is, it's pretty hard to tell if they dug deep enough without, you know, digging up the entire post. Luckily, since they only installed one section of fence, the end post is still "open" so that I can finish the job myself once the materials come in. So I grabbed a tape measure and stuck it down the opening to see how far I could go.

As you can see in the picture, I can only get the tape measure down 12 inches before I hit dirt. Is this an accurate way to measure how deep the post is buried?? Like, could the post itself still go deeper since it is hollow?

The frost line in my area is 30 inches. There's no way this is done correctly, right?

q fence post installation issue
q fence post installation issue
  10 answers
  • Rebecca Stauffer Rebecca Stauffer on Jul 18, 2021

    if your frost line is 30 in they should have dug it 30 inches

  • Redcatcec Redcatcec on Jul 18, 2021

    Here's a rule of thumb guide to help you:

    Here are a four tips to help you find the correct fence post hole depth:

    1. Keep the height of your fence in mind when digging your post holes. As a general rule of thumb, you’ll need to place at least 1/3 the height of the post in the ground. For example, a 6-foot tall fence will need at least 2 feet of post in the ground.
    2. Consider the frost line in your area. The bottom of the post needs to sit below the frost line (consult local codes for exact requirements). The frost line (also called frost depth) varies from region to region. For example, the frost line in Charlotte, North Carolina is 12 inches, while the frost line in Denver, Colorado is 36 inches.
    3. Check local building codes. Some building codes may have specific requirements based on the frost line, soil type and other variables.
    4. Plan to dig your post holes 6 inches deeper to have room for gravel. Holes should also be dug 10-12 inches wide or about 3 times the width of the post.

    You'll have to do a little research for your area to figure out where the frost line is. That will help you in making your decision on whether or not they need to redo it. Being quality contractores, they should have all the facts before they start and finish the project.

    ref: https://www.outdooressentialproducts.com/en/Projects/How-deep-to-dig-fence-post-holes

  • I think the only way to see how deep they went is to dig down on one side of it.

  • Seth Seth on Jul 18, 2021

    How high is your post now? The frost line has little to do with how far down your post is. While the post hole should be below the frost line and filled with a drainable material, the actual post is probably following the 1/3 rule. Find out from the builder what the original height of the post was and if they were cut shorter. The bottom of the post may have been open to begin with, and the opening in your picture is designed to be filled with concrete or dirt. All of the posts might not be done the way the one in the picture is. It's possible they just forgot to finish filling it. Definitely talk to the builder and see what they have to say. You could take a 3 foot length of rebar and bang it down until you hit concrete and see how far down the concrete is.

  • Betsy Betsy on Jul 18, 2021

    Hi Chris: Is there an issue with the post besides your feelings? Are the posts leaning or anything? I'd take pictures of the posts now and wait to see if you have any issues down the line. However, I'd text the company and tell them of your concerns and have them text you back with some solution and when they will come out to inspect this. This way you have a written conversation in case you need to go to court over poor workmanship. In my city, we have to have everything inspected, even how deep the holes are! I wouldn't ask them if anything was cut off of the post as they can say "No", indicating that the post is as deep as they say it is and not just the 12" you say it is. Just because the concrete is deep, doesn't mean that the post was set into the bottom of it. If you have them, or someone else, do the rest of the work, I'd be right there checking the work. And, if you have to have a permit, like we do, the city may have you pull it all out and start over. The company is the one who should have pulled a permit, if one is needed. Don't ever, EVER, pull a permit for a company. Whomever pulls the permit is saying that THEY are doing the work and if something goes wonky, the permit puller is on the hook for it. If the company says they can save you some money if you pull the permit, kick them to the curb, they are not a good company.

    I also found this: "You should always bury one-third of your fence post underground. ... This means that unless you are building a 2-foot fence, which is unlikely in any garden, a 1-foot hole will not be deep enough to support your post. For main and gateposts, you should dig the holes an additional 6 inches deep."

    Hope this helps

    Good luck

  • William William on Jul 18, 2021

    I would assume the post is deep enough. You may be hitting the concrete or the dirt. The hole (slot) you took the measurement is where the bottom fence rail snaps in. The concrete is not only on the surface it's in the post hole holding the post. The manufacturer of the fence allows for proper length of the post for frost lines. The only possibility is instead of digging down to the frost line they cut the post short so as not having to dig as deep as needed. That would be laziness on their part and may void the fence warranty. I would question them on what they did and if it was done properly. Write any notations on the contract and bill of sale.

  • Kathy Gunter Law Kathy Gunter Law on Jul 19, 2021

    You can measure the post and calculate how dee they are buried but they could have cut them. Not sure what the frost line has to do with the depth. It is based on high they are above ground and material. For example, t posts only go a few inches but 6’ above ground wood should be 2-1/2’ buried.

  • Jim Cox Jim Cox on Jul 20, 2021

    Agreed on the rebar trick, and call your insurance company as well. IF there's an issue in the future, you want someone on your side. Here in Missouri we get enough wind to take down a poorly installed fence here and there.

  • Sharon Sharon on Jul 20, 2021

    Having lived in NWT, I believe the post should be below the permafrost level. Where do you live? if there is a town nearby that has a public works dept., I would ask them or an old-timer. We used to do our horse fencing 6' down. https://www.outdooressentialproducts.com/en/Projects/How-deep-to-dig-fence-post-holes

  • Kmdreamer Kmdreamer on Jul 22, 2021

    The post needs to go down about 18 inches then cement footer should be installed and the post set in it