Re: condensation ring on window
calcats' assessment makes some sense. You should be able to check this yourself: put a piece of masking tape on the outside, then go inside and see how far it is between the inner and outer surfaces.
When the weather warms up, the gas will expand and the gap will widen, so you'll want to check it out on a cold day.
Besides, on second look, the pattern is too large for my suction cup theory. Phooey.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.