Randy, I agree with Jeff's statement. You are faced with a dilemma: You could check with Woodstock to see if they will give you a credit for the the two elbows and and "ridge cap" which mounts on the slope of the roof. They would sell you the additional chimney needed to complete that part of the "straight up" installation. If they agree, you would have to start planning for the installation through the ridge of the roof. You would then follow the details I provided in my original post either doing the work yourself or hiring someone who is somewhat familiar with framing and roofing. I would strongly urge you NOT TO USE one of the available adjustable ridge caps because they are difficult to make weather proof and don't look that good (my opinion).
If you are going straight up through the ridge of the roof, building a chimney chase with custom cap is the most waterproof and most attractive way to proceed. It has been years since I did a web search for the construction details of a ridge mounted chimney chase. However, I do recall seeing some very helpful drawings of the details and they were free to download.
Most sheet metal shops are very familiar with manufacturing chase caps so once you give them the length and width dimensions of the chase they will know how much (usually about 3") it should overlap the sides of the chase. The chase cap will have a slight bent-in slope so water flows off. The cap will also have about a 1/2" drip edge built in to the bottom edge of each of the overlapping pieces. The hole where the chimney goes through the cap should be about 1/8" larger than the OUTSIDE dimension of your chimney.
The sheet metal shop will also drill a 3/16" mounting hole on each side of the chase cap. You might have to tell them where you want the hole drilled so the mounting screw will be set in 2"x 4" material instead of the 5/8" or 3/4" sheathing on the chase.
I would also recommend that one of the screws used to secure the chase cap be a short, threaded eye bolt screwed all the way in so the base of the "eye" is up against the chase cap. This eye bolt can be used to temporarily mount a bucket for holding tools and other supplies when working around the chimney.
Here is what I did to weatherproof the storm collar on the chimney: Once the cap is in place, squeeze a good (1/2") bead of high temp silicone caulk (I use the red colored kind so it is easy for the inspector to see from the ground) around the chimney about 1" above the chase cap. Then mount the storm collar so its seam is on the leeward side of the chimney and slide it down into the silicone caulk. You want some of the caulk to ooze into the seam between he storm collar and chase cap. Place another 1/2" bead of silicone caulk on top of the storm collar and lightly smooth it with a wet finger (be careful not to cut your finger). Using this process will provide a weatherproof bead of silicone above and below the storm collar where the chimney goes through the chase cap. However, always follow your manufacturer's recommendations if they differ from mine.
All these details can seem overwhelming if you have never done this kind of work. However, to one who has built a chimney chase even once, the process becomes a "piece of cake".
I would recommend you print some of the details Jeff and I have provided so you can quickly refer back to them in the event you choose to run the chimney through the ridge of your roof.
Good luck with whatever you decide to do. ;-) John_M
If you are going straight up through the ridge of the roof, building a chimney chase with custom cap is the most waterproof and most attractive way to proceed. It has been years since I did a web search for the construction details of a ridge mounted chimney chase. However, I do recall seeing some very helpful drawings of the details and they were free to download.
Most sheet metal shops are very familiar with manufacturing chase caps so once you give them the length and width dimensions of the chase they will know how much (usually about 3") it should overlap the sides of the chase. The chase cap will have a slight bent-in slope so water flows off. The cap will also have about a 1/2" drip edge built in to the bottom edge of each of the overlapping pieces. The hole where the chimney goes through the cap should be about 1/8" larger than the OUTSIDE dimension of your chimney.
The sheet metal shop will also drill a 3/16" mounting hole on each side of the chase cap. You might have to tell them where you want the hole drilled so the mounting screw will be set in 2"x 4" material instead of the 5/8" or 3/4" sheathing on the chase.
I would also recommend that one of the screws used to secure the chase cap be a short, threaded eye bolt screwed all the way in so the base of the "eye" is up against the chase cap. This eye bolt can be used to temporarily mount a bucket for holding tools and other supplies when working around the chimney.
Here is what I did to weatherproof the storm collar on the chimney: Once the cap is in place, squeeze a good (1/2") bead of high temp silicone caulk (I use the red colored kind so it is easy for the inspector to see from the ground) around the chimney about 1" above the chase cap. Then mount the storm collar so its seam is on the leeward side of the chimney and slide it down into the silicone caulk. You want some of the caulk to ooze into the seam between he storm collar and chase cap. Place another 1/2" bead of silicone caulk on top of the storm collar and lightly smooth it with a wet finger (be careful not to cut your finger). Using this process will provide a weatherproof bead of silicone above and below the storm collar where the chimney goes through the chase cap. However, always follow your manufacturer's recommendations if they differ from mine.
All these details can seem overwhelming if you have never done this kind of work. However, to one who has built a chimney chase even once, the process becomes a "piece of cake".
I would recommend you print some of the details Jeff and I have provided so you can quickly refer back to them in the event you choose to run the chimney through the ridge of your roof.
Good luck with whatever you decide to do. ;-) John_M
