Best way to attach and flash deck ledger onto a house

[kennyb]

I'm looking for the proper way to both attach and flash a deck ledger to a house. I have read many aticles lately regardind deck collapses due to improper installation of flashing. Can anyone help me find what is the proper way?

[myvalk]

up in our neck of the woods, we lag bolt a 2x to the existing box joist of the house, good and solid, then flash over it with "z" flashing. it should go under the siding, then across the top of your ledger board, then down the face of it. so water runs off the siding, over your board.

[doyle]

Even better is to use carriage bolts, provided you have access to the back side of your house's rim joist. If you plan on having lots of people on your deck, don't be stingy with the bolts...put them between each joist, or at least every other joist. Be sure and apply caulk into each hole before using the lag screws -or- the carriage bolts just as an extra precaution against water infiltration.

[mjpliv]

There are hangers available for attaching deck ledge boards with no flashing required. Check with your local building supply store. They were used on a project of mine a few years ago, they seem to have worked just fine.

I also found this site for the traditional method

http://www.bestdecksite.com/introLedgerPg1.htm[/url]

[JCA]

I just put a deck ledger on our house. I installed flashing the full length of the ledger, and about 4" wider than the ledger, leveled the ledger and nailed, then installed carriage bolts every other joist along the top, and lag bolts every opposite joist along the bottom.

[Sweep]

I strongly recommend allowing water to flow down the face of the building past the deck. To interrupt this flow with a ledger on the face of the sheathing and rely on flashing to protect the wall is not a permanent solution. I have seen too many examples of rotted sheathing and band joists/sills when taking these things off.

There are heavy extruded aluminum "I" brackets that work very well.

http://deckbracket.com/

[Mike772]

Before I put up the ledger, I put up a run of ice & water that runs the full length of the ledger. That way if there is a chance of water getting past the flashing (ie. homeowner using pressure washer) it isn't doing anything. The ice & water seals up the bolt holes and any nails too.

[Sweep]

The ledger method creates contact between standing rainwater, metal flashing, and wood preservatives that should be avoided in a long-term solution. If you use this method I recommend taking the following precautions:

Sheet metal flashings perform poorly in this design because they are kept wet most of the time. Aluminum weathers extremely well because of the thin protective layer of aluminum oxide and hydroxide that forms in the atmosphere, but because of its relatively low "nobility" it corrodes rapidly when in prolonged contact with rainwater and/or wood preservatives developing pin holes not easily detected. Copper is much better because it is the most "noble" of the common flashing materials but will eventually corrode.

To keep the flashing dry, provide a minimum 1/2" space between the deck board closest to the house and the ledger flashing. Slope the flashing down and away from the house as much as possible. It should not be possible for the flashing to stay wet.

Placing "ice & water shield" behind the ledger will work if there is a space between the wall and ledger to allow water to move downward rather than finding connectors and penetrations by capillary action.

Put the "ice & water shield" over the top of the ledger before the flashing is installed. This not only provides back-up for the metal flashing, it also protects the flashing from the accelerated corrosive effects of the new wood preservatives (ACQ, CAQ-B, or ACZA) that have taken the place of CCA.

Because of the accelerated corrosion issue you should use heavy galvanized (HDG) steel connectors or WR Grace's "Vycor Deck Protector". Copper flashing might perform better since it is the copper in the preservatives that enables the electrolitic corrosion process but I have not yet seen any evidence.

Fastners for the ledger board should be large galvanized lag screws or thru-bolts instead of nails.

I still believe the aluminum brackets provide a more reliable and longer-term solution for less time and money.