# Bathroom vent through vinyl siding



## _alphaBeta_ (Aug 19, 2011)

Title says it all, and I'm looking for advise. I believe I'm good with making the hole with a hole saw and marking position, etc. I'm hung up on flashing the vent, however, and the type of vent to use. It needs to accept a 4" duct.

Most of the DIY I've seen involves caulking a standard wall vent to the existing siding, but I didn't think that was such a good idea in the case of vinyl siding given how much it shifts with temperature differences etc. Given the height of my panels, it also wouldn't be possible to mount a vent of this size to an entirely flat portion.

I found this, but I'm confused if I need to get underneath the siding to install the second half. Even still, I don't see how this will stop water from getting behind the siding. I must admit that, in general, J-channels on vinyl siding puzzle me as to how they manage to keep water out in other applications such as outdoor outlets and light fixtures (Anyone have a good reference? I'm missing the mechanics). Seems like the siding is wide open waiting for water to pour in.

Any help for finishing my bathroom vent project would be appreciated! Thanks.


----------



## joecaption (Nov 30, 2011)

Got the right part to do it just the wrong ideas on how it works.
The siding comes completly off in the area where the hole is going.
I then use a long 1/4 drill bit to go though the sheathing and the dry wall so the hole lines up.
Cut your hole with a 4-1/4" hole saw though the sheathing, stop and remove the plug, cut and push the insulation out of the way. Go on the inside wall and just use the 1/4 hole to guide the last hole.
If there's house wrap you can cut some slits in the corners so it can be folded back to cover the nailing fin. Nail the vent to the wall making sure it's level.
No house wrap then you can use window tape. (self sticking rubber tape)
Always cover the bottom the two sides then the top in that order.

Now you just have to cut the siding to fit around the siding block, always leave about 3/8" around the block. The siding needs to be able to slide back and forth as it get hot and cold. Last step is to just snap the trim piece on.

There is always moisture behind siding, that why there's suppost to be house wrap behind it. Just look at the bottom edges of any vinyl siding. There weep holes to allow the water to get out.


----------



## _alphaBeta_ (Aug 19, 2011)

The original item I linked to in the first post isn't available anymore (the item shown when following the link changed). The original item I was referring to is here. Looks like it's been discontinued.

Does anyone know where this can still be bought *or have other suggestions for a suitable vent through vinyl siding*?


----------



## wewantutopia (Feb 28, 2012)

I used these on our house: www.menards.com/main/doors-windows-...ryer-vent-mounting-block/p-1379359-c-5840.htm

It comes in 2 pieces making it's own j channel, pretty sweet!

It should be great for a retro fit.


----------

