furnace exhaust vent in wall

[brian h]

I have upstairs bath that where we are adding a small 34x48 shower by stealing a small closet from the master bdrm. The concern is there is a oval exhaust(double wall b-vent) in the one side wall. that comes from the furnace downstairs. The vent meets code and there is 1/2" from the vent pipe face to the face of the stud.
The rough opening is 49" so I can do a few things but I'm concerned that products such a Schluter, or others may have issues with expansion/melting causing moisture/water failure due to the heat.

First thought was using layer of durock or add 1/2" wood to the face of the stud to create a 1" space. Even ceramic insulating wool in not out of the question, if necessary

Would anyone care to comment?
I'm not in a rush, there's a few months before this bath remodel

-Brian

[PC7060]

Hi Brian and welcome to the forum.

Not sure I understand the configuration, can you post a couple pictures?

[HooKooDoo Ku]

I don't know the details on building codes as it relates to furnace vents, but everything I can find online with a google search indicates that there is supposed to be a 1" minimum clearance between the vent and combustibles, and that a wooden stud is considered a combustible.

IMHO, create a 1" minimum clearance and it shouldn't mater what material you use (CBU, drywall, etc), heat shouldn't be an issue. Personally, the only thing I would be worried about would be IF you were using plastic as a waterproof material behind CBU. In that case, I would see prolonged exposure to the warmth of the vent causing the plastic to deteriorate over time. But if you create a 1" clearance with bare CBU facing the vent, I can't see where that would be a problem.

However, the best answer would be to consult with your local building inspector (there could always be local building codes that take a precedence over any build codes we might find online).

[brian h]

thanks for responding. Yes, it is normal for 1" clearance of combustible with heat exhauast vents, with an exception of a when a 4" b-vent is adapted into an oval to allow passing through a normal 2x4 stud wall. here is amerivents'
http://www.ameri-vent.com/type-b-ven...-pipe-fittings

can't do pics, digital cam is ? and cheap cell phone doesn't send to email/computer.

basically, one stud bay on the left side has a oval vent coming up thought the floor of the stud bay and passes though the top plate into the attic. There is no where else to run the vent(I wish)
My concern was products like Schluter would /could degrade being that close to the exhaust vent pipe.
Same with products like denshield, if possible to use but I find little info on this product is good/bad, even this site seems to have nothing when searching.

BTW, kitchen ceiling is below= deep poo is unit fails at later date.

Thanks again, brian.