Need advice: Snorkel install on vinyl siding

[CMM]

Hi All, I'm installing my first gas fireplace (LP) and using the direct vent option from the back of the stove. The instructions require a wall thimble and 'snorkel' on the exterior of the house to enable a minimum vertical rise for the exhaust gases. Our home has vinyl siding and I've seen some posts on this site for wall thimble installations on vinyl siding and either using J-channel or a lot of silicone sealant around the thimble, but I am struggling to know how to mount/install the snorkel. I can cut away the vinyl siding where the thimble will be, but if i cut away the siding under the snorkel it will be a significant amount of vinyl and this concerns me as well.

Does anyone have photos of a snorkel termination cap installation on vinyl siding to share that may help? Or any advice on whether I should mount everything directly onto the vinyl and silicone the heck out it...or cut some or all of the vinyl off and mount to the OSB, again with loads of silicone?

Thank you very much for your thoughts!
-Chris

 

[DAKSY]

Mount the snorkel to your sheathing, NOT your vinyl...Measure & layout the location for your wall thimble on the sheetrock inside & behind the fireplace..Drill thru to the outside. Lay out the dimensions of the snorkel centered from the pilot hole & add a minimum of 1/4" to the layout on all sides. Cut the siding to the oversize layout lines. Install the J-Channel. The top piece goes in first. Then the sides go BELOW the top piece. Then the bottom piece goes in between the side pieces. Fit them so the top overlaps the sides by the width of the J, & the sides extend that same amount past the bottom piece. Install the thimble. Now mount your snorkel, inside the J-Channel. Once you have the venting thru the thimble & secured to the snorkel, silicone the gaps between the J & the snorkel. The finished look will be more professional than mounting everything ON the vinyl.

 

[CMM]

Mount the snorkel to your sheathing, NOT your vinyl...Measure & layout the location for your wall thimble on the sheetrock inside & behind the fireplace..Drill thru to the outside. Lay out the dimensions of the snorkel centered from the pilot hole & add a minimum of 1/4" to the layout on all sides. Cut the siding to the oversize layout lines. Install the J-Channel. The top piece goes in first. Then the sides go BELOW the top piece. Then the bottom piece goes in between the side pieces. Fit them so the top overlaps the sides by the width of the J, & the sides extend that same amount past the bottom piece. Install the thimble. Now mount your snorkel, inside the J-Channel. Once you have the venting thru the thimble & secured to the snorkel, silicone the gaps between the J & the snorkel. The finished look will be more professional than mounting everything ON the vinyl.

Thanks Bob! I agree that this will look more professional. Will I need to use a standoff for the snorkel or will I be OK to mount directly onto the sheathing without a stand-off? The instructions say that a stand-off is not required for snorkel installation, however it also didn't say whether to install on the vinyl or not, and I dont have a good sense of how hot the snorkel will get when in use and if that will affect the adjacent vinyl.

Also, do you happen to have any photos of a snorkel installation as you described?

Thanks again,
Chris

 

[DAKSY]

I've never used a stand off with a snorkel cap. I don't recall ever seeing one.
Unfortunately, I have no photos. Maybe someone else here does.
You may have to wait nitl one of the other "gas geeks" checks in...

 

[xtrordinair]

when i install a snorkel with vinyl i remove the vinyl and i install 1x 4 concrete siding boards mounted to the sheathing .Mount the boards so that the snorkel mounts centered on the cement board .Put a bead of caulk around the edge of the cement board as well as the snorkel.then J channel around the boards and put siding back up.You can get the cement board in several colors or paint it .