A: Dear EL, Precipitation of any kind does not effect the Chimney Balloon, but sunshine is not good for the balloon.
The UV in sunshine will break-down the rubber retaining ring on the interior of the Chimney Balloon. That is the reason we use viton retention rings if you are going to use a Chimney Balloon in a skylight chute to stop cold air from coming in around a skylight.
If you get a significant amount of precipitation in your chimney you may want to seriously consider a cap. The freezing and thawing of moisture in a chimney can cause problems with the tuck pointing and the bricks.
Q: Jason, Since I don't live between the Tropics of Cancer and Capricorn, I don't
have to worry about the sun ever being directly overhead. So, UV from
the sun is not a concern.
I don't believe I have excessive precipitation as I live in New England in the US. But I do get some. I'm purchasing a house with many fireplaces. The heat is off this winter and I have noticed some small amounts of snow have accumulated in a couple of the fireplaces. So, my concern was about having this accumulation sitting on top of an inflated chimney balloon and eventually melting.- EL
A: I understand EL, Snow or rain will just sit on the top of the Chimney Balloon until it evaporates. It will not effect the material of the Chimney Balloon at all. - Jason