DIY Home Improvement Forum banner

Single wall to B-vent?

1 reading
4.9K views 3 replies 4 participants last post by  REP  
#1 ·
Hi, I'm venting a water heater. Its in a basement, goes up a wall cavity, then through the attic. I want to use single wall form the WH to the wall cavity, b-vent in the wall and in the attic

My question is: Can this be done? Or does it need to be double-walled the whole way? Do I need a special connector from single wall to b-vent?

The main reason I want to do this is that the span from the WH to the wall cavity is a little convoluted, and its really easy to cut a single-wall to length.

Thanks for any replies.
 
#2 ·
Well...
The code for this is a little complicated. First of all, the clearance for B-vent to combustibles is 1", which means no wood or drywall (or anything combustible) within 1" of the B-vent.
How much single-wall vent you can use depends on the following:
- the height and diameter of the b-vent chimney
- the btuh of the water heater
Could you draw a picture, label the sizes and lengths, take a picture, and post it?
I'm sure someone on here has a code book handy. Mine is at work, so I won't be able to respond until tomorrow.
 
#4 ·
Single wall pipe that is crimped will fit into B vent.To vent in a wall you will need oval B vent.That is what it is designed for.
If its a cold basement you will want B vent from the hot water heater all the way to promote proper venting.
Ask where you buy the vent material ghow to cut B vent.Its not that hard.