Flashing for around thimble

[Jakemedic]

Hello! I’m installing horizontal stainless steel vent in my post frame shop. I have the hole cut and was about to install the thimble. That’s where I froze. Shouldn’t there be flashing around the thimble? I don’t want to simply expect silicone caulking to keep the water out. It is a metal sided post frame building with a rib that had to be cut (of course i couldn’t land the thimble on the flat part of the wall). Thanks for any guidance this group can provide.

 

[penright]

I may be in the same boat, do you have any pictures?

 

[Bert_]

It's kinda hard with the sheet already on the wall.

I did a flashing for a roof penetration on my building. I ordered one sheet of steel 6" longer than the rest. That allowed me to cut the sheet at the pipe, use a normal metal flashing, and overlap the tin 6". That flashing will last the life of the roof with no maintenance.

 

[penright]

It's kinda hard with the sheet already on the wall.

I did a flashing for a roof penetration on my building.

I thinking about switching to a roof penetration. I was looking to do some DuPont FlexWrap EZ, and Dektite Red Silicone Metal Roof Pipe Flashing

I may have to go bigger on the pipe flashing, not because of the pipe, but the manufacture gave me specs for the ribs on the metal, and you have to have a bigger metal to hand it. Then if there is an issue, the guy who built the building said he would sell me a cut off so I can do what you did.

I was just curious if anyone did it horizontally and how did they flash around the thimble.


Here are a couple of videos that I watched that gave me the idea.

FlexWrap video

Boot install video

 

[Jakemedic]

Hello! Not perfect, but I believe it to be water tight. Ended up slicing the steel horizontally at the top and bottom and sliding in j channel and adding silicone. Now to finish the inside and slide my stainless steel pipe in. Never dealt with anything quite like this before (then again it is my first metal building). The original opening wasn’t quite big enough and I wanted to protect from water getting in. The next trick is the hole is 4.25 inches and the pipe is 4 inches. The manufacturer states to use high temp silicone around the pipe. Maybe a trick. Was thinking of centering in the opening and suspending it in the center, put my silicone in and allow it to set up........ does anyone else have better plan? Thanks!

 

[TractorJeff]

Hello! Not perfect, but I believe it to be water tight. Ended up slicing the steel horizontally at the top and bottom and sliding in j channel and adding silicone. Now to finish the inside and slide my stainless steel pipe in. Never dealt with anything quite like this before (then again it is my first metal building). The original opening wasn’t quite big enough and I wanted to protect from water getting in. The next trick is the hole is 4.25 inches and the pipe is 4 inches. The manufacturer states to use high temp silicone around the pipe. Maybe a trick. Was thinking of centering in the opening and suspending it in the center, put my silicone in and allow it to set up........ does anyone else have better plan? Thanks!

I rested mine on the bottom, thinking over time the pipe will settle tearing the Silicone seal

 

[Jakemedic]

I rested mine on the bottom, thinking over time the pipe will settle tearing the Silicone seal

I was wondering about that as well. Going to try getting it in today. Thanks!

 

[WisJim]

When I had a wood stove in a shop/garage many years ago, I used a Metalbestos brand thimble and their matching flashings to go through the wall to the masonry chimney. I would think that their would still be similar products available.

 

[Jakemedic]

Ended up using hi temp silicone around outside and inside. Worked remarkably well. Just need to finish up the gas line and I will be ready to go. Will work better and more efficient than my mini split.