Quick check on my roof vent flashing

[Andy_GTS]

Just checking to see if I'm doing this right. Where should I put the sealant? Should I nail on the exposed part of the flashing and cover the heads with sealant? Should I tuck under the last layer of shingles? I'm a total noob at this.

 

[RivennHewn]

Personally, I like to leave a little bigger reveal around the boot. If you're to tight, you'll get build up of pine needles and such. Leave it clear of any mastic. It's there to give the water someplace to go. Keep any mastic under the shingles.

Other than that, it looks pretty good.

 

[Andy_GTS]

Personally, I like to leave a little bigger reveal around the boot. If you're to tight, you'll get build up of pine needles and such. Leave it clear of any mastic. It's there to give the water someplace to go. Keep any mastic under the shingles.

Other than that, it looks pretty good.

Thanks for the reply!

So no nails through the flashing flange? Only mastic under the flange and under the shingles above the lashing?

 

[The Cobbler]

nice job. I second the "leave more gap at the shingles" but I doubt it will ever be an issue if you just leave it as is.
seal the underside of the shingles( and any shingles you loosened up to install the flashing) to the flashing with caulk. 4 nails along the bottom edge of the flashing to keep it laying flat and not becoming a flap in the wind. seal the nail heads
when you install the pipe & storm collar, put some silicone around the pipe & flashing, push on your storm collar and silicone that edge to the bvent pipe too.

 

[RivennHewn]

Any nails should be hidden/under a shingle.

 

[Highbeam]

Do not use any goop anywhere. Your reveal around the base of the cone is slightly tight, but not bad. I like a healthy half inch or a finger width.

The nails that hold the flashing should be located up under the shingles. I like four as far apart as practical but obviously far away from shingle edges or **** joints.

No goop.

Oh and the hole in the roof deck is supposed to be the same size as the base of the cone since it has the built in 2" clearance to the stove pipe.

 

[Andy_GTS]

Do not use any goop anywhere. Your reveal around the base of the cone is slightly tight, but not bad. I like a healthy half inch or a finger width.

The nails that hold the flashing should be located up under the shingles. I like four as far apart as practical but obviously far away from shingle edges or **** joints.

No goop.

Oh and the hole in the roof deck is supposed to be the same size as the base of the cone since it has the built in 2" clearance to the stove pipe.

I used roof cement under the shingles. Too late now I guess.

As for the hole, I cut a 6-6.5 inch hole. My vent is 4in and the furnace instructions said 1 inch to combustibles.

 

[Andy_GTS]

Here is the almost finished project. My question now is what caulk should I use on the storm collar? The same red high-temp RTV I used on the draft hood connector or just regular clear silicone?

 

[D45]

I just used clear 100% silicon.....the best outdoor rated caulk I could find, I think mine said 30 year warranty

I slid the collar up, put a THICK bead down, slid the collar back down and then put another THICK bead on the top of the collar

 

[D45]

as for the hole, I cut a 6-6.5 inch hole. My vent is 4in and the furnace instructions said 1 inch to combustibles.

This is perfect, a 6" hole is fine for a 4" vent

 

[D45]

No nails along the bottom of the exposed flashing?

I used a thick bead of neoprene roofing caulk under my vent flashing and used 3-4 nails to hold the flashing down tight against the shingles, so that wind and temps can't lift the exposed portion up

Then smeared some roofing caulk over all the nail heads

Been dry for 4 months

 

[The Cobbler]

either of the silicones will be fine. I would put a bead around the pipe & flashing, then install the storm collar and another bead around that. slicked down with a finger wipe

 

[ForceFed70]

Nails on the bottom of the flashing depend on the area. An area subjected to high winds should get a couple of nails on the bottom covered by some sealant.

If you're in an area not prone to high winds, you can rely on sealant underneath to "glue" the flap down.

Overall - looks like a great job OP!

 

[SuitorsGarage]

No exposed fasteners ever on a roof unless it is unavoidable. High quality asphalt based sealant between the flashing and roofing if you live in an area with snow.

 

[Andy_GTS]

Well we had some 40-50mph winds this past week and no signs of lifting. I think the roofing cement is holding well. I won't be nailing the bottom for that reason.