caulking/sealing stove pipe fittings

Apply high temp metal or silicone tape to the joints on the outside of the pipe. If you apply it internally you will never get that pipe apart again. If you are using the pipe that twist together you shouldn't use screws, you risk puncturing the inner pipe and it's not necessary. No need to move the rope gasket. Assemble and tape up the seams and done.

I used duravent after talking to several installers. Most recommended to seal both inside and outside joints with high heat RTV. I was wondering about taking the pipes apart sometime in the future for cleaning so I put 2 pieces together with RTV and tried to take them apart a few days later. By hand with gloves on it was not going to budge so I used 2 strap wrenches and they turned apart easily. I also used the strap wrenches to assemble the pipes, made it much easier. I bought the wrenches at Harborfreight for about 10 bucks for 2. They have rubber straps and grip the pipes nicely. I also sealed the adapter that went on the stove with RTV and used a hose clamp to tighten it down. There are 4 joints inside my house and all are leak free and tight. When the stove is operating, there is not even a whiff of smoke smell in the house.

At the stove exhaust to pipe junction I would use hi temp silicone caulking, run a bead around the inside and outside to form a good seal. I personally like the tape for all other joints, it's easily removable should you need to do so in the future.

I went straight out only about 2 feet with an angled piece down with a grate on the end to keep critters out. However on the outside my exhaust is 4 feet above the ground so I could do it.

joed2323 said:

With my stove the exhaust vent is horizontal so I originally thought the best way to vent would be straight out 12" then to a elbow and straight vertical 3-6' ending with termination cap.

Would their be any benefit if I went with 90 elbow off the stove going vertical 3-6' then another 90 elbow and outside with termination cap??

Click to expand...

Cleaning issue with 90 at stove. Would-should be a cleanout tee.

T at the end of the horizontal with a cap on the bottom part of the T. Open the cap an run a brush straight down from the top to clean.

Personally I use RTV (high temp silicone) on inner pipe EXCEPT those that will need to come apart for cleaning (not all do). On those that need to be disassembled silicone tape on outer joint works great. With regular Duravent, I have had to RTV even the outer joints of their factory seals on 45's and 90's.

For vertical rise, taller is better in terms of developing natural draft, so it's a matter of clearances and cost. Personally I have a 4' rise after horizontal and it works well.

Will help keep your siding cleaner. Negative, its a pain to brush out the venting and do a leaf blower treatment. I know what wind is as we live on the southeast side of the Red River Valley.

I use the rtv on inside joints that don't need to come apart to clean. Therefore, I don't have any rtv on the appliance adaptor or my last connection before going through the wall. I see no reason to rtv outside joints. Do not screw the duravent pipe, it will destroy it.

ForPellet stove venting:

"Pellet stoves have to push the exhaust air through the vent pipe with the stove's exhaust fan. With less restriction your pellet stove will breathe easier and burn more efficiently. First let's clarify the word restriction. Restrictions come from several different items.

1. 45 degree elbows

2. 90 degree elbows

3. Horizontal distance

4. Vertical distance

5. Elevation where you live.

A rule of thumb equation we are using has been adopted by most pellet manufactures. The equation is called the sum of Equivalent Vertical Length (EVL). All of the above mentioned venting restrictions have been assignedEVL values as follows:

1. Each 45 degree elbow = 3 EVL

2. Each 90 degree elbow and Tees with cleanout = 5 EVL

3. Each foot of horizontal run = 1 EVL

4. Each foot of Vertical run = 0.5 EVL

5. Elevations above 3000 ft with an EVL of 7 must adapt to 4 inch vent pipe.

If your installation is below 3000ft, we would need to do some math. The rule of thumb equations is that if the sum of the EVL is 15 or greater, then the pellet vent pipe would be increased to 4 inch diameter pellet vent pipe." http://nevelsstoves.com/pellet-stove-venting.html