# Building a fence question



## 12point

Im gonna be building a fence in the near future i just wanted to ask a few questions about some things i wasnt 100% on.

Im using 4×4x8 post,,,how deep should i have my holes? 2 ft?

Should i use concrete on every post? They will be 8ft apart

How much space betweeen my dog eared pickets should i allow?

How far off the ground should the bottom my pickets be?

Thanks


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## lew

Before you go too far, you may want to check local ordinances. Many locations have limits on fences.

Years ago, I built a privacy fence. Used treated 4×4's, 2' deep in concrete. Later, I read that concrete was not recommended but the posts still stand!


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## 12point

thanks for the info, lew


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## ChrisForthofer

Check with your local ordinances as well as your HOA if you have one as Lew recomends. They will save you the grief of potentially cutting a foot off the top of your new 6' fence to make it a 5' one. 2 schools of thought on the concrete, one camp says use it with treated posts and you will be fine. If the posts are treated properly you have about 20-25 years before the moisture the concrete holds against it will start to rot it. Others say use gravel and tamp it to "lock" the post in the hole. Better drainage for the wood when water is in there but the holes can and will fill up with water if your soil doesnt drain well. Also gravel has its problems as you will never get it to firm up if the soil you are putting your posts in is soft to begin with.

I feel the concrete option is better myself and if it were me I'd use it on every post, remember each 8 foot span is a sail in the wind, the fence has to support that load in addition to its own weight. Distance between pickets is a personal choice, minimum of 1/8" would a good rule of thumb. This is just for airflow/drainage and to keep debris from getting stuck between the boards (pine needles etc.) As to how far off the ground, an inch should be fine, just so they are not touching soil is what you are looking for. Good luck.

Chris.


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## 12point

Thanks alot Chris. Answered all my questions!

Just for clarification,,, i live out in the middle of nowhere in the country. There is no HOA.


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## KnotWright

As a person who has built WAY too much fencing in my life, miles and miles…here's just a few more pointers.

When you pour the concrete around the posts, pour it high and try to slope it away from the posts. A lot of people like pouring it low and putting dirt over the top of it. This forms a bowl that invites water to collect against the post.

On your rails, try installing one 16' on bottom followed by another 16'. Then on top start with an 8' followed by a 16'. This keep the joints alternating making the fence a little stronger in the long runs.

Depending on if you have pets that you are trying to keep in, the higher off the ground you can keep the pickets the better. It a lot easier to cut the grass with 3" of space under the fence.

As for your pickets, if you are going for privacy you tend to want them as tight together as possible. If you are buying pickets that are "wet" when you install them, you don't have to worry about them swelling after installation and you can just "but" the pickets together without spacing them. If the pickets are really dry while you are installing them, you might consider spacing them slightly to prevent them from swelling when they do get wet, and working themselves loose later on.


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## JCantin

Another tip is to strip out a generous patch of grass along the fence's path before installing. Lay in some crushed stone after your posts are in but before you install the panels. This will make it easier to mow and protect the bottoms of your pickets from moisture.


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## mnguy

A rule of thumb I have read and used for post depth is 1/3 of the total post height. For my fence posts, I've taken a hybrid approach with setting them; pour some pea gravel in the bottom of the hole, set and plumb the post, and pour in one bag of quick-set post concrete, pour in water. 30 minutes later, you can remove the bracing and back fill the rest of the hole. Where I have run into a large tree root, I have set the post shallower and filled the hole with concrete and then sloped the top as suggested by KnotRight.

IMO, the best approach would be to set the post deeply and backfill with tamped soil, but this is a lot of work and time, and I've never done it that way due to laziness and impatience 

I have also taken the time to treat the buried portion of cedar posts with wood preservative before setting them, especially the open grain on the bottom. A little insurance against rot.


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## Gregn

I set my post 24"- 30" deep 8' apart. I set my post with pea gravel, it allows for moisture to drain away. Concrete draws moisture and will rot out the post. I space my pickets the thickness of a picket apart to allow for expansion and contraction and allows for wind to pass through. I set my pickets 2"- 3" off the ground to allow for weed eating and to keep the pickets from drawing moisture.


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## gpastor

You could try this, I am going to try it this spring.
Fence Pole Installation Without Cement pt 2


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## 12point

Let me ask yal this….about how wide does my hole need to be for my posts?


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## C_PLUS_Woodworker

Assuming you are using a post-hole digger and few rocks….....then your hole the size of your post hole digger will be just right.

Shovels make a hole a little too big for your sized posts, as do rocks, but neither can be avoided totally.

BTW, the Big Orange Box has post holes on sale this weekend…..........10 holes for 50 bucks. You might want to consider that as an option.


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## davidroberts

Im using 4×4×8 post,,,how deep should i have my holes? 2 ft? - 2 feet minimum

Should i use concrete on every post? They will be 8ft apart - yes, concrete is good. use the type of concrete that you don't add water. the concrete adsorbs moisture from the surrounding soil. one bag per hole. cool stuff.

How much space betweeen my dog eared pickets should i allow? - if using pressure treated then none. the pickets are wet and will shrink to about 1/4 to 3/8 gap in the pickets. otherwise, 1/8 inch on non treated.

