# Need help regarding a freestanding deck



## healthyhomes (Mar 14, 2008)

Hey guys,

I have been asked to build a freestanding deck. I havent built a freestanding one before, but understand it, and it really isn't much different. My problem is, the guy wants to put a roof over the entire deck. It is a fairly big deck 24' x 16'. If thats not enough the ground is really muskeggy crap and has alot of movement, and the local building code doesnt allow any excavation for footings or piles. We have to do concrete pads on grade. 

My first thought is it's a bad idea. If anyone has had similar experience please let me know! If you have built a roof over a freestanding deck please let me know how you did it briefly.

Thanks


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## seabolt (Feb 2, 2008)

That sounds like a bad idea to me too - is there any particular reason that code doesn't allow for footings?


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## healthyhomes (Mar 14, 2008)

no digging alowwed in the area... it's a cottage area. sticky rules


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## neolitic (Apr 20, 2006)

Would normally just do it like
a pole frame, but on muskeg?
Dunno....
Can you drive piles?
Is there a bottom?
Romans drove piles for the
Rhine bridge with timber A-frames.
There are small tractor mounted rigs.


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## healthyhomes (Mar 14, 2008)

cant drive piles either


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## Jason Whipple (Dec 22, 2007)

Could you use a ground beam? It's basically a concrete curb with re-bar in it, poured directly on the ground. It could be poured to any height you need just flair the bottom as needed. Should work just as well as a slab and with less work and materials (in most cases).

I use this technique for low decks that would require a wood beam to be mostly under ground.


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## BuiltByMAC (Mar 11, 2006)

2 questions - 

How high above grade will the deck surface be?

What is the thought process behind building something on footings that are *above* the frost line? You're in Canada, what's the frost line? 2'..3' down?

Mac


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## Brock (Dec 16, 2007)

Run Forrest run.


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## neolitic (Apr 20, 2006)

BuiltByMAC said:


> 2 questions -
> 
> How high above grade will the deck surface be?
> What is the thought process behind building something on footings that are *above* the frost line? You're in Canada, what's the frost line? 2'..3' down?
> Mac


Farther north they "float"
buildings on the permafrost.
Maybe need to check into their
techniques?
Maybe a waffle slab?


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## robert c1 (Mar 11, 2007)

Obviously it sounds like a bad idea. But that's not really our call.

My understanding of muskeg is a highly saturated biomass/soil with a pretty severe freeze thaw cycle. If you cant dig below it then your goal is to build something that moves together.

My thought would be to lay a web of really big PT timbers on grade and try to disperse your point loads as much as possible. If this is adjacent to a house have as much seperation as possible. 

The more I think of it, there's no way in hell I'd do it without hiring an engineer. Let him be responsible for the design.

Another thought is to talk to the local building inspector. If they don't let you dig, but they do let you build there has to be accepted workarounds. Around here anything with that much water in the ground is a sacred cow and requires a 300 foot buffer.


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## healthyhomes (Mar 14, 2008)

BuiltByMAC said:


> 2 questions -
> 
> How high above grade will the deck surface be?
> 
> ...


 
It will be approximately 36" above grade. Frost line is 4' down.


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