Max cantilever for deck joists?

[AdironDoc]

There's a forested bluff atop a hill not 600 feet from my main cabin where the view is nice and the breeze really blows. The path up is gentle but it overlooks the creek from maybe 60 ft up the steep side. I thought I might put up a simple shed style bunkhouse with tilt up panels on both sides and simple screens for windows. Just large enough for a couple of cots and a deck large enough for 4 camp chairs where I could watch the sun go down and catch a cool breeze on a hot summer night. No permit needed for sheds or structures under 12 x 12. I was thinking roughly 8 x 10 with similar sized deck.

Here's the rub. To maximize the view through the trees, I'd like to get the deck as close to the edge as reasonably possible, where the ground suddenly changes from 10 to 15 degrees to what I'll guess is a 50-55 degree grade (I had a heck of a time climbing it but managed by grabbing the grass). Rather than wrestle with superlong support posts, I'd rather hang out just a tad by cantilevering the joists. Is there a reference showing cantilevers? Anyone dealt with putting a deck out over a steep grade? Tips on a simple bunkhouse for an over-nighter? Any comments appreciated.

[Rob_O]

This should help

http://countryplans.com/smf/index.php?topic=11881.0

[AdironDoc]

Thanks for the link, Rob. Didn't see that thread in my post search then I noticed it had been posted after my search!

Doc

[MountainDon]

I think the big concern here is the row of piers that the deck is cantilevered over. The way it is drawn the piers appear too close to the slope. A month ago I first heard of the 7 foot rule. In words, in means; On steep properties, the slope of the ground around the footing could affect the footing's stability.  The 7-Foot Rule states that there should be a least 7 feet between the bottom of a footing and daylight.

From Inspecting a Deck, Illustrated - InterNACHI http://www.nachi.org/deck-inspections.htm#ixzz1mz7V3Iz9

[MushCreek]

I'm certainly no engineer, but my first thought is to put a diagonal brace from the edge of the deck back to the base of the post.

[MountainDon]

see IRC section R403.1.7   footings on or adjacent to slopes
http://publicecodes.citation.com/icod/irc/2012/icod_irc_2012_4_sec003_par012.htm



What you propose seems to fall outside the prescriptive limits. What you have probably covered bt the following...

R403.1.7.4 Alternate setback and clearances.
Alternate setbacks and clearances are permitted, subject to the approval of the building official. The building official is permitted to require an investigation and recommendation of a qualified engineer to demonstrate that the intent of this section has been satisfied. Such an investigation shall include consideration of material, height of slope, slope gradient, load intensity and erosion characteristics of slope material.