I think I would follow the manual instructions on that. Unless of course the person at Viking CS is will to put that advice in writing. And from what I know, adding tile alone will NOT make a wall considered non combustible. Get the backguard.

A non combustible wall is a brick or block wall, with no wood. Covering a combustible wood wall with something non combustible just transfers the heat to the interior. Which is bad news, as it creates pyrolysis. That lowers the ignition point of the wood even further, making a fire ever more possible.

Buy the back guard. That’s what it was designed for. The island trim is what it’s called, for islands (a stupid spot for a high heat output stove …)

How I wish the manufacturers and showrooms would stop showing island trims on wall installations.

$430 later I’ve got an ugly back guard getting shipped next week. Very deceiving practices by these manufacturers/marketers

I agree!

It IS very deceiving! Or lazy of them. I dunno. I feel it’s also the fault of many designers as well. Our last house had a Viking range and we didn’t have the back guard... because we didn’t know better. We did at least have concrete backer board because we had a huge wall full of tile... but we just didn’t know. This house I have a bluestar, and while we knew better this time, the sales people had NO clue. We didn’t go with the wall being non combustible, but we did go with the back guard. I’ve gotten used to the look.

The problem is that I’m 99% sure absolutely nothing would happen. Even my local building inspector said I was fine with just tile on drywall. He said if I wanted to go overboard i could durock behind it. When we read the manual together he ultimately agreed that because the manual stated combustible WALL and not combustible SURFACE, that I should probably buy the backguard, but he would not fail me if I just used the tile. He said that’s how 99% of them are installed that he sees and it ultimately falls on the homeowner to follow the manufacturers guidelines because the code doesn’t get that granular.

I’m a worrier, so i decided the $430 plus sacrificing the looks was a small price to pay to not have to worry every time I use my stove for extended periods of time that I’m gonna burn my house down. Or future owners, etc.

I believe that when UL approves an appliance, it does so under the condition that the installation and usage directions are followed. Otherwise, nominally safe equipment might well become hazardous to operate. If directions are found by an insurance company to not have been followed, then it is possible that they could claim that damage from a fire was partly the fault of the owner.

Often in a renovation or new construction, if the need for a non-combustible wall is known in advance, then the wall structure requirement can be met at minimal additional cost. It seems that the only way the homeowner can achieve this is to read all installation guides before any construction is performed.

Given the comments of the AHJ in this case, one could build and get approved a "pretty" backguard so long as the essential elements described in IMC 308.4.2 were understood and incorporated. Basically, an air gap scheme is needed with cool air dilution. One could build up to the hood, and install tile on the face. Whatever added gap was needed w.r.t. the range itself could be obscured by using a deeper counter.

Now since I’m purchasing and installing the bank guard I plan to keep the drywall in place and tile on top of it rather than rip it out and install durock. Because I’m using the bank guard it’s now strictly cosmetic and I could hang wallpaper there if I really wanted to. Am I interpreting that correctly? Counters go in Tuesday so I’d want to change the drywall before then if I still need to.

Also, the area below the cooktop surface behind the oven is fine to just have tile continue down a few a inches and then be bare drywall, right?

If the back guard is considered the only requirement for use with a combustible wall structure, then in principle wall paper would be OK. Something easier to clean grease off of might be recommended. Also, while the back guard is needed to protect the wall from normal usage degradation, one needs to imagine the consequences of an unplanned flambé.

I highly commend you for ordering the back guard, even though it messed up the “look” of your kitchen design! Better safe then sorry, right?

I can only assume that the manufacturer’s lawyers added that specific 6” non combustible clearance in the manual for a reason.

Maybe they had a few costly lawsuit settlements with non-disclosure agreements???

Yes, @kaseki I’m definitely not putting wallpaper, i was just making a point that I can pick whatever I want now and but rebuild any aspect of the existing wall before installing tile.

@rebunky thanks. I am a better safe than sorry person when it comes to things that could cause fire/flooding…it’ll help me sleep better! My wife and I decided that at the end of the day a beautiful Viking range with an 8” backguard is still a beautiful Viking range. We’ll embrace it and try to make it look purposeful.

This is illogical. The metal back guard will transfer heat into the combustible wall much more efficiently than covering the same drywall surface with porcelain tile. Cancel the metal sheet and tile the wall as you plan to without it. Nothing is going to combust. I only wish you had put as much research into your range choice.

Dan: OP's OP says 3/4-inch clearance with back guard.

Dan - with the backguard I can have 3/4” clearance. Without I need 6”. I’m going to tile the wall regardless. How is this illogical?

I did a backguard....I don't mind how it looks at all. It's supposed to look like a commercial range. Here's my hubby grilling a steak for me. :-)

Plain & Fancy Kitchen - Dayton Ohio · More Info

" He said that’s how 99% of them are installed that he sees and it ultimately falls on the homeowner to follow the manufacturers guidelines because the code doesn’t get that granular."

Local codes often make the manufacturer's installation instructions the local code standard.

"This is illogical. The metal back guard will transfer heat into the combustible wall much more efficiently than covering the same drywall surface with porcelain tile. Cancel the metal sheet and tile the wall as you plan to without it. Nothing is going to combust."

Dan, you don't know of what you speak. The back guard can create an "air wash" chimney type cooling effect between the back of the guard and the front of the combustible wall unlike tile.

"Potential for pyrolysis

Pyrolysis is defined as the chemical decomposition of wood or coal by the application of heat alone in the absence of oxygen. In short, it is the repeated heating of wood resulting in its changed chemistry and ignition temperature. Typically, this process happens over a long period of time and includes many cycles of heating and cooling at temperatures as low as 200°F." https://www.greenbuildingadvisor.com/article/202479

You are correct that "Nothing is going to combust", but you forget to add the "right away" qualifier at the end of your statement.

I am in a similar predicament. We are remodeling and I was planning to remove the 18” high shelf attached to my Viking in order to tone down the commercial style a bit. I was unaware I would have to replace it with a back guard and I’m not too pleased. Seems like it’s commonly installed without. We just added a full (quartzite) backsplash. Where did you purchase? Thanks.

relyfe:

The laws of physics do not care how pleased you are.

I purchased directly from Viking because I could not find it used or from a 3rd party. If your stove its older you may have luck finding it used but there are a few different part numbers depending on your range.