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inspectorreuben

How to terminate ledgerboard flashing?

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In the photo below, there was water leaking in to the wall where the deck heights changed. I'm sure that water is running horizontally along the ledgerboard flashing and then dumping in to the wall where the flashing ends. I've found this defect on a lot of decks, but it's usually not this obvious.

Does anyone have any photos or diagrams showing the proper way to terminate the ledgerboard flashing to prevent this from happening?

I've gone through every archived issue of the JLC (only $45 for the DVD), and couldn't find a single article that dealt with this detail.

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tn_20114382433_DSC00844.jpg

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- Reuben

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I think it'd have to be done like an end dam, with a tailer that got the water out farther away from the house than conventional ledger flashing.

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Hi,

They should have integrated some self-adhering bituthene (ice and water membrane) into the flashings at the transition between the two decks behind the siding. I'd have used coil stock behind the whole thing and spacers like below.

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tn_20114395526_DeckToHouseConnection.jpg

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ONE TEAM - ONE FIGHT!!!

Mike

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Thanks Mike. That's a good drawing, but it raises a question about spacers behind the ledger board.

There is no longer any friction between the board and the wall, so all the weight transfers to the bolts or screws (I call the pointy ones screws [:)]).

Is it not a stronger construction detail to have the ledger board tight to the wall?

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Hi,

They should have integrated some self-adhering bituthene (ice and water membrane) into the flashings at the transition between the two decks behind the siding. I'd have used coil stock behind the whole thing and spacers like below.

Click to Enlarge
tn_20114395526_DeckToHouseConnection.jpg

79.86 KB

ONE TEAM - ONE FIGHT!!!

Mike

I like that idea better, although, the flashing should still have an end dam.

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Hi,

They should have integrated some self-adhering bituthene (ice and water membrane) into the flashings at the transition between the two decks behind the siding. I'd have used coil stock behind the whole thing and spacers like below.

Click to Enlarge
tn_20114395526_DeckToHouseConnection.jpg

79.86 KB

ONE TEAM - ONE FIGHT!!!

Mike

I like that idea better, although, the flashing should still have an end dam.

I will never see end-dam flashing on a deck in my area . . . not that it isn't a good idea.

I see decks flashed like Reuben's all the time and, even when there's no change in heights, water runs between the trim coil--which is overwhelmingly the flashing of choice--and the siding. The secret is having the lower portion of flashing act like drip-edge, as in Mike's drawing. But . . . I can't imagine I'll ever see that, either.

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Here's a picture of an end dam. This is from a piece of window flashing, but the idea is the same.

At it's heart, this issue isn't about flashing. It's about the basic intelligence and problem-solving skills of the installer.

Download Attachment: icon_photo.gif End Dam.JPG

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Thanks for the replies, everyone.

I'd have used coil stock behind the whole thing and spacers like below.

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tn_20114395526_DeckToHouseConnection.jpg

79.86 KB

In the August '03 issue of the JLC, they discuss using spacers like you showed above. They basically said this is a practice that should be avoided, but if you're going to do it, use the following fastener schedule:

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tn_20114316459_Fastening%20Schedule%20for%20ledgerboard%20with%20spacers.jpg

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Can you imagine anyone actually doing that?

- Reuben

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Thanks Mike. That's a good drawing, but it raises a question about spacers behind the ledger board.

There is no longer any friction between the board and the wall, so all the weight transfers to the bolts or screws (I call the pointy ones screws [:)]).

Is it not a stronger construction detail to have the ledger board tight to the wall?

Good question. A bolt generally has a much larger diameter than a nail and provides greater shear capacity. I question the contribution of friction in an arrangement where the ledger is nailed tightly in place. It's mostly just the nails versus gravity IMHO.

Marc

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While we're on this topic, what's a good way to keep water from leaking in where one piece of flashing ends and the next begins?

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tn_201143161123_DSC00841.jpg

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- Reuben

Make a butyl caulk sandwich.

- Jim Katen, Oregon

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. . . with spacers.jpg[/img]

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Can you imagine anyone actually doing that?

Download Attachment: icon_photo.gif WellBoltedLedger.JPG

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You did that install yourself right Jim? I'm lucky to see one 3/8 lag (too small) every 4-5 feet, in the center of the ledger board no less.

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. . . with spacers.jpg[/img]

38.79 KB

Can you imagine anyone actually doing that?

Download Attachment: icon_photo.gif WellBoltedLedger.JPG

88.58 KB

You did that install yourself right Jim? I'm lucky to see one 3/8 lag (too small) every 4-5 feet, in the center of the ledger board no less.

Ha, ha, ha.

No.

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just a note concerning coil stock and treated lumber. On the boxes of coil stock I've used it says not to use it in contact with treated lumber. I have seen coil stock rotted because of the chemicals in the lumber. Is there another type of coil stock?

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(see diagram) Cut the flashing long, cut at the solid red lines and bend at the dashed line. Use silicone where they overlap at the back.

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tn_20114402717_Flashing.jpg

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(see diagram) Cut the flashing long, cut at the solid red lines and bend at the dashed line. Use silicone where they overlap at the back.

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tn_20114402717_Flashing.jpg

27.88 KB

l like it. But it would be slightly better to place the blue section in *front* of the grey one. As you've got it now, any water that makes it through the vertical seam is a leak. If you put blue in front of grey, water could only leak through a single point instead of an entire vertical seam.

- Jim Katen, Oregon

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I like metal (copper) for some stuff, but nowadays I rarely use metal for this sort of thing.

40 mil self adhered allows forming the pan in ways you could never get metal to go. It also makes the interior back dam much easier on doors.

You can take a mess of angles and vertices like Reuben's deck, layer it all with 40 mil goo'ed into place, and that thing'll never leak.

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