Hole in the siding, and how to "fix"?

I've got Vinyl siding on my house, that I had to cut a 6" hole in to run the vent from my Keystoker 90 through... I'm wondering how you all managed to seal the hole around the wire mesh stuff best against the elements. Seems to me, rain or whatever could run down the side of the house and get behind the siding and onto the sheathing, etc without some sort of flashing ot J channel or something. What'd you come up with?

I used J channel around the SWG power venter I installed. Just slide it in around the opening and then seal it/glue it down with silicone. The sealing part is important, especially if the lower edge of vinyl is exposed.

mine came with a timble with a 6' pipe in the center. the flat part was 12" x 12". i through bolted the plates. the 4" flue goes through the center. chalked the top and the sides. put J-channel around it. flashing on the top probaly would of been a good idea. when i was finished i was getting fly ash on the siding. i put the chimney part 12" from the house. so i picked up a 6" pc of ss 316 and added it to the outside. so far so good. in the summer i will take the chimney and flue pipes down so there not in the way when i cut the grass and put a cap on it.

The vinyl siding is not considered water tight. It is a rain screen. It keeps the bulk of the water off of the house but siding must be installed over a water barrier like Tyvek or felt paper. All of your fixtures, windows and doors are flashed at this point. I would seal the pipe where it comes through the sheathing with a flexible flashing tape like is used around window openings or maybe a caulk type of sealant. If a fixture block could be found big enough that would be a nice finishing touch to run the pipe through, actually a meter block would probably be the right size. It is just a solid plastic block with an integral J channel that would give it a nice finished look. In short,think like a water drop when flashing, the water barrier is the membrane behind the siding, finish your siding in a way that diverts water from getting behind the siding but don't think water will not get behind the siding because it does. Vinyl siding has weep holes in it to let water out.

gaw is correct vinyl siding needs Tyvek behind it to protect the house structure. The bottom lip of siding has weep holes. A good siding installer will flash with metal leak prone areas as the siding is installed. For example below window sills, a piece of metal flashing is installed to divert water that makes it past the window frame seals to the weep holes on the siding row below the window. The metal flashing gets covered up by the next higher piece of siding.

If you go to the trouble of removing the siding around you vent you can so something similar. It has the advantage of having the caulking seal behind the siding and out of the weather so it will last longer.

Just another reason why I don't like "vine-nell" siding. The same thing happens with aluminum. On the parts of our house that still have aluminum siding water seeps out of siding where the horizontal panels meet after a heavy rain.