Self leveling deck?

[joe greiner]

Righto, Mick. Not very easy to find around here, either. The smaller sizes are typically sold for hurricane tie-downs for mobile homes. The larger helical pier anchors (like these: http://www.abchance.com/ ) might be hard to turn by hand for later adjustment, especially lying on your belly.

I had some smaller surface roots to penetrate. Easier to advance after I got past the roots. Upon reflection, mine didn't have pipe tees at the top after all; just a short channel with the throat facing up and opposing holes in the flanges. Would still enable a good pier connection.

Joe

[Bleedin Thumb]

The system I had in mind was to use the anchor to tie 1.8m high treated pine posts in the ground then have a steel cable running through the top part of the posts (possibly inside a steel sleeve) this cable would flaire out at about a 45 deg angle and attach to a floating bearer on either side of the post, these would encircle the deck inside and out and each cable would have a turnbuckle for adjustment.

So its sort of a circular suspension bridge.

The only issues I can think of is if the "bridge" can move/sway I would have to ensure that there are no entrapment /crush points where hands or feet can get caught, so the posts would have to sit a bit away from the deck. The post ideally would be mounted with a backward rake to counter the forward forces of the cable - is that clear?

What do you thing, will it work?, will it look funky or ugly???

[journeyman Mick]

BT
what's the purpose of the suspension? If the anchors are moved by the roots it will still throw your levels out. Like you said, it introduces problems with potential pinch points plus chafing of cables. Also, will it need handrails and/or access steps? If so this will further complicate things. Screw in anchors with sliding posts for adjustment with a conventional bearer and joist construction will be straight forward and hassle free.

Mick

[joe greiner]

I guess we're a bit unclear about how high above ground the deck is intended. Also, is the terrain flat or sloping? Those might enlighten more suggestions or clarifications.

Joe

[silentC]

Nah, I like the hanging deck idea better. The kids will love it if it swings a bit. Erect some poles a few metres out from the base, string some cables between them and hang the whole thing off it. Yee hah!!

[Bleedin Thumb]

Yeh Silent thats what I'm picturing. It would be very easy to level with the turnbuckles.
Joe the grounds level and the deck will be just high enough so it clears the ground to keep the kids from getting under it.

If you set your poles in at 25 Deg off vertical (leaning out & away from the deck) you could possible get about 300mm between the posts and the outside of the deck so no worries about entrapment points.

I guess the next consideration would by aesthetics ...
you would require 6 posts inside and 6 posts outside...if they were TP you would probably use 150mm rounds this may look a bit chunky.

[pawnhead]

Sounds like a bit of a crazy (read expensive) idea to me. You'd want to have it engineer designed and certified. Imagine if a cable snapped and started flying all over the place, whilst a bunch of kids were jumping up and down on the thing.

[silentC]

Here you go: http://www.canopyaccess.com/English/...CCADesign.html

[journeyman Mick]

Having a moving suspended deck will increase the loads on the piers, increasing their sizes and, of course, the cost. Besides being different and maybe a bit "funky" I really can't see any advantages. (BTW do yoju know what the word "funky" originally meant/still means? ) Also a moving deck will incerse loadings on all the fasteners and I'll bet that it wouldn't last nearly as long before boards started popping loose.

Mick

[silentC]

Spoil sport

[Bleedin Thumb]

Sounds like a bit of a crazy (read expensive) idea to me. You'd want to have it engineer designed and certified. Imagine if a cable snapped and started flying all over the place, whilst a bunch of kids were jumping up and down on the thing.

Crazy...well..outside the square perhaps.

Expensive.... besides the cable (wire rope) its just like any other deck (kinda).

Engineers certificates aren't that expensive and I have a realistic construction budget....playgrounds are expensive! I would guess that I can get that deck built for under $5K which is a bit over the top per sq.m but for a piece of play equipment its cheap as chips.

Actually its not play equipment it is a multi-functional outdoor playspace specifically designed to enhance the gross motor skills of the user whilst acknowledging and protecting the natural assets of the site.

Ps Great site Silent, well I'm not to sure yet as I have gone over my bandwidth allowence for the month and I'm being punished by having a download speed impossed on me that was not even acceptable 12 or 13 years ago... I feel like a naughty boy...

Anyway next month I'll get into it and over-engineer this bugger!

[silentC]

it is a multi-functional outdoor playspace specifically designed to enhance the gross motor skills of the user whilst acknowledging and protecting the natural assets of the site

Even I'd pay $5k for one of them!!

[Bleedin Thumb]

Having a moving suspended deck will increase the loads on the piers, increasing their sizes and, of course, the cost. Besides being different and maybe a bit "funky" I really can't see any advantages. (BTW do yoju know what the word "funky" originally meant/still means? ) Also a moving deck will incerse loadings on all the fasteners and I'll bet that it wouldn't last nearly as long before boards started popping loose.

Mick

Ok it will be a bit more expensive than a normal deck. But I don't want normal and the client isn't pinching pennies.

As far as longevity goes that is only governed by the engineering and construction standards.

Maintenance of these things is a real problem in these environments. In 5 , 6 or 7 yrs time when I'm long gone no one is going to crawl under a deck to adjust it (infact no one will be able to get under it for safety) but they may see that its lopsided and a parent will see the turnbuckles and say I can fix that...well I hope anyway.

Please don't tell me about funky I'm sure that I don't need to know.

[journeyman Mick]

... I feel like a naughty boy...

You are!

Oh well, if the budget allows then it would be an interesting exercise. Doesn't sound like something that could be built for $5K though, maybe I'm just too expensive nowadays.

Mick

[joe greiner]

Interesting link, silent. Downloaded for future examination. But it's for a two-dimensional analysis, and this application would have out-of-plane components. I'd be inclined (no pun intended) to use an even higher safety factor on the cables. The sloping cables arranged around the perimeter would probably prevent any wobbling of the structure, as much fun as it might be. As to cost, I'd estimate the engineering fee alone could be well above $5k - full-blown CAD, finite element analysis, etc. No standard designs available that I can think of. Having the deck bearing directly on posts (inner and outer rings) would be much easier to design and build; could even use standard span tables.

Shallow foundations in the root zone would of course need adjustment. But if the ground anchors were embedded below the roots, I doubt there'd be very much long-term movement.

Joe