Picket fence -- span?

Re: Picket fence -- span?

Jim Shaver - Oakville, Ontario

>Hi Jeremy,

I can't really help you, but I was just thinking about you the other day and wondering where you were and how things were going, All our best to you and Family!

:-)

Take care,

Jim

Re: Picket fence -- span?

Jeremy Osner

>Thanks Jim -- we're doing fine. You can take a look at our family pictures here: http://www.flickr.com/photos/readin -- recent stuff includes the Fourth of July parade, and Sylvia's violin recital in her class at school. Hope you guys are doing well. Dana must be getting pretty big!

Re: Picket fence -- span?

Bill Houghton, Sebastopol, CA

>White oak is considered durable outdoors (unlike red oak), so that should be OK. I don't know if you plan any kind of weather protection; I imagine it would weather gray without any protection, but I don't know if it goes splintery.

Out here, sellers often are kind of vague about what kind of oak they're selling, so make sure your additional wood is in fact white oak. My understanding is that white oak's cellular structure is more water-resistant than other oaks, leading to better weather resistance. Someone more knowledgeable is welcome to demonstrate how ignorant I am.

Even with oak (oak for a fence! Wow), ten feet seems like a long span between posts. Most fences I've seen don't exceed eight feet. You could split the length, and have additional posts at five feet, or, maybe better, look for a way to add some fanciness to the fence with posts close to the walkway - get a formal entrance kind of effect with extra posts.

Your little girl is sure growing up

Bill Houghton, Sebastopol, CA

>Seems like the last picture I saw was of a toddler.

She looks very confident in the recital pictures.

Re: Picket fence -- span?

Warren in Lancaster, PA

>Generally posts are spaced at half the length of the boards so that each board is fastened to three posts. The joints are staggered in a long fence. A board fastened to only two posts is much more free to warp and sag than one fastened to three. An 8 foot board attached to two posts will sag more than a 16 foot board attached to three posts (even though the spans are the same) because the ends of the 8 footer are more free to twist. I agree with Bill that you will really want 3 posts.

If you have a top and a bottom rail I would space them so they are centered at 1/4 from the bottom and 1/4 from the top. If they are too far apart, it will look like there should be another rail in between.

I'm with the others here...

Scott Burr in Ben Lomond, CA

>10' is too long of a span. I'd go with 3 posts. The depth of the posts is important also. Where I live we have snady soil. Posts for short fences are 3' deep. Taller frnces 6 footers get 4 to 4-1/2' deep holes. The ground here doesn't freeze, you may have to take that into account also.

White oak seems too nice to make a fence out of to me. Expecally if it's going to get painted but thats MHO. In my neck of the woods redwood or ceader would be used.

Good to see you poking around here again Jeremy!

Thanks all

Jeremy Osner

>Well I'm not sure. I've used cedar for fences before, and it is easy to work with. I just have this rough cut white oak around that I've been meaning to use for some time, and thought I would avoid some expense... OTOH buying white oak to make up the difference in wood I need would probably be as or more expensive as buying cedar for the whole thing. Maybe what I'll do, is use the oak for the posts and rails, and buy cedar for the pickets. That will make this project go much faster anyway, which will make Ellen happy. Thanks Scott for the word about depth of the posts. I did not know that and probably would have not buried them deep enough.

Warren, I don't think I quite got your meaning about the rails -- you mean they should only be 1/4" from the top and bottom? That seems too little. Or did you mean 1/4 of the height of the fence? -- that's probably it.

Re: Thanks all

Marv

>Hi Jeremy,

Here's a thought....so you can have a ten foot span between the two end posts and also support the rails, you could use a stubby post in the ground, in the center under the bottom rail. The pickets will hold up the top rail. I've even used piller blocks to accomplish the same thing. The piller blocks end up about half buried and if you need more of a foot print you can set it in some concrete. For the end posts, a two foot deep hole is plenty deep enough for such a short fence. I never go any deeper than that for a six foot fence, especially if you use the fast setting concrete that's designed for fence posts.

Have fun,

Marv

Coupla nits

Wiley Horne--So. Calif.

>Jeremy,

I agree with the two foot post depth, and four foot spans.

Few other comments, all of the DAMHIKT variety, and I apologize if you've thought of all this already....

Our climate is much different from yours, but I encourage you to ask around about post-setting practice in your area. I've had two picket fences, and other post setting exercises, and what has worked best on the posts is not concrete, but rather wrap the post bottoms in a tar wrap (or just paint the bottoms with tar/asphalt from the Borg), and set them in pea gravel which you can compact with a handy blunt instrument, after making a final check for plumb. The idea being to drain away moisture. If concrete is best for your area, mound it up just a bit so that you have positive drainage away from the base of the post (and I think I would still tar-wrap the bottoms). Any standing water at the base of the post will get between the post and the concrete.

The four foot spans should prevent sag. To keep the posts and pickets aligned, get your ends set first, on both sides of the entry way, and run a mason's line for the post tops, and a second mason's line for the picket tops. Keep tension on these lines (with a dangling block if necessary).

DAMHIKT.

