I’m thinking about using doug fir for the rails and posts for my six- foot exterior yard fence-the posts will be bolted in to brackets cemented in to the ground and the pickets will all be redwood. Anybody got an opinion on why or why not I should procede this way?
Thanks,
John from Sacramento, CA
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Replies
How long is the fence? I don't think post brackets can stand that much lateral force if the wind blows on the fence.
The posts are spaced 6' on center and the full length of the fence is approx 24'. Two of the posts will be connected to ledgers boards (which have been installed on the side of my garage) with five foot stringers (this fence encloses the sidewalk next to my garage). Additionally, the final post has been sunk in to the ground inches.
Doug fir is good stuff. I worked at a lumber yard and one of the guys made a jig for building picnic tables using doug fir.
John,
I'm in Woodland/Davis. Doug Fir will rot out in a couple of years. Especially in those locations with wood-to-wood contact, i.e., locations where the wood doesn't get enough air flow to dry out completely. Spend the extra money and get redwood. And get Construction Heart, not Construction Common. Your fence is 24', right? That's 48' in rails @ two rails per section. That's only about $50 extra for redwood around here.
I admire your goal to keep wood out of the ground, where even redwood will rot. Today's redwood is nowhere near the rot-resistance of the old growth. But this plan is simply not a good idea. Even the best Simpson column bases w/ two 5/8" bolts create a hinge point at the bottom of the post. Not a problem with a trellis/pergola with its corners, but fences just don't have enough corners. To counteract the leveraged moment at the top of a fence, posts are therefore sunk into the ground with ballast- typically concrete out here, but other parts of the country use and swear by gravel.
We treat our redwood posts where they will in or near the ground with liquid epoxy. In theory, this seals the wood from moisture, but more importantly from microbes that lead to rot (this theory is hard to test except over 20-25 years). You can get this at a quality paint store or online. Or use Jasco for a couple more years longevity.
I apologize, I just cost you $150 in materials, but you will be rewarded by a much longer lasting fence. Sorry, just a big fan of that "always enough money to do it right the second time" adage.
And lumber yards have better redwood than the box stores out here. And find one that will let you pick it out (e.g. Hibbert Lumber in Davis). With some time, you'll get straighter, cleaner wood with less sap wood (that's the whiter colored redwood that has much less decay resistance).
How much is a redwood 2x4-8? The reason I ask is that we don't get much redwood around here, except speical order stuff, and I'm just wondering how much $$$ it is.
My yard has a Con. Heart 2x4x8' for about $11, 4x4x8' about $23. I can get 'em cheaper, but it means a drive of at least 30 min. roundtrip. And our yard lets us sort and pick.
Thanks for the input. I'm definately going to change a few things and and I'm going for the redwood. One of my posts, which is going to be in a bracket, is part of a trellis that connects to the fence, so I'm going to go ahead and keep it as is-the bracket is one of those Simpson 5/8" hole models, so I'll keep an eye on it if it gets windy. Fortunately, the fence is on the side of the house that is most sheltered from the wind, so even at 50 mph it seems like the calm before the storm there.That side of the house had been all concreted around the existing posts and its been a bear to remove some of them (drilled a few, busted out a few others). In any case, I don't mind spending the extra $150-200 to get it right. I just thought I'd take a stab at using up some of the extra lumber I've got laying around...Thanks,John
I agree with Ryan using the correct material up front is the best way to go in the end you will be much happier.
John, If you are going to place your post in the ground do these things first dig the hole two feet deep minimum and 12" dia. then place 3/4" to 1" sized crushed rock at the bottom about 6" then place you post in the hole and back fill around the post with more rock up about 6" to 8" while you plumb the post. Then place mixed concrete around the post at about another 6" then cover the rest with rock and or soil. Remember to treat the post with a wood preservitive before you place it into the ground. by using the crushed rock around the base it will allow the water to drain away from the post base and keep it off of the wet soil.
This works well in east Davis not to much clay as well as Redondo Beach, Ca. which has sandy lome.
Sorry to say creasote is nolonger avalible here in the peoples republic of Calif.
Edited 1/5/2007 12:56 pm ET by TonyCz
I have always used galvanized metal straps that are about .25" x 1.0" and place them so that one is at the front of the post and one at the rear. It is much stiffer than if you place them on the side of the post. If the post does get damaged you can easily replace it. I have been doing this for about 22 years and have not sen one problem. When I do install the post I raise it up slightly from the concrete in the hole. The straps I use are about 2 feet long. One foot in the concrete and one foot on the post.
The best thing for any wood outside is Jasco's Termin-8. Also, consider using galvanized pipe rather than wood for the posts. Bolt the wood to it with U-brackets. It'll rust out eventually, but not as fast as wood rots or gets eaten by termites.
-- J.S.
Buy pressure treated 4x4 for the posts. Bury them, 16-24"
I have to say I've gone down the some logical path. Installed a 6-2 fence using simpsons column bases and SDS screws. I would have preferred something longer than the 16 or so ", even considered custom angle iron or i-iron, or even steel posts wrapped. Why? b/c of all the fences I've replaced I've _never_ replaced one for a reason other than rotted posts. And since this was @ my house, and I don't want to (re)build the fence... there's some good discussions here about posts/ rot if you poke around some.
The biggest concern was wind forces. I wouldn't do this if it were a tall or heavy fence, or extremely exposed to prevailing winds (mine was between houses). So far it's endured 50+mph winds w/o any affect.
As far as DF, again, the way I see it, you can leave a piece of DF outside for many years with no rot, _unless_ it is in contact with something... sooo, I've considered some kind of non-organic spacer or such that will allow the wood to get wet, and dry just as easily. Haven't actually implemented that thought just yet, however, but it's in the hopper... Cedar is another reasonable option, jic. Redwood is nice, too, but still will rot out eventually, as will using 6x6 posts (same problem, just takes longer). Good luck, I'd be curious to hear what you go with.