Replies

1. 
   john7g | Oct 16, 2008 05:11am | #1

   1 piece (bottom purple) behind the ledger (band) set on top of another piece (red)that will kick out any water that get's behind the ledger and (keeps it from getting into the framing.

   Install ledger

   Another piece of flashing (blue) at the top of the ledger kicking water out before it get's behind the ledger.

   View Image

   
1. 
   davidmeiland | Oct 16, 2008 05:13am | #2

   Nice drawing. I would add spacers behind the ledger to keep it at least 1/2" off the wall behind.

1. 
   john7g | Oct 16, 2008 05:22am | #3

   Thanks. (SU is fun)

   I've done the spacers trick as a repair to a chimney chase/deck intersection and I don't think I'm completely sold on the process.  Flashed like the pic I'm not sure I'd get an advantage out of the spacers.  My thought as I finishe that job with spacers was "What a great place for hornet nests."

1. 
   davidmeiland | Oct 16, 2008 05:47pm | #6

   I think it's worth planning for the failure of materials. Eventually the Z flashing may rust to the point where water is getting behind the ledger, and then you're depending on whatever wrap you have used, which for a lot of people is Tyvek. That will not keep your wall dry. Things look great the day you build them, but 15-20 years down the road is a different situation. I have done a number of deck repairs recently (last 1-2 months) and the majority of the parts seem to last about 25 years. The parts that are sandwiched or otherwise installed in a way to trap moisture don't make it as long. Given that the Z flash at the wall will be permanently covered in leaf litter and whatnot it might be an early failure, especially if a typical painted 29ga galv piece is used. Of course you can get better metal flashings but what does the average person use?

1. 
   john7g | Oct 16, 2008 10:09pm | #10

   I wholeheartedly agree we ought to build it as good as possible but the reality here in the hot humid South is that standard PT decks don't last 25 years.  More like 10 if you're lucky.  The structure usually lasts longer but the decking is a goner at 10 and in some cases only after 5-8 years depending on how it was maintained (or not).  But either case the flashing willprobably get a good look-at during the replacement of the decking. 

   I think this is more of a geographical variation in mileage (YMMV) than better or best practices. 

   We ought to be getting into ACQ deck repairs before too long and that should prove to be interesting. 

2. 
   Piffin | Oct 16, 2008 05:37am | #4

   Excellent drawing!I saved it to disc here. 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

1. 
   john7g | Oct 16, 2008 02:09pm | #5

   Thanks

   If you're going to keep it, here's a better one to save that is more accurate (siding on stud walls instead of CC wall (I was in a hurry)) and better resolution.

   edit to crrect spelling

   Edited 10/16/2008 7:18 am ET by john7g

1. 
   Bing187 | Oct 16, 2008 05:58pm | #7

           Great drawing, excellent detail... I would only add that if using aluminum flashing where you have indicated in purple, and also for the 2 z flashing details, I cover w/ Grace. As far as I've been told, acq will eat up the flashing otherwise. Pretty sure this would apply to galvy as well, since the hangers and whatnot are supposed to be ss or hot dipped to prevent corrosion. SS bolts too.

           The way you've drawn this is exactly the way I've been doing it for about 15 years, and I've seen some up close recently, and still look good. I do usually leave siding up 1/4" so it doesn't trap too much leaf mooge. I think that with the exception of an I beam shaped bracket that I've seen on here, I'm not in favor of spacing...If it's flashed as you show, nailed w/ 16d, and bolted, it is much stronger, and shouldn't ever get wet behind.

   Bing

1. 
   john7g | Oct 16, 2008 10:15pm | #11

   I keep forgetting about I&W on the joists but haven't had a deck job in a while.  Thanks for the reminder. 

3. 
   dotto | Oct 16, 2008 06:02pm | #8

   Good drawing.  Sketchup correct?  It rocks. 

   I've never been sold on spacers either.  Flash it right, and it shouldn't get water behind it.Dave Otto -- Otto Construction -- PA

1. 
   mike_maines | Oct 16, 2008 07:36pm | #9

   I like to space the ledger not to keep water out, but to let debris fall through.  I can't stand the "leaf mooge" that gets in there and can't get out.

   Usually we solve the problem by running deck boards perpendicular to the house, joists parallel to the house, the way they did on old porches.

2. 
   john7g | Oct 16, 2008 10:18pm | #12

   Yes, SU = Sketchup. 

   I started using it when I realized the value of pictures over verbal or written instructions.  I've been south of the Mason-Dixon line since '85 and there's still dialects of Southern I can't communicate easily with.