DirectVent vent cap installation – Best?
Hi π
I am looking for advice on achieving a quality, attractive installation of a DirectVent stove vent cap through an exterior wall. I’m all set with how I’m going to handle the interior, room side of the stove pipe penetration. I’m concerned about making the exterior side look nice and avoid any problems with moisture intrusion. The exterior of the building is wooden clapboards. I am already set with how to conform to code about locating the vent, with respect to minimum clearances to hazards and dwelling openings.
Here’s a link to some diagrams of the components I’m using (this will open up in a separate web page):
http://umoc.stuaf.umass.edu/johnj/vent/
I’m trying to decide if I should install the vent cap and it’s accompanying, underlying wall thimble surface directly through the clapboards, or if I would be better off building a flat, square piece of finish wood into the clapboards first, maybe putting some trim molding around it, then making a hole through it for the vent. It would give me a flat surface to mount the vent to, and I could do some flashing over the top edge of the finish wood to direct water away from the area. Plus I thought it might look more finished than if the vent was just sticking out directly from the clapboards. Does anyone have any hints, tips or other thoughts I should be considering? Thanks very much for any of it! π
-John Jackson
Amherst, MA
Edited 10/14/2009 9:58 pm ET by JohnPJackson
Replies
John, your pictures didn't come through, but I know what you're talking about. I like to make up what's called a "light block" for anything installed on a wall, such as light fixtures, outlets, electric meters, and... direct vent thimbles.
Smaller light blocks are single boards, but for a thimble I would make it out of four pieces of wood. Kind of like a picture frame, but I would not miter the joints, just do butt joints. Use tar paper or Vycor behind the light block/siding joint, and top it off with cap flashing.
Would you use wood that was thicker than the depth of the clapboards? How much bigger than the footprint of the vent cap would you make it? Enough to create a border 2-3" wide, perhaps?The pictures on the link I posted are a separate web page. I didn't realize I could embed the pictures right into the forum posting here. I will try that sometime! :)