embarassing fence question

[Gregg Feldstone]

Well, I paid an electrician to build a wooden privacy fence for me. He said he'd done it lots of times and knows what he's doing. Well......
He went ahead and "notched" (dadoed) out all of the 4x4 posts where each of the three rails are attached. The 2x4 rails are oriented vertically, so that the 3 1/2" dimension is up and down. The dados are 1 1/4" deep.
This only leaves 2 1/4" of wood at three points on each post. Two corner posts are even worse, since they are dadoed on two faces. The dados are all facing the outside of the fence, which is most likely to have the strongest wind going at it. Do you guys think this makes the fence a lot weaker? Any suggestions how to make it stronger other than starting over?

[Ross Canant]

2 1/4" is thicker than a 2x4 (1.5"). Would you expect a 2x4 to break in that situation? I think you are likely ok. Now if a hurricane shows up, all bets are off. I just got in from Tokyo. What's your excuse for a 4:00am post?

[Gregg Feldstone]

killing a little time on break at work. On the fence; You would not build a fnece with posts made of 2x4's.

[Colin Wollerman]

Ross, I am not a professional fence builder (I am an electrician actually:D)but the 2X inserted into the dado will return a good portion of the post strength. Someone else here might know if it is better to have a really tight fit in the dado or a little loose to alllow for expantion of the post and 2x.
Personally I would be more concerned about moisture getting in all the dado seams and rotting the post. I would use zinzer primer in the dados before installing the rails.
Sounds like a nice fence actually.
C

[Gregg Feldstone]

The posts and rails are all treated lumber. The dados are VERY loose. Still plenty of room to add some glue if I wanted. They are just nailed together with 3 1/4" framing nails. I would be much happier if the dados faced inward, thereby allowing the posts to collapse against the 2x's instead of away from them. The rails had to be on the inside per city code, allowing the nice smooth pickets on the outside.

[Doug Carpenter]

You could add a 2 by 4 onto the post. Basically laying it flat over the post and the crossing members that are dadoed in. That would trap them in and add to the strength of the posts.

The real concern is the post warping like a son of gun. It is more likley to do so since they are notched. Treaded wood has a tendency to go wild anyway but the 2 by 4 's would help tremendously.

My 2 cents

The construction industry is currently suffering something like 37% unemployment. It was a nice gesture to hire the guy anyway. I would say that is an fixable mistake. No biggie.:)

[Terry Welty]

I think you should be fine... I do like the 2 x 4 over the dado side if you're really concerned... I would have used screws vs nails however.

[Will Overton]

I think you should be fine... I do like the 2 x 4 over the dado side if you're really concerned... I would have used screws vs nails however.

I agree, and if you chamfer the 2x4's so the edges come closer to the thickness of the fencing material, it will look more like a design element than a structural member.

[David Thompson 27577]

[QUOTE=Gregg Feldstone;1434245]....................
He went ahead and "notched" (dadoed) out all of the 4x4 posts where each of the three rails are attached. The 2x4 rails are oriented vertically, so that the 3 1/2" dimension is up and down. The dados are 1 1/4" deep.
This only leaves 2 1/4" of wood at three points on each post.................... /QUOTE]

Deck railings are done this way all the time -- and they have to meet a building code standard of 200 pounds of sideways force.

You'll have no problem.

[Fred Belknap]

If he nailed a vertical 2x4 at the post it would make it stronger but I don't see a problem with strength.

[Gregg Feldstone]

Thanks for your responses. I am considering Dough's suggestion of laying a 2x4 over the post. It would be much easier to do so on the non-dadoed side, making it look like 5" thick posts with dados on one side. To add the 2x4's to the dado-ed side would entail making 1/4" dados in the 2x4's themselves, otherwise they won't lay flat against the posts. The rails lay 1/4" proud of the posts to keep a straight line for the pickets. Also, the 2x4's would not fill the space of the removed 5 1/2" wide picket or portion thereof. I would have to use 2x6's or maybe 1x6's. I would than have to possibly rip them down a little. Also, many posts are covered with evenly split halves of pickets, and other combinations. Do you guys think a solidly screwed and glued addition to the un-dado-ed side would do the trick?
I have also had the suggestion to add an additional post 3' to each side of the two corner posts (which have two faces dado-ed. Is that overkill?

[Aaron Wingert]

Strength won't be an issue. But I agree that the fence posts will likely bend/warp. Deck posts are done this way fairly frequently, but they benefit from the structure of the deck framing and the railing system to retain some lateral stability in the post when it would rather warp. The fence has no perpendicular members to add that stability like the deck does, and is generally free to move.

I think I'd go with adding at least a 1x over each dado...The longer the better. As suggested, it wouldn't look that odd if done neatly.

I guess hiring an electrician to build a fence is better than hiring a fence builder to wire your house. :D

[Kent A Bathurst]

Should be plenty strong enough. Screws, not nails, into pre-drilled holes - definitely. The pre-drilling isn't exactly "necessary" as a pilot hole - it helps a lot to minimize splits in the PT wood as it dries - especially at the ends of the piece - I always pre-drill anything I'm doing with PT for that reason.

Glue or Liq Nails or somehting like that - complete waste of time with the PT (unless you come back in a couple years to do it).

BTW - if you measure some of the 2x4's, you'll find that the 3-1/2" dimension ranges up to over 3-5/8" (assuming recently installed). Results of the PT process. Will shrink as it dries - over the next year or so. So - loose fit today = looser fit tomorrow, but that wouldn't concern me - that's just the way the stuff is.

On David's note about notched deck posts - You should be very reluctant to install notched posts with the post mounted on the outside of the deck's support structure (ie - so the notch is to the inside) - that square cut is a weak point in the structure.. If you mount the post to the inside of the structural support, with the notch facing out, no problem - a hit is trying to collapse the cut, not snap it off. This is more troublesome to do, because the decking has to be notched around the post. In fact, I would not use notched posts at all. If for some reason, the fence were to fail, then some daffodils get crushed. If the deck post/rail fails, the consequences are potentially much, much greater.

I offer these comments only as a caution - in a previous life I had exposure to extensive testing at professional test lab(s) of exactly this type of post in exactly these configurations, and I know what the results were. I personally would never consider installing them "notch in", nor consider letting them be installed that way by a contractor. Just my $0.02.

[Gary Click]

I build my fence in this manner with a 3/4" dado on each side 25 years ago out of PT material and it is still fine although heavily weathered. The fence, 425', has been through high winds and a Cat 1 hurricane with winds in the 70mph range and hasn't snapped off, blown over or broken posts. A dozen or so posts have been replaced due to poor PT. Some 2x4's and 1x6" have been replaced for various reasons - falling limbs, son on lawn tractor, etc.

The fence is 4"x4" posts set 30" in the ground, eight feet on center. Three 2x4"'s two horizontal one vertical and dog eared 1x6"x6' boards. Corners were done in the same fashion as you describe but set in concrete. Double gates are biased with a 3' wide and 5' wide gate with center pin on the 5' gate.