Thimble for Wall Thicker Than 6"?

[Graham08]

Does anyone know of a source of a wall thimble for B-gas vent pipe for installations where the wall is greater than 6"? Or, would it be acceptable to roll an extension and rivet it to one side of the existing thimble?

I'm venting an Enerco low-intensity radiant tube heater horizontally through my exterior shop wall, which is 2 x 6 construction. I got a jumbo vinyl block so I would have a smooth surface to seal the thimble to (and a clean looking install), but it brings the overall thickness I'm trying to pass through to around 7-1/4".

I have a slip roll, so making the extension would be cake, just don't know if it's kosher to modify an existing thimble.

 

[dave67fd]

Your thimble should telescope enough to make up the 7 1/4".

 

[Charles (in GA)]

Most thimbles are, I think, good for an 8 inch block wall or similar. If it simply won't, as in the two pieces won't meet when you put them thru, and you have the capability to roll a tight fitting piece out of similar material, I'd go for it.

Charles

 

[Graham08]

I'll double check it. If it doesn't meet in the center, I'll get a piece of galvanized sheet and make what I need.

 

[NUTTSGT]

Maybe these will help you out, it's for Supervent products, it's a line that Menard's carries.


http://www.selkirkcorp.com/supervent/product.aspx?id=54
http://www.selkirkcorp.com/WorkArea/showcontent.aspx?id=1888

 

[Graham08]

Thanks for the link. Looking at that, the problem may be that I'm using 4" vent (same as the heater tube). The 4" thimble expands to 7", while the 5" expands to 8".

 

[ForceFed70]

Look into using a ceiling thimble instead. They are basically the same thing but ment for a wider gap.