# Door threshold flashing at deck



## kwerk (Apr 19, 2010)

I am about to install two doors that open to a deck (which is yet to be built) and I'm not sure how to flash the thresholds.

I understand how the z-flashing works for the rest of the wall but what happens where there is a door? The ledger is going to be 2" below the subfloor level so the decking is 1" below the door. I don't want to simply rely on caulking.

I am considering using something like suresill or jamsill under the threshold but how does that tie in with the deck ledger flashing?

BTW I am using zip system sheathing so there is no WRB just vycor plus tape.


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## Daniel Holzman (Mar 10, 2009)

Everything I have read suggests that the top of the deck boards should be at least two inches, preferably three inches below the finish floor elevation of the house. So you may be a little tight, but probably not a huge problem.

I am also building a deck at this moment, and had similar issues. Based on everything I have read and seen, the door flashing is independent of the ledger board flashing. I was planning to install door flashing using a copper trough system, in addition to the usual waterproof tape around the door. I was going to make my own copper trough, although I have found several manufacturers who make pre-built trough flashing for doors, and it looks pretty good, so I might just use a prebuilt piece.


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## kwerk (Apr 19, 2010)

Daniel Holzman said:


> Everything I have read suggests that the top of the deck boards should be at least two inches, preferably three inches below the finish floor elevation of the house. So you may be a little tight, but probably not a huge problem.
> 
> I am also building a deck at this moment, and had similar issues. Based on everything I have read and seen, the door flashing is independent of the ledger board flashing. I was planning to install door flashing using a copper trough system, in addition to the usual waterproof tape around the door. I was going to make my own copper trough, although I have found several manufacturers who make pre-built trough flashing for doors, and it looks pretty good, so I might just use a prebuilt piece.



I have a 2x10 rim joist and 2x10 deck joists. To have the deck boards 3" below the door, the ledger would have to be 4" down, which would end 2.5" below the bottom of the sill plate. Seems like all the bolts would have to be towards the top of the ledger to go in the rim joist? Is that OK?

I plan on using two Ledgerloks in each joist bay (16" OC joists). I am going to put blocking behind the rim joist, between the floor joists in the basement and use 5" ledgerloks for a bit of overkill.


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## Michael Thomas (Jan 27, 2008)

As you have not yet built the deck, consider building a free standing deck: simpler door flashing problems, no ledger support or flashing problems.










See the discussion here: http://www.diychatroom.com/f19/any-reasons-i-should-not-build-deck-before-door-76465/


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## kwerk (Apr 19, 2010)

The code says footings closer than 5' to the house need to be the same depth as the house footings which would be about 9' down for me. I also want to have full access to the siding/sheathing to replace it in a couple years.


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## kwikfishron (Mar 11, 2010)

I have stainless steel door pans made for all exterior doors a local sheet metal/HVAC shop for about $35 each. The pre-made ones rarely work for me due to the different sheathing and siding thicknesses.


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## Michael Thomas (Jan 27, 2008)

kwerk said:


> The code says footings closer than 5' to the house need to be the same depth as the house footings which would be about 9' down for me. I also want to have full access to the siding/sheathing to replace it in a couple years.


FWIW, The IRC does not specify a distance from the foundation wall, but rather that "‘Footings shall be supported on undisturbed natural soils or engineered fill" (R403.1).

In may area builders attempt to keep costs down by minimizing excavating, so you can often cantilever back to the wall from footings in "undisturbed soil".

If you decide that you want to go with a ledger attached to the structure, take a look at alternate ledger attachments such as the "Maine Ledger Bracket":

http://deckbracket.com/

which will reduce problems with ledger flashings both now and when you re-side in the future.


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## BigJim (Sep 2, 2008)

I make a pan out of aluminum flashing that you can buy a roll of at most any hardware store. I turn up the edges to the thickness of the finished floor and install under the door on the floor. The corners will have to be cut to be able to turn up, you can use a high water resistant sealer in the corners to seal the cut.

The outside edge of the flashing will lay over the top of your other flashing with a good sealant under the flashing.

It worked for me many times where I had multiple doors or single doors exposed to direct rain.


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