How to install a proper deck ledger AFTER the fact?

Question

We just purchased a house that has a roughly 10X20 deck on the back. It's relatively low to the ground (maybe 1-3 feet high).

The house is cedar lap siding.

The problem is that the deck was built improperly. It was attached to the house directly over the siding, so no proper ledger board, flashing or gap.

What to do? Is there a way to fix this without dismantling the entire deck?

My thoughts:

• pull out the floor boards closes to the house a foot or two out.

• jack/shim up the house-side joists from underneath.

• cut each joist away from the house a few inches.

• remove siding, flash, and install proper ledger.

• use deck spacers to the install a new 'hanging ledger (is that a term?) to connect to the new shortened joists with new hangers.

Seems doable, all except the tight quarters I'd be working in.

Has anyone done this? Tips/suggestions?

Another option I was considering as more of a short-term option:

• remove just one row of floor boards

• create new flashing from siding above the connection to the house, wrapping it over whatever type of ledger is below it.

That would basically be just using larger flashing. Might look kind of ugly, but would obviously be a lot less labor.

Answer 1

Ugh. Your plan sounds like a lot of work, but seems sound.

As an alternative could you convert this to a freestanding deck? Add post and piers near the house. Install some blocking to replace the crummy ledger you'll soon remove. Pull up your one row of floor boards and chop the deck shy of the wall.

Answer 2

Do your plan except cut the joist about 3' from the side of the house.

Install the ledger an then sister the removed joist section back into placed with 6' sections of 2x8 or 2x6 (whatever the joists are) with several nuts and bolts.

If the support posts really get in the way of this, then make the splice between the first and second posts instead of the first posts and the wall.

Unless the deck is terribly difficult to take apart (rusted/stripped screws), this project should only take about two days (50% of which would be installing the ledger and flashing) if you have an impact driver (or even a decent drill/driver) and a good set of bits (Milwaukee Shockwave bits... Dewalt Impact Ready bits are terrible [they break and have other huge problems too].)

Things to keep in mind:

1. Don't get the deck boards all mixed up, and they'll all fit back together nicely.

2. Try to make a nice, clean cut on the joists, don't get them mixed up either. Any additional cuts to adjust their length should be made on the side that joins up with the ledger. (This will ensure that the joists fit back together nicely at the splice.)

3. ???

4. Take pictures along the way and post them on the blog.

Answer 3

I have the same problem. This is what I am thinking of doing:

Cut back the siding above the ledger in two places - right at the top of the ledger and 1" above the level of the board that goes over the ledger. Loosen the siding left above the ledger so that you can slip flashing under the paper under the siding. Run flashing behind the siding and over the ledger as should have been done in the first place. This should work if the ledger and the siding under it is still in reasonably good shape and you have a good strong ledger connection to the house with lag bolts.

Be careful that you don't destroy the tar paper under the siding. Cut the siding just short of that depth and then have fun trying to pry the siding out.