Ledger Flashing

[Robert Foster]

I'm seeing more and more "flexible flashing" used at deck ledgers. A new home today and a new home last week both had it.

The new homes deck today was attached at the second floor level and the flexible flashing makes no attempt to return the water to the exterior surface of the vinyl siding.

I guess I'm old school and don't think it's prudent to rely on the water resistive barrier that vinyl siding manufacturers hide behind to keep water out of the underlying structure. I've always built on the assumption that any water that gets behind the siding is a mistake and should be returned back to the exterior of the siding as quickly as possible. The building code even touches on this idea as shown below. I'm going to write this up and wanted to see if I'm in the minority.

What's the consensus here among inspectors ? In your opinion is the flexible flashing shown in the attached photos significantly deficient or not functioning properly and warrant being written up as a concern?

In the photos the black is the flexible flashing and the white is the house wrap.

1405.3 Flashing. Flashing shall be installed in such a manner as to prevent moisture from entering the wall or to redirect it to the exterior........

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[Ross Neag]

RF,

It's difficult to see based on the photos but I get the gist of it--it's not properly installed. The flashing should extend over the ledger to begin with let alone what we cant see. I've seen the peel and stick copper flashing used that is a cheap way out but will suffice if properly installed.

[chris mcintyre]

The flashing should come out and over the J-channel, that would be the reason not to use the flexible flashing because it would be susceptible to damage that would then let water behind the siding.

Here is an illustration I use to show people how a deck should be flashed.

Hard to tell for sure from the pictures but the rim joist attachment (or lack of) appears suspect.

[Ross Neag]

Nice diagram Chris,

Despite our intention to live in the real world, based SOLELY on that diagram, would the base flashing labeled #1 beneath the ledger be redundant? Again, I'm all for belt and suspenders, just asking the question if it weren't there and what you'd call out on a report/field view. We in Chicago are lucky to see the top flashing 2 out of 10 times. No joke.

[chris mcintyre]

.....would the base flashing labeled #1 beneath the ledger be redundant?

Robert said this deck was attached at the second story which is why (IMO) both z flashings are necessary. Without the lower one water running down the ledger could get behind the siding, without the upper one water could penetrate at the fasteners between the ledger and the house.

On a deck where the bottom of the ledger is on the outside of the foundation wall I agree that the lower z flashing is not needed.

We in Chicago are lucky to see the top flashing 2 out of 10 times.

Same here.

[Jim Robinson]

Nice diagram Chris,

We in Chicago are lucky to see the top flashing 2 out of 10 times. No joke.

I rarely see any deck ledger board flashing here.

[Bob Knauff]

In your opinion is the flexible flashing shown in the attached photos significantly deficient or not functioning properly and warrant being written up as a concern?

Absolutely. See attached image of proper flashing installation. Your deck set up channels water behind the ledger and the siding asking for trouble very soon.

Also, the ledger board appears to be only a 2 x 4 size?

[Robert Foster]

I have and use the same ilustration that Bob posted. I got it off this site and if it was you Bob who originally posted it...thank you.

As Chris mentioned this is a second floor deck and I agree the Z flashing is needed here at the bottom edge of the ledger, while not at a first floor deck where the flashing overlaps the foundation wall. I have the below illustration for first level deck ledger flashings...and once again thanks to whoever on this site originally posted it.

The ledger board is actually a 2x10 with 2x8 joists

The rim joist attachment was suspect and made more so by these pictures because the inner board you are barely able to see is a 2X8 while the outer board is a 2x10.

I originally received a call about this house several weeks prior to inspecting it and I stopped by on my way home from another inspection. While walking around the exterior of the house I noticed several defects with the deck. Fast forward three weeks to when I did the actual inspection and some, but not all of those deck defects where repaired. The client told me the county inspector had been out there and pointed out several things on the deck that weren't going to pass the C of O, which the builder remedied.