Deck with planks perpendicular to house?

Started by MushCreek, April 29, 2014, 11:48:02 AM

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MushCreek

I've been reading all of the latest rules on deck building, but I want to be difficult and have my deck planking perpendicular to the house. This puts my joists parallel to the house. Most (all) of the decks I see are with the joists perpendicular to the house. I have a 2X12 PT ledger bolted firmly to the house, but there would only be 2 members attached to this, going out to the rim joist. The joists would hang off of these. What keeps those two members from pulling away from the ledger? It doesn't seem like joist hangers would be strong enough. Does the actual deck planking count? Certainly all of those deck planks attached to the ledger offer some strength. I'm going to use composite decking, if that matters.

The deck will be 10' long, and extend 8' out from the house. Then, I'm going to build another section 18' long that would extend 5' from the house. Should I just build the deck as a free-standing deck, with posts on the inboard side as well, and just use the house attachment for stabilization?
Jay

I'm not poor- I'm financially underpowered.

JRR

I'm not sure I totally understand the framing plan, but be sure to check the allowable joist spacing for the decking you plan to use.  Some brands that I have read of are limited to a joist spacing of no more than 16" ... some may be even more limited.


Adam Roby

This might not be the best option, but you might consider some furring strips (say PT 2x4's) and attach the decking to those?  This would keep your girder/joist locations in their conventional positions.  I would guess 16" OC would be the way to go.  Just have to account for your height being 1.5" higher than expected.

Don_P

your ledger attachment likely cannot handle the point load of the perpendicular girders. I've done these on posts or piers, you can also look into high capacity girder hangers that attach to the fully supported house rim... but I'd go freestanding. The pics of the 12'x75' porch I posted awhile ago was done freestanding and with perp decking. I prefer this orientation, it looks better and drains better but it is more difficult and can give inspectors heartburn. There is a ledger that the boards use and the girders are attached to which is fastened as a conventional deck.
This decking orientation is actually conventional porch construction.

MushCreek

That's true; it is like a porch. I see your point about the point load on the ends of the ledger. I guess I'll add inboard posts, and brace the posts to make the deck self-supporting. It's going to be 8 feet off of the ground, so it needs to be strong.
Jay

I'm not poor- I'm financially underpowered.


Don_P

Found some on an old stick
girder posts visible at house, first section of mudsill and rim on outer edge stone wall to show the mason what I was thinking. The posts are bolted to the house rim for bracing and were instaslled to the footing prior to backfill;

girders over posts and joists in, not visible, a treated scabbed on pair of 2xs connecting post to girder;

decking on;

Grimjack

Not to thread jack, but Don P, could you point me to thread those pics came from? I love the look of that house with the huge deck! Thanks!

MountainDon

That was a project Don_P was the lead on, built for someone else. It is a very nice house.
Just because something has been done and has not failed, doesn't mean it is good design.

MushCreek

Here's a quick sketch. The framing members will rest on top of the 6X6 posts, but aren't drawn that way for clarity. I figure I need 9 posts. The reason for the long narrow part of the deck is that eventually I am going to build a free-standing porch off to the left, which will connect to the end of that walk-way. Spacing on the joists is 16" for the composite decking.

My footing extends out about 6" from the basement wall, so the posts up against the house could rest directly on the footing for bearing. I could fasten them to the ledger at the top. I can't (structurally) fasten them to the basement wall, as it has foam over it from the ICF. No need to anyway. The posts at the house will take care of the vertical loading, and I can put in diagonal braces on the posts to prevent the deck from moving away from the house. I'm sure the decking will serve that purpose as well, but I'm talking code compliance here, so I'll treat the deck as free-standing, despite being connected to the house. They've gotten VERY fussy about decks in recent years.



Jay

I'm not poor- I'm financially underpowered.


rich2Vermont

I'm not sure whether it's helpful, but I did something pretty close to what you're looking to do. My deck extends only 5 feet, but I wanted the look that you might get from an old fir floor on a porch. I doubled the end jousts for strength as well as more area to run the outside "picture frame" of the deck boards. On the outside edge, I have a rim joust, but accounting for the overhang, I knew I'd need another joust to screw the ends of the deck boards to. Here's a couple of pictures that might illustrate it:





I didn't have to worry about inspection (or permits), but it's all very solid. My only regret is that I didn't buy the decking a month before laying it down so it'd be drier.