Ground sleeve for 4X4 wood post

[James Rieman]

I know this is off topic a bit, but I hope some of you with bluebird, wood duck or other types of nest boxes might be able to guide me on my next project. I recently purchased a nest box for Black-bellied Whistling Ducks (there are tons of these on the bayou I live on and they are constantly scanning the trees on my property for nesting cavities). It can also double as a Wood Duck nest box. I would like to mount it on an eight or ten foot 4x4 wood pressure treated post with a predator guard. In case my original site does not work I would like the ability to move it so I am looking for ideas for a ground sleeve for this post. Any suggestions? Another question - since it won't be as high as a martin house and will have less of a profile to catch the wind do you think I can get away with less than a two foot hole? Any other suggestions from those with experience would be greatly appreciated.

Thanks

Jim

[CraigMo.]

I know they make stakes for mailboxes that you insert the 4x4 in but am not sure if that would be strong enough for a post that tall. Just a thought
Craig

[lynnh]

Jim I have been using one of those pvc sleeves with 4 by 4 by 12 ft tall with a t-10 on it for 3 yrs now, its 3 ft in the ground though.Its holding up just fine....Lynn

[James Rieman]

Lynn, are you using a square PVC sleeve? I would think a round would be too loose and need to be 5.7 inch diameter or so. What is your source?

[lynnh]

Home depot or Lowes I think and yes its a square sleeve....Lynn.

[DAVE]

Lowes and Home Depot sell vinyl fencing that have sleeves for 4x4 post that slide over it. I'm not sure how much side pressure they will stand. Maybe you should pour concrete up to the top. This will make it stronger to with stand the side pressure. Good luck!
Dave

[BirdBrain]

Earlier this spring I had the same dilemma with a square steel pole I wanted to set in concrete but be able to move it. I bought a roll of flashing at Home Depot and it worked perfectly.

Flashing is aluminum sheeting for joining HVAC ductwork that's something like 3-4x as thick as aluminum foil. A little stiffer than soda can aluminum but it takes a set better.

The roll was 10" wide so it worked perfectly for me. I cut the length I needed, pre-bent it into the needed shape, wrapped it around the pole (with 2" overlap), fastened it with zip-ties, stood it in the ground and poured the concrete around it. It took just a little wiggling to get it out of the sleeve once the concrete had set.

You'll need to cut two lengths of flashing and join them along the long edge with a single edge hem:



Make your hems, say, 1" wide and the resulting strip of flashing will be ~18" wide. The perimeter of your post is 16", so that gives you complete coverage with a 2" overlap. (or is it actually like 3.5"x3.5"?)

My hunch is it will be easier to work with if you put the hem in the center of a face instead of at a corner. That also will position your overlap in the middle of the opposite face.

Or you could center one strip on a corner, then bend it. The center the other strip on the opposite corner and do likewise. The two strips would overlap by ~2, across the adjoining corners. Something like this (end-on view):



The spacing appears exaggerated because my drafting tool is a bit crude. I didn't get wrapped around the axle about making the flashing fit tightly, and the concrete will push it in a bit. The pole doesn't wobble at all in the socket, but it helps that I've got it buried two feet in the ground.

I left my flashing sleeve about 1" longer than the hole was deep, which probably was a mistake. If I had to do it over, I'd make it 1" shorter than the hole, then "groom" the concrete so it sloped down to the hole, making a sort of beveled opening for guiding the post into the hole. Then again, I'm working with an 18-foot long pole, which is a little unwieldy to stand upright and try to feed into a tight fitting hole.

The beveled hole might gather rainwater but it's a certainty I'll eventually bungle sticking the pole back in the hole and trash what's sticking up anyway.

[db]

You might try this, Cut four pieces of cardboard the width of the 4x4 and about 2 feet long. Duct tape to the bottom of the 4x4. Dig your hole and put the cardboard taped end of the 4x4 in the hole and pour sackcrete in the hole use a level to plum the 4x4. When the sackcrete is dry, you should be able to remove the 4x4 as the cardboard should allow a little "give" on each side.

(Disclaimer) I've never tried this.

[James Rieman]

Wow! Great ideas, thanks everyone, I have lots of options. I like the idea of setting the sleeve a bit below the cement level and grooming the concrete to slope a bit down the hole. I am heading to the hardware store today to see about getting aluminum flashing or a PVC sleeve. Thanks so much for the help!