Be sure that the flue has time to warm up before you burn extremely hot fires. During the combustion process, vaporized creosote floats up and out of the chimney. If the pipe is cool up at the top, even if only in the beginning, the creosote vapors will cool and harden and a combination of downdraft and the chimney cap can cause it to condense on the area you have indicated. Try warming up the flue system by burning a little newspaper- this will efficiently warm up the flue and hopefully prevent your problem!

Snow and rain very rarely falls straight down the chimney, which may be the reason why not having a cap has not affected you personally. Also, air flow patterns as the wind blows across the roof of the house, through surrounding trees, and over nearby hills can cause air to blow precipitation. Unless you begin experiencing weather issues with the chimney, the wire mesh should be sufficient at keeping out debris and critters. However, be sure to have the whole chimney inspected regularly as creosote buildup can occur in the openings of the mesh causing drafting problems and gasses to build up in the flue system.

I really need your help…!!! We have a cap on our chimney that is operated from the fireplace by a chain that’s attached to the top of the cap. I wasn’t able to have a fire going when this snowfall of the century dumped two feet of snow on us. Now I can’t get the cap to open in order for us to make a fire. It’s a spring loaded dealy. I have had a space heater going up the chimney for a couple of days, if anything’s melted, you can’t tell. I also thought about having the neighor kids throw footballs at the snow piled up on that stainless steel cover. How in the world am I going to get that snow off there sooner than later? Any bright ideas? Should I try starting a small fire and yanking on the wire?

Thanks for your quick response, the second storm is here and I hate wasting a prefectly good snowy day/night w/out a crackling fire!

Teddy