Plugging a skylight chute

Q: Jason, I understand the application of a Chimney Balloon is to plug a Chimney flue but is it possible to plug a skylight chute with a Chimney Balloon?

I have this skylight on my roof that leaks in cold air like crazy. When you stand under the skylight in the winter you can actually feel the cold air fall on you, so I can imagine the heat I am loosing is significant.

I have looked high and low for a plug for this skylight chute since I really need to plug it, but I don’t want to remove it. Can I get a Chimney Balloon made that will fit this application? I drew a diagram of the chute (see images) – TR

A: Dear TR, This is a bit unorthodox use of a Chimney Balloon, but yes you can use it to plug a skylight chute. The membrane of a Chimney Balloon will degrade a little more rapidly with the exposure to the UV rays, but if you wanted to diminish that impact you could put a UV film on the skylight before installing the Chimney Balloon. Also, we will make the interior retainer ring out of Viton since our regular rubber retainers will also degrade with exposure to UV.

A custom 22×49 would be the right size according to your diagrams. Go a few inches oversized in length since the chute wall slopes out – Jason