Deck framing against cabin

Started by OlJarhead, April 28, 2014, 08:13:04 AM

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OlJarhead

So I have a question that I thought to ask in my cabin thread but decided to ask here instead as it might be useful:

As some of you know I built my cabin on a post and pier foundation and am now working to add a new foundation on the outside edges to improve stability and strength.  My plan is to pour a footing and build a surface bonded cinderblock wall on top of the footing to get 8" above grade then I plan to build a wood framed 'pony wall' between the cinderblock wall and the bottom of the cabin.  Once done I should have decent support for the walls etc and should then be able to 'hang' the roof of my deck off the outer walls.  This is something I could not do before improving the foundation.

My questions are these:

1.  I'm assuming I would attach a ledger to the outer wall of the cabin but I'm wondering if I should support it with some 2x6 mounted flat to the outer wall and under the ledger?  Securing the ledger to the studs of the wall and setting it on top of 2x6's should provide decent support right?  Is there a better way?

2.  Should I remove the siding where the ledger will be secured to the walls?  How about the sheathing?  (my walls are sheathed in 5/8" OSB and then sided with 1/2" T1-11 rough sawn siding)

3.  Does anyone know of a rafter hanger for 2" rough sawn lumber? 3" 4"

4.  Rafters:  I need to keep these as shallow as possible as I have a very limited space for them.  I plan to frame the deck roof as near to the original wall tops as I can but believe I'm likely to only get the rafters to 9 feet off the bottom of the cabin floor.  If I lower the deck 7" (to get below the cabin floor joists) that gives me 9'7" from the deck to the top of the deck roof and with a 10' deep deck I'm looking at a pitch of 2.5/12 I would have about 1 1/2" of room to play with (based on Easy Rafter calcs).  So to meet any kind of snow loading strength requirements I'll need a LOT of 2x6 rafters OR I can make them rough sawn (add about 25% strength I've read) or better yet go with 3x6 or 4x6 rafters.  I'll have to use a calculator but I'm thinking with rough sawn 2x6 I'd likely need 12" centers and assuming 4x6 isn't any more then 2 times the strength of a 2x6 then I can't see gaining there.  Perhaps another option is 6" logs but finding enough uniform 6" logs might be a challenge.  So, thoughts?  Ideas? Suggestions?

My plan to frame the deck is as follows:

Hang a ledger on the pony wall (inset) foundation and use simpson floor joist hangers to mount the rough sawn 2x6 floor joists.
Set a 4x8 beam on 4" posts set on adjustable pier blocks at 5' from the wall, then set another 4x8 beam on post and piers at 9'6" from the wall (outer edge of the deck, leaving a 6" cantilever)
Frame the deck with 2x6 rough sawn Doug Fir and cover the deck with 2x6 Doug fir and Ponderosa pine 'decking' (rough sawn also)
Set log posts on top of the 2x6 decking and lag bolt them to the deck (logs will be a minimum of 6" diameter at the small end and both Doug Fir and Pine).
Set 4x6 beam across the posts as a 'header' at a ceiling height of 7' off the deck.  (this smaller 'header' will likely require post spacing of 6' or less).
Frame the roof with rafters as mentioned above and sheet with 1" pine and fir.

I'll do mortice and tenon railings which will have to be assembled when the posts go in.

Thoughts? Concerns? Ideas?

Thanks!

OlJarhead

No Takers? LOL


Here is a very quickly done Sketchup of the deck I'm trying to build.

You can see the ledger and some 2x's laying flat against the outer wall of the cabin to provide it support (it will be secured to the outer edge of the 2x6 wall over the OSB sheathing and perhaps the T1-11 unless I should not do that??

Of course I'll have more supports on the outside edge of the deck for the roof but this was a quick markup to try to show what I'm up to


John Raabe

I'll just make a suggestion about the house wall to deck connection. You should cut back the siding and provide flashing up under the building paper and down over the new deck ledger

(You can use ledgerlok screws)

ledgerlok

Attach these screws to the studs and/or rim joist. This will keep water from running down into the wall. Once the ledger is installed you can carry the joists from hangers or an added ledger the joists can bear on.
None of us are as smart as all of us.

OlJarhead

Almost looks like they nailed the joists to the ledger before screwing it into the wall and ran the ledger over the siding.

I like your idea though of cutting back the siding and using ledgerloc's to lag screw it to the studs (2x6 on 16" centers) and using hangers. 

And I'm guessing that since I'm building a new foundation under the cabin walls I won't have to add additional ledger support with this setup.