pergola building question - foundation

[jd]

hi folks, I'm getting ready to build a pergola/arbor to support my grape vines, and I've run into a snag.... around here, if a "structure" has a foundation (including sonnet tubes), it is considered permanent, and therefore taxable (add even more onto the already astronaomical property taxes)..... I'm planning to build a timberframe style pergola with 6 posts (2 rows of three posts each). The three posts are 6'9" apart, and the 2 rows are 8' apart. The pergola will be 8'6" at the highest point.

My question is: is there any way to build this without putting a "permanent" foundation down? I'd like to avoid tying the posts together at ground level, as I'm hoping to set it up so that people cane walk in and out of it easily (without tripping on a sill).....

Acording to the local building contractor "stakes" are not considered permanent, but I'm not sure a stake wouls provide suffucient strength. I'm not worried about settling (up and down movement), but more racking - the structure will be very rigid at the top - there will be braces from the 6 legs to the top sill, but unless the legs are securely anchored to (or sunken into) the ground, I'm worried about them shifting laterally.....

thanks

--JD

[N Hurst]

Do they define "stake"? I've seen some "stakes" for decking supports that are 4' long and weigh 15 - 20 pounds. You could probably drive a few of those into the ground, then bolt the arbor to them and have close to the same net effect.

-Nathan

[Tom B]

You don't say what the post material size is going to be.

If I assume 4X4 inch posts, you can drill a 5/8" hole at an angle in the side of the posts about 12" above the bottom and angled in to come out around the middle of the bottom of the post. You can buy a long drill (~18") at one of the Borgs to do this. Drive 48" of 1/2" rebar through the hole and into the ground, in effect toe-nailing the post to the ground. Depending on your soil conditions that could be enough to prevent sideward movement of the posts' vertical axes. As described, it seems unlikely that wind could generate much "lift" on the structure (no solid roof), so that shouldn't be a major problem.

Regards

Tom

[Zephyr]

Do your neighbors like or dislike you? I'd consider putting in the tubes to anchor it down and just hope that no one reports your "landscaping feature" to the township. Really, I'm not a die hard" keep the government out of my pocket" type person, but seriously. Taxing someone for building a grape vine holder is crazy. I'd go for the tubes though because with your vines on top, that structure is going to get fairly top heavy.

Dave

[nicksanspam]

Commercial plastic film greenhouses have 3' galvanized pipes as ground stakes, about 1.5" diameter. You put the end of the pipe on the ground, slip a bigass bolt into the top and pound it into the ground. Then slide a smaller pipe bow into the ground stake and put a horizontal bolt through 2 holes in each pipe.

Nick

[<josh]

I've seen this done for a motorhome shelter, where they were also trying to avoid a permanent foundation. The posts all set into brackets welded to the top of a foot-wide, half-inch-thick steel plate with beveled edges. Not much of a tripping hazard, plenty heavy and stiff, but still a temporary base that just sat on the ground.

[Arvid Sorsdahl]

[CC]

You could use the floating deck supports from Deck Systems. Bury the blocks part way to prevent lateral movement and they will support your 4X's or 2X6's. You are making the structure self supporting with legs down each side with bracing so there should be no problem with this system. I would think this system would work well for what you need CC

[<aemeijers]

Treated posts sitting on concrete or metal standoffs, so the wood isn't in direct ground contact. You do need to tie it down so it doesn't blow away. Mobile home anchors, or if you want to get fancy, have a welder make some square-section tubes to slip the legs into, with big augers like used for huge dog tiedowns attached to them (or even just bigass metal stakes), and holes for horizontal bolts through the uprights. Or, like the other guy said, just plant the posts like fenceposts or mailbox posts, cut the tops off even, and frame it up from there. I don't think things without solid roofs and/or panels (like sheds or fences) are considered 'structures' in most areas. Drive around the neighborhood, and see what the neighbors have put up- you can probably get away with the same.

aem sends...

[jd]

I think this one is the winner! I'll be using 6x6 for the posts (I did say timberframe....), and "toenailing" into the ground can't possible be considered a foundation...

Thanks a ton to everyone that responded....

--JD

[Tom B]

Shoot, can't believe I got one right!

Thanks for the thanks.

BTW - weather proof the bottoms as others have suggested - I use roofing tar - cheap and close to indestructible.

Regards.

[Michael J. Dale, P.E.]

wrote in news:cN9Bh.58389$ [e-mail]:

You can also buy precast foundation plinths that may or may not be taken as "permanent" by your local tax office.

Personally, I'd set to sonotubes deeply enough to cover them with soil and have a galvanized bracket set into them sticking up out of the ground. Tell the tax inspector that the bracket is just driven into the ground.

mjd