Replacing a water heater in a very leaky, dusty closet. I thought I understand the need for a gap as so not to conduct heat to flammable material. So I used some high heat tape to seal it. Worked for a few weeks but it looks like condensation collected and detached the paint. Is there a better way?

The water stains were not there when I “improved” it. Think it’s a B type 4” but I know just enough to be dangerous. Double wall, original to the 1975 build judging by the old discolored paint spray.



Part of my work that fell away

You need a thimble to create the air gap and to seal to the ceiling or wall surfaces.

Thimble

Thanks. Definitely put me on the right trail. I’ve been searching lots of stuff with no luck.

What I’ve found so far is only for walls as thin as 3”. Duravent makes them but recommends some huge support box thing for ceilings. Maybe just due to certification.

Wish we had Menards around here. Bought a Honda generator from them a while back. Would like to get something fast so I’m trying local first.