Water Damage Under Siding (Advice?)

Here are some photos that illustrate my questions: http://www.caliber.com/test/jamie/waterDamage /
Misc Info: 1. Our house was re-roofed fairly recently, so this water damage may have happened before the new roof (maybe because of improper chimney/roof flashing?).
Questions: 1. Do I need to do anything about the few inches of rotten rim joist? (Fig 3)
2. There were giant ant colonies between building paper and wood sheathing (and we have also had ant problems in the kitchen -- that's the kitchen behind the patio door). Is there anything I can do to prevent colonization, or is that something I just have to live with?
3. It looks like the builder used exclusively small pieces of plywood for the sheathing. Why is this? Is this best practice (to allow for expansion/contraction, or something), or is this shoddy workmanship?
4. There are gaps between each patch of sheathing, and if I were a bug, I would have no problem infiltrating our house. Should these be caulked, or should I do anything about this? Should I put larger pieces of plywood down in place of the small pieces that I will have exposed?
5. What's the best replacement for the building paper that's there now (the ants love it)? Should I use Tyvek anywhere?
6. I'm assuming I need to sheath/paper over the door opening (Fig 5)? Anything else with regard to the door opening?
7. Do I need to flash, caulk, or otherwise waterproof the bottom of the sheathing where it overhangs the sill plate? There is nothing really there now, just somewhat overhanging building paper.
8. Do I need to caulk the seam that runs vertically along the chimney? If so, would it be between the chimney and the new sheathing, building paper, or maybe Tyvek?
9. Is there anything that I've missed that I also need to do?
Thanks!
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Lot of questions. Lot of problems. It is hard to make definitive judgments from just a couple of pictures.

The damage in figure 1 is a little bit of water over a long periond of time. Most likely caused by improper flashing at the roof level or where the siding meets the chimney on the vertical rise. You haven't solved your problem if it on the roof because that is not a proper flashing job depicted in pic 6 or 8. MAYBE they installed the proper step flashing under that mess but they sure as heck did the over-flashing wrong. It should step up and be tucked and mortared into the joints of the chimney not just nailed and caulked.

If it truly is only a few inches you should be able to skip the repair provided the floor joist that ties into the sill at that point has not been damaged. Get it well dried before you cover it back up.

Get rid of the moisture, the ants will leave for a better place. Kill them with spray to hasten the process.

No clue filled in around the chimney with the cutoffs? Who knows?

There should be a small gap between the plywood sections. Do not caulk.

The ants love the moisture. 30 # felt paper is fine if proper installed (ovelapped like shingles so that any water that does get in is shed off). Spend more $ for other products if you like.

They should be a layer of building paper under all the siding installed as stated above.

The bottom layer of paper should pass below the top layer of block as should the siding. Best not to caulk. Any water should be allowed to escape not puddle.

Absolutely. That is where most of this damage came from. Other may dis-agree with this statement. I fit the felt as tightly as I can and caulk with a high quality caulk BEFORE I install the j-channel and then install the channel and caulk again. There is a somewhat new sealer tape designed for use around windows that would also work well for this. The name escapes me at the moment.

Get the roof flashing corrected or you will have much bigger problems later.

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Looking at the photos its hard to see if the chimney is flashed properly. It looks like they may have covered the stepflashing with an aluminum decorative piece. It seems like the upper edge of this piece is not inserted in the motar of the bricks to keep water from getting behind it.I would if that is the case remove that white material and see that it is step flashed underneath it. 1. I would cut out 32" or 48" of the rim joist next to the chimney. It's no big deal to do and will give piece of mind. 2. You should be treating the ground around your foundation a couple times a year with Diazinon or some equivalent. It comes in powder form. 3. There is no reason for the builder to have used small pieces of wood. What it looks like to me is that this water problem may have exsisted since the house was built and there have been repairs made before. 4,5,6. If this were my house I would remove the siding to the bottom of the windows. Remove at least 48" of plywood on the whole side and replace it with a good agency certified exterior plywood. Repair the damaged rim joist as stated above. and cover all new wood with Tyvek making sure that you tuck the tyvek under any existing building/tar paper at the top at least a few inches. The side of the chinmey where the door used to be you could remove the siding all the way up and install tyvek all the way up. Not really nessesary as you have a large over hang on the roof that keeps most of the water of the house. 7.No need to do anything where siding overhangs the sill plate just make sure it overhangs it by at least an inch minimum. 8. You can remove the J channel which would mean removing the siding all the way to over hang on that side of the chimney as well and see if there is enough space between brick and playwood to insert Tyvek or tar paper or both, tyvek first then tar paper over it,in at least 3 inches behind the brick. If there is no room butt the Tyvek to the brick and run a bead of caulk along the brick. Again you have a large roof over hang so this may not be nessesary. 9. From the pictures it looks like your sliding door was not flashed properly also. You need to get a piece of flashing between the door threshold that will come out the 1 1/2 inches for the Ledger for your deck and then fold it over the ledger at least half an inch to prevent water from getting behind that. Bit in my opinion what you need ot do first is check the chimney flashing as stated above and repair it properly. If it isnt step flashed you can either have someone do it or do it yourself. It involves getting a saw with an abrasive blade and cutting slots into the motar of the bricks at the various heights all around the chimney. Insert the lead flashing in the slot at least an inch and motar it in. The other end of the flashing will slip under each corresponding roof shingle starting at the lowest point. It's not gonna be easy but I've done it before. You just need patience. Good Luck!
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Junxies wrote:

Hoo boy. You need a qualified contractor, bud.

From the looks of it. Didn't anybody see damage when the old roof was opened up?

I sure would.

If it isn't moist, it won't be as inviting, for starters. Also look at the environment directly surrounding the house. Long term, deal with an exterminator.

Looks odd to me, like a jerry-built or repaired job. I would vaguely guess, based on what you've uncovered, that the whole wall was redone to accomodate a larger chimney or something similar.

As long as the siding's off, why not replace? It won't cost that much to get a couple of 4x8 sheets of OSB.
Sheathing isn't normally caulked; that's the job of the vapor barrier. Which brings us to ...

Tyvek, or any other type of house wrap. Building felt is still used, actually, but I don't know if it meets code everywhere.

If it has a solid sheathing already, just run the house wrap over it.

Caulking is recommended here, I believe.

Between the sheathing and the masonry.

That's what you need a contractor for. You've already seen a little job turn into a big one ...
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Depending on how handy this guy his he should be able to do it all himself and besides a contractor wont take the time to do it right and if they did you couldn't afford it.
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