View Full Version : There is a P trap in my water heater vent pipe
PC211
Jan 12, 2009, 07:47 PM
Hi everyone,
In my new house, I just discovered the flue pipe looks like a P trap. I am guessing it was installed by a hack of all trades.
Anyway, I want to route it correctly. The path I would like to take is straight up through an interior wall. This wall is framed with 2x8s so there is some room to work with.
Can anyone give me some advice as to what size/type of connections/adapters/pipe to run?
-From the top of the water heater to the shingles is about 12'.
-Things I would have to penetrate: subfloor, bottom plate, top plate, roof sheathing, shingles.
-It is a 40 Gal standard water heater.
-Interior wall, no insulation.
Thanks!
Milo Dolezal
Jan 12, 2009, 10:15 PM
You will use 3", type "B", double wall, gas vent. You will have to install fire stops where vent penetrates bottom and upper plates. If you have 12' of straight vertical run then use three 4' sections of vent. Lock each piece together and secure with 3 sheet-metal screws where pipe slides into each other. If you have to make turns, use double wall, type "B" , adjustable 45 degree ells. Stay away from 90 degree turns. Use spacers to keep vertical run from touching interior wall covering. Maintain at least 1" clearance from combustible materials. If you have to go through drywall, use "bucket assembly" to penetrate drywall. Install roof flashing, pipe collar, vent cap. Push upper part of flashing under layer of roofing shingle. Seal under the flashing and along side the outside edges with Henry 208 sealant.
PC211
Jan 13, 2009, 11:33 AM
You will use 3", type "B", double wall, gas vent. You will have to install fire stops where vent penetrates bottom and upper plates. If you have 12' of straight vertical run then use three 4' sections of vent. Lock each piece together and secure with 3 sheet-metal screws where pipe slides into each other. If you have to make turns, use double wall, type "B" , adjustable 45 degree ells. Stay away from 90 degree turns. Use spacers to keep vertical run from touching interior wall covering. Maintain at least 1" clearance from combustible materials. If you have to go through drywall, use "bucket assembly" to penetrate drywall. Install roof flashing, pipe collar, vent cap. Push upper part of flashing under layer of roofing shingle. Seal under the flashing and along side the outside edges with Henry 208 sealant.
Milo,
Thanks for the information. One more question, is there a minimum distance the top of the water heater has to be from the ceiling? Right now it is sitting on the concrete floor in the garage. If I elevate it 18" the top will be fairly close to the ceiling. The garage is only about 6' tall.