Butyl tape or caulk?

[daveinaz]

Sorry for all these questions. I hope that soon I'll be able to be giving some answers.

I need to reseal the outside frames of both furnace and water heater where they attach to outside wall. Do you guys recommend butyl tape, caulk, or what?

I'm asking because there was NOTHING around the water heater! Just metal to metal and metal to fiberglass. The frame was directly contacting the outer wall and nothing between it and the face of the water heater.

So now I'm figuring "as long as I'm at it," I may as well go over the entire rig and redo seals and stuff.

I've read some threads that recommend against silicone because you have to remove all of the old to add new so I'm just asking what's best. Not looking for cheapest since I figure that it's cheaper to use good stuff and only do it once instead of using less quality and having to redo it.

Thanks again.

[MARK A]

Personally I would do both.. Install the butyl tape and wait a few days for it to stop squeezing out. Trim off what has squeezed out and seal over with a high quality clear sealer. That will assure a seal, and also keep the butyl from turning black and ugly.

Mark

[rohrmann]

On our rig, the water heater is caulked with silicone, and the heater is not caulked. You need to be able to access the heater by removing the cover, so don’t caulk that.