fence posts. 2x2 vs 4x4 vs landscape timbers (2024)

For heaven's sake don't use 2x2s. (Treated 2x2s that are for sale are most likely short ones meant for deck railing, um, 'pickets', whatever you'd call the vertical infill). Too twisty and WAY too weak, also you probably can't get 'em in long enough lengths anyhow.

Use p/t 4x4s for all corners, for sure. (Unless you use something stronger, like larger-diameter cedar posts)

For line posts, if strength is not a big issue i.e. there is no exposure to anybody's loose dogs or coyotes AND you do not expect to ever accidentally whomp into the fence with the lawnmower, you can TRY cheaping out by using p/t 2x4s instead of 4x4s. Use them end-on, so that when you are standing outside the fence looking at it, you are seeing the 2" edge not the wider edge. HOWEVER this will give you a weaker and wibblier fence. If you adequately frame between them, top and bottom, with 2x4s (p/t for the one that is virtually on the ground, plain wood for the top 'rail') then the difference is not huge, so if you were planning on doing that ANYhow, maybe 2x4 line posts is a reasonable option. But if you were planning on NOT having any (that is to say, two runs of) horizontal lumber between posts, then I for sure would stick with p/t 4x4s for line posts too. They are not THAT expensive.

In case you were going to ask about t-posts, I would put them in the same category as 2x4s only harder to attach horizontal framing to. I suppose if you were going to skip any horizontal lumber in the fence and were dead set on not using 4x4s an argument could be made that WELL DRIVEN HEAVY DUTY t-posts are slightly better than p/t 2x4s in most soils... but then they are also more expensive unless you can get some old ones for free or cheap

Good luck, have fun,

Pat

You say you are looking for our ideas. I'll look at it more as you asking what mistakes have we made and address it more from that aspect.

You are building a chicken moat. That means two fences, one big strong one outside to keep critters out and one inside that just has to keep the chickens in. Predators should not be a threat to the inside fence. I'd hope you have a coop to lock them in at night since that type of run would be real hard to keep climbing or digging predators out without spending a lot of money and doing a lot of work. The gates alone would be a real challenge.

I would not use 2x2's as posts. Different reasons, but mainly any knot in the wood is a real weak spot since they are so small. I don't get the 2x2's anymore anyway since I found that one 2x4 is usually cheaper than a 2x2. I have a good table saw so I can rip the 2x4 and have two 2x2's that are a lot less warped and a lot less expensive than a purchased 2x2. By choosing my 2x4's carefully, I can get ones that don't have the big knots that cause the worst problems, but even a small knot can severly weaken one. I use the split 2x4's to put small deer fences around my individual trees. I would not use them in a regular fence as posts.

You don't say what kind of fencing material you are using, wood or wire. If money is a concern, I'd think wire, especially for the inside fence. Any corner post or any post you are going to stretch wire has to be substantial or you willk break it off. Bending the wire to go around corners really puts a lot of stress on those posts. Use something heavy for the corner posts and brace them before you stretch the wire. Gate posts need to be strong and well braced too. If all you are doing is attaching the wire to the posts, they do not have to be that substantial. I don't know how long a treated 2x4 or a treated 2x4 ripped into a 2x2 (I know. Actually a 1-1/2" x 1-3/4") will last in your soil type and climate. Obviously not as long as a 4x4, landscape timber, or a 3" diameter post that I can buy at Lowe's. For the inside fence, I'd give serious consideration to using treated 2x4's for the intermediate posts, picking them to avoid knots. Turn them so you are nailing the staples into the narrow side of the 2x4. That way the stronger section of the 2x4 will be lined up to take what should be the heavier forces hitting it. I personally would not use the ripped 2x4's as fence posts. I just think they would be too high a risk to break even if you watched the knots.

The outside fence is different. It needs to be stronger. It is not just for predators and kids running into it. You'll probably hit it with your lawn mower, but it also has to stand up to wind load. You'd be surprised how much force a strong wind can put on even wire fences. Vines may grow up it or ice may form on it. That presents a solid surface for the wind to blow against. Odds are your outside fence will protect your inside fence from wind. That's why I am not so worried about it. Depending on conditions in your specific circ*mstances, you might consider using treated 2x4's as intermediate posts on your outside fence, or maybe using 2x4 as every other internmediate post, but I'd tend to something more substantial.

Just a few more ideas. Hope you can pick something out of this that helps.

I am in the middle of building a new chicken house and a new run. The chicken house is really the safe strong house for them, the run is more a place to gather than at the end of the day prior to locking them up and a place to keep them when we have a reason to not allow them in the rest of the lower garden area.

The fence around the lower garden is all chainlink or wood (on the property lines) We fenced our veggie garden in the center of the lower garden area (30x70). We had a bunch of old top rail chain link posts on the property, I cut them in half and used a pounder to sink them in the ground (much easier than digging post holes!) And since the only thing we are keeping out is hens, they do not have to be super sturdy. We found gates free on craigslist through an ad and used heavier posts for the gates. We used some free plastic fencing last year as a test run on the size of the garden. This year we hope to re-fence with more 4' chainlink or break down and purchase garden wire.

The chickens have a 20-30+ foot wide "moat" all around the garden. We have a lot of trees in the moat/orchard section. The chickens (and a roo) have plenty of places to dig and kick. They do make it over the fence or under it in to the garden, but we have also stopped worrying about the plastic fencing condition because we plan on replacing it shortly.

We have EE's and SLW's, maybe they are too heavy, but we have not had a problem with a hawk. The hawks roost/nest at the back side of a large property near us. The Rooster is very good at letting the ladies know if there is any other bird flying over head. Cant recall loosing a chicken to a hawk in the past 30+ years. We have all fruit trees in the orchard, those attract crows so that might be part of the reason the hawks leave our lot alone.

We don't do lawn/grass in that lower section, the brown EE's might blend better with the leaves and dirt too.

If your space is similar, you might want to rethink even using wood for the garden area. Craigslist is a great place to get or give away free materials.

ok, I'm convinced. 2x2 is not strong enough. today I found a source for cheap 2x4's. How about screwing 2 2x4's together. i"m sure that would be strong enough but I'm wondering if water would get between them and rot way faster. and yes, they are treated.
by "cheap" I mean free

Well, I wouldn't do it. At least use treated 4x4s for the corners.

If you are dead set on using p/t 2x4s as line posts, you will either need to a) frame the fence out top and bottom as described in earlier posts (only the bottom 'rail' need be p/t) and accept a somewhat weaker fence especially if it is long; or b) don't sister the 2x4s together to make a 4x4, sister them together to make essentially a wooden T-post. So the narrow side of one is along the mddle of the wide side of the other. Affix well and often, all along their length. This is not as long-lived or strong as a 4x4 but it offers reasonable protection against warping and twisting.

Remember that you need to use appropriately-coated or stainless-steel or VERY heavily galvanized hardware for pressure treated lumber, else the acids in the lumber 'eat' the metal and it weakens and comes apart very prematurely. Coated deck screws are fine for places that do not require any particular shear strength but you will need to use something else where shear forces will exist.

Good luck, have fun,

Pat