Wiley

Re: Thanks all

Marv

>Jeremy,

When I use the fence post concrete I put a rock or a chunk of brick or something under the bottom of the post to keep it up off the ground so the concrete will work it's way around it down there. As Wiley said, mound the concrete up around ground level so the water will run off. The concrete will tend to shrink around the post but if a crack shows up later, just caulk it or use some other waterproof sealer. The post concrete isn't the same as your regular Redi-Mix like you would use for a sidewalk. This stuff sets up fast and you don't use much water, just enough to make it pack good. It's good stuff. Suran Wrap works good to wrap the bottom end of the post if you want a little insurance against moisture. Suran Wrap is good for at least ten thousand years. I hate the stuff but I'd use it on a fence post.

Marv

Disagree

Bill Houghton, Sebastopol, CA

>What you don't want is a concrete bowl with a post set in it. The bottom few inches of the hole should be gravel, with a few inches of gravel tamped down around the bottom of the post - then concrete. The wood and the concrete will have differential rates of expansion, so water WILL get down between the post and the concrete, and you want it to be able to drain away.

Confession: I hardly ever do that, even though I know I should, but I do tamp some dirt down there around the base of the post before pouring concrete. Our soil, like Scott's, is fairly sandy, so it drains quickly, though not as quickly as gravel.

It all depends on how long you'll live there

Pam Niedermayer - Austin, TX

>If forever, say 20 years or more, I'd over engineer the posts, not a one would be buried or set in concrete. Instead, I'd build concrete posts that are taller than the ground by a few inches and are domed on their tops and have mounting bolts inserted while the concrete is wet. Then I'd sculpt the bottoms of the wooden posts (my choice would be cedar or redwood) to match the domes and drill a place for the bolts and a perpendicular hole for securing the mount.

Then along the completed fence I'd load gravel/rocks up to the top of the dome bottom of the posts.

Pam

Re: Picket fence -- span?

Michael Recchione

>Hi Jeremy,

Unpainted fences around here are made of cedar, usually. Painting cedar is kind of a waste - it weathers really nicely. Painted fences are usually made of whatever. It doesn't matter as long as you keep it painted. White oak is really overkill, given what they charge for it around here. (Better to put the money you save towards a new bow or something :-) ). The posts are usually pressure treated 4x4s, and usually have concrete footings. If it's a short fence, you might be able to get away without the footings. But if it's out front, where people are walking by and maybe leaning on it, etc., you're probably better off with the concrete.

Re: Disagree

Marv

>If you happen to have soil that drains well, then I suppose having gravel around the bottom would be ok. Not all soil drains, like clay for example. Lots of varibles and lots of options. I'm for sealing the wood so it is exposed to a minimum of moisture entrapment.

Marv

Re: It all depends on how long you'll live there

Marv

>Hi Pam,

Years ago I got the bright idea to do something similar to what you are suggesting. I made a wood mold and cast some concrete fence posts with cut-outs for the rails and a means of attaching the rails to the concrete. The idea was to have a fence post that would never rot and just stick it in a hole in the ground and be done with it. The posts were 8 ft. long and were intended for a 6 ft. fence with 2 ft. in the ground. Well...as it turned out, the posts were so darned heavy I needed a forklift to move them around. After casting about four of them I gave up on the idea as a commercial adventure.

Marv

Re: It all depends on how long you'll live there

Glenn Madsen near San Francisco

>Well, there's another part of the question.

We have expansive clay soil. It won't stay put, and neither will most of what we put down into it. That just has to be figured into the mix. Redwood, pressure treated or cedar fence posts will most likely lean before rotting out, in most of this community at least.

Over engineering the post fixtures just makes it harder to deal with in ten to fifteen years. But that's just here. Gotta be different in Texas.

Re: It all depends on how long you'll live there

Marv

>Hi Glenn,

I live north of you in Lake County. I used to live in Milpitas where the soil was old bay bottom, very dark in color. It's the kind of soil that moves also. In the dry season it shrinks and cracks and in the wet season it expands and the cracks go away. We called it "Adobe" mud. Every house has a six foot fence around it. Fences everywhere, mostly redwood. Somehow they seemed to stay put with posts that were about 2 feet in the ground. Thinking about it now, it seems a horrible waste of redwood that is like buying gold now days. Last time I bought a redwood 2 x 6 I had to take out a loan and make monthly payments on it. You can easily spot the rich people around here. They are the ones with a redwood deck or a redwood board strapped to the back of their pickup driving down the highway. It's probably cheaper to build a fence using oak. The last time I considered building a fence on my property, I ended up planting a row of Oleanders instead.

Marv

Re: It all depends on how long you'll live there

Pam Niedermayer - Austin, TX

>Yeah, I've never noticed any tilting fences in Marin or SF. Here we also have clay on top of caliche, sort of river bottom on top of prairie. My back yard is fenced with chain link with concrete anchors, no movement after at least fifteen years (as in I wasn't here when it was fenced, the house is 53 years old).

However, I'll bow to your clay, Glenn; although I doubt this is a problem in NJ.

Pam