On Sun, 29 Aug 2004 08:51:45 -0700, John D'Errico wrote
(in article
):

Our house has vertical, rough sawn cedar siding, and
an attached treated wooden deck. (We live in upstate
NY.)

The problem is the way they attached the deck to the
house. They nailed a treated header directly to the
cedar siding, then ran joists off the header to support
the 1x6 decking. Several times a year I am forced to
carefully clean out this joint with the house, to get
any junk and leafy detritus out. Otherwise It stays
wet and we get carpenter ant problems. I use an air
gun from my compressor to blow out the mess from the
cracks. This takes a fair amount of time, and almost
killed my 4 gallon compressor last time i did it
because the compressor is running almost full time
for over an hour.

I do have access under the deck, where there is
between 1-8 feet of clearance around the house. The
deck butts to the house for about 60 feet around
one side.

[snip]

John -

The usual solution for this is to have a flashing which protects the top of
the ledger and the joint between the ledger and house. It's sort of a Z-bar
flashing - set and caulked into a 1/4" kerf cut in the siding above the level
of the decking. In cross-section, it goes down the wall over the top of the
ledger, then down the face of the ledger an inch or so. You notch it at each
joist. And install it in a bed of caulk. Here's an ASCII diagram which may
help:


| --- Siding
|
--+ -- Flashing
| |
| | +--------------------
| | | Decking
| | +--------------------
| +--------+
| +-------+|
| | || -- Flashing
| |Ledger ||
| | |
| | |
| | |
| | |
| | |
| | |


The first course of decking can be installed 3/4" away from the siding. The
resulting channel will still collect debris, but it's easy to wash away with
a hose.

You could make this fix by removing the first course, installing the flashing
and then cutting down the decking and reinstalling. A bit easier than
resetting the whole ledger as you propose.

I'm a bit concerned that the ledger is fastened by nails into the siding.
Without knowing the deck dimensions and beam/post layout I can't guess at the
weight on the ledger, but unless there's a beam VERY close, the ledger should
be fastened more robustly. The usual method is lag screws into the rim
joist, or other house framing, 2 x 1/2" lags every 16" or so.

Good luck.

- Kenneth