With all the changes in pipe size, it sounds like you may be trapping condensate that is supposed to be able to drain back to boiler, be collected near the bottom tee with the drain hose and sent to a trap. Your boiler as you describe (and I am very familiar with) should have been done as follows: The pipes (intake and exhaust) are 2" at the connections (2-1/2" in diameter) These should immediately be upsized to 3" PVC (3-1/2' in diameter) from there the 3" PVC intake and exhaust should travel outside with no further upsizing or downsizing taking place. From there the intake and exhaust needs not to stick out too far outside unless there is a snow clearance requirement or some other strict variables allowed. Also the pipes should be within 16-24" inches of each other as they terminate. The intake pipe works best with a 90 deg ell pointed down and the exhaust pipe typically works best with a 22 or 45 deg elbows on it pointed down. It is imperative that the holes and pipe penetrating house is sealed well. Now most important and partially mentioned earlier, there must not be any reducing couplings installed on horizontal runs, vertical only. Your changes in piping sizes are probably allowing condensate that is supposed to drain back to boiler, get trapped and is being expelled after it builds up via the exhaust ventor. Also just as important, the PVC piping (horizontal) must pitch back to boiler, 1/4" to ½" per foot. This again allows expelled condensate or condensate formed and condensed out of the exhaust fumes to be drained via the boiler drain system. (not outside) It is common for a bit of condensate to make it out and freeze under extreme conditions but, 99% of the time the longer run times or sun, knocks/melts it away. Perhaps the 3 pipe sizes were used because he replaced something larger? Or, thatÂs what he had on the truck? Good luck

Thank you, annz. After posting, I did a search on this forum for 'leaking windows' and found some info on wood hardeners and epoxy products. Also did a search on 'window flashing' when I realized that my window doesn't appear to have any (no caulk, either). I called the licensed contractor whose crew did the framing, windows, and exterior finish on the addition. He is supposed to stop by today to check the damage--at least I'll know what to ask about. We used the T111 because it was used on the house (probably installed in the early 1980s--we purchased the house in 1994), but I read in the link that not all T111 is the same quality. When the old siding was pulled off on that side, to add the new room, there was no problem with leaks or rot around the windows. One of the old windows wasn't affected by the new construction, and it's still OK. Thanks again for your help.

Mad_gallica: central Colorado All: The brick half wall goes into the brick about 8 inches at the points that are truly attached. It stretches across the left portion of the house where it becomes unattached again. At that point, It serves as a fence for the left 4 feet of the house in front of the dog run on the side. There is actually a real fence behind the brick wall there, so that's no concern if we were to decide to take it down. Attached are some additional pictures. The 3rd picture has an arrow showing where the wall is not attached again. To the comments about the downspouts we actually had gutter work done to correct gutters that were hung incorrectly. Out of 3 quotes, they all gave us two options either having the downspout where it was originally (running across the porch as you see in the first picture, which drove me mad) or moved along the side of the house in front of the wall as you see on my previous close ups. Running across the porch was awful and there was no way to paint it to disappear so I went with moving it. The middle pictures are old. The cedar is gone. The right cottonwood is also dead and removed (part of the reason for our working on the exterior).

Was your house inspected before the interior work proceeded? I have never heard of the interior being finished before siding. Our house had to pass a 'finished exterior inspection' before the electrical could be started. All siding materials (brick in our case), roofing, etc. had to be completed. Plumbing was allowed. Then our contractor waited through two rains to make sure there were no leaks before continuing with wiring, spray foam insulation, sheetrock, and then primer. Hardwood floors were put down after acclimating to the house and having the HVAC running for a couple of weeks. Trim work is ongoing at this time. We have one small section of metal roofing that has yet to be completed. It's located over a porch and was backordered.