I need to patch several holes in the garage ceiling for a customer, among which is above the water heater. I can easily drywall it to repair it, but I’m wondering if I need to do some metal flashing around it per code?? Or is the cylinder part where it meets the ceiling already heat proof?

If I need something more than drywall repair, what can I use from the big box stores?

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You need a bucket around the double wall pipe coming through the ceiling...

[www.ameri-vent.com]

and it looks like the existing double wall vent pipe is installed backwards.....joints could leak carbon monoxide gas into the house etc...kill people, pets etc...

I would not touch it it unless they correct the vent pipe.

The "B" vent IS installed correctly, and you just need a "thimble" that slides over the pipe against the ceiling to seal the opening.

that looks like single wall going into some B-vent.

That is the male end of the vent pipe sticking down. If it was the female end you wound see a gap for the male end to mate up with it. No gap.

It is installed wrong.

Of course it is. That is how it is done.

Those are the tabs on the female end that engage the male end. It is correct.

It looks wrong to me.

[store.acpro.com]

Curly, the expanded view of the pipe shows the horizontal slots that are distorted inwards to grip the male end(if it was installed). It looks like a bushing was inserted and the bottom edge of the DW bent in to help retain it.

Alright...I give, you guys win.

How do you get a expanded view ?

Thanks for setting me straight....you to HJ.

With these photos, you click on the photo to enlarge it.

the B-vent is installed right side up.
I always put 3 sheet metal screws to secure the smoke pipe to the B-vent
it needs 1 inch air space around it to keep it away from combustibles.
a 2 piece thimble is the factory recommended fitting.

So what do I do? Do I need to take out the flue to put a collar in on or do they have something I can attach? Or metal flashing I can contour just for the ceiling where the drywall is broken?

the code worries about combustible surfaces.

if there is any strapping or framing above the sheetrock close to the pipe it must be removed.

the thimble is really designed for a penetration thru combustibles. you are just going thru sheetrock so it seems to me that the thimble is overkill.

we do worry about covering ourselves in case anything happens down the road.

if you feel comfortable, just use a smoke pipe storm collar
I probably would use one.
smear some fireproof caulking around the pipe to seal it.
orange store carries these.

Thanks, Packy! I'll look for it at Big Orange when I go today.

It's for a customer. They just had the garage drywalled and are worried about the little holes and gaps in the ceiling...they have a mice problem. Not sure mice would be interested in going up a hot flue though. LOL. But the customer's always right when they want to pay me for my services.

Look again. The "groove" you referring to is the space between the single wal and the outside of the "B" vent. It IS correct.

You just need an Amerivent 3EVC collar to slide up over the "B" vent after you pull the single wall out and then put it back in afterwards.