How far off the ground should the bottom my pickets be? - Personally I use a sacrificial 1×6 along the bottom and sit your pickets on top. When it finally rots out, just replace it.

Rent a gas powered post hole digger with an 8 inch diameter auger for about $50 and spare yourself a lot of pain.


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## Manitario

personally not a fan of concrete and fence posts; eventually you'll replace the fence and it will be a PITA to deal with; I've found 3ft holes with a 4×4 post, tamped with gravel is solid.


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## chris85

@Manitario

I am also getting ready to set up a new wood fence. I would like to use the tamped gravel for the posts, but I have some questions.

1. How much gravel will I need?

2. Is gravel more cost effective then concrete?

3. What kind of gravel?

unrealted, but should i be using nails or screw for the pickets? I have heard mixed reviews it seems.


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## Clarence

If your posts are CCA SYP, you should buy them now and lay them out in your yard for as long as possible so you can get an idea of which ones are going to warp and bow.


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## DMIHOMECENTER

You got a bunch of great answers on here.

Ditto Knotwright on the staggering of your horizontal rails.

If you have more than 10 posts to set, I highly recommend renting a one or two man gas auger for 1/2 day. I had 50 to set on one job and it took two guys about an hour. Make sure to auger a little then lift then auger some more. Especially if you have high clay content, it is NOT FUNNY to auger down 30" and catch hell getting it back out.

On the depth into the ground, if using concrete 24" - 30" is fine for 8' posts. You don't have to add water either unless you live in the desert. The concrete will pick up the moisture in just a bit.

If not using concrete, go with 30" or so and just throw a little gravel in the bottom, tamp it hard with the post itself, then backfill with the native soil and tamp tight (after you have installed cross-members, because you want to be able to have some movement to get it level, plumb and spaced correctly).

On spacing, we let them just touch … and check plumb every board or two and if needed leave a small gap to maintain plumb… all to a string line above that may have to be adjusted if a grade change occurs.

Good luck on your project.


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## 12point

Thanks for allt he help guys!


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## 12point

Is it just preference or is it totally neccesary to have a thin layer of gravel on the bottom of the hole if you are using concrete? I was planning on going straight concrete.

IVe read where it helps the water drain. We dont get a whole lot of rain where im at. Going months at a time without a drop is not out of the norm.


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## EEngineer

Well, as an old farm boy, I set a lot of fence posts. The big thing is to get the bottom of the fence posts below the frost line. If you don't the freezing and thawing will gradually work the post out of the ground. Here in Ohio, the frost line is about 28" deep (hmmm, did a quick Google, can't find confirmation of that - it is what my grandpa always said). I set fence posts about 30-32" deep. I always "bell" the holes - wider at the bottom of the hole. This also helps keep the post from rising with freezing and thawing.

I always put 1-2" of gravel at the bottom of the hole. Again according to my grandpa, it is to let water drain out of the post. If you don't, the water will pool at the bottom of the post and rot it from the bottom up.


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## Jack_T

I agree with EEngineer. You definitely need to set the post deeper than the frost line. I also agree that you should put gravel in the bottom. Rest your post on the gravel, plumb the post and add the concrete. Don't forget to string a line so that all you posts line up.


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## Grumpypantsmcgee

Well Brant if you are anything like me you haven't finished the project. Lets say I am savoring the moments I am not building it.

At this point I am certain that if one builds a fence with any kind of zeal it will out live them.

So live life to its fullest and try not to worry too much about the details.

Concrete, slopes, shovel wide, 1/3 deep, as long as you like.


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## FenceWorkshop

Im using 4×4×8 post,,,how deep should i have my holes? 2 ft? *Yes*

Should i use concrete on every post? They will be 8ft apart *Yes*

How much space betweeen my dog eared pickets should i allow? Depends on the wood privacy fence style

How far off the ground should the bottom my pickets be? It's give and take. The closer, the more secure and the more likely the pickets are to rot from the moisture. When it's up to me, I typically do about 3 inches from soil. Good luck.


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## 987Ron

A bit off topic:
Many years ago (65 or so) as a kid I cut a few lawns for some spending money. This was before powered trimers. So trimming along the fence or walk way with hand trimmers always was tedious, and blister forming. I remember one man who made each panel held to the posts with 3 bolts on each side. He would remove the top and bottom bolts on each side, tilt the panel and run the lawn mower where the fence had been. Then lower it back and reinstall the bolts. Only trimming was around the posts. At 15 I thought him brilliant. Still think of it occassionaly maybe let the fallen leaves blow away.


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## therealSteveN

I have replaced a few fences due to rot, and it was always encased in concrete which retains, and seems to draw in water. The better method is packing the post bottom in gravel that can drain well, and the top in good soil that will grow grass around the post, mixed with some finer aggregate to facilitate drainage, and keep the soil from clumping.

Always check the local laws.rules/ordinances, not to is usually expensive.

Height above ground, and local weather will dictate hole depth. Code may be ok for this, but you want to reference what is common in your area. Freeze Thaw are real, and will control the depth needed to make sure your shallow posts don't heave out after freezing. It makes sense that you need more anchor if you are waving a larger, taller, than normal wind screen at the wind. More anchor only comes with a deeper hole.


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