"I thought the pic was out of context when the design dilemma was about tiling the backsplash behind the stove."

You can't just put tile on a wood framed wall with a stove with high BTUs without using the backguard/riser.

Some people are trying to advocate just using durock (with a fire rating), and leaving the wood studs.

Having a fire rating doesn't keep the heat from transferring to the building materials behind it.

The twin towers are the most notable example of how the heat, and not a direct flame can still effect the structure, even through the protective coverings on the structural surfaces.

Why would I bother bringing up examples that nobody has heard of?

I can't remember the last time I used jet fuel on the stove...

Hardibacker by James Hardie has a 1 hr fire rating. The product is non combustible but that doesn't mean heat wont transfer through. I have used this product behind every tile install for kitchen backsplashes over the past 30 years, residential and commercial. If this product had any problems with heat control over a cook top we would know. 1/2" thick is recommended for the backsplash so that it is the same thickness as your sheetrock.

Hardibacker applied directly over wood studs is NOT one of the approved methods of clearance reduction in TABLE G2409.2 (308.2).

http://publicecodes.cyberregs.com/icod/irc/2012/icod_irc_2012_24_sec007.htm

If you want to continue to do installations that don't meet the International Residential Code or ANSI standards, or even the installation instructions of the appliances, then you should probably be notifying your clients in writing of this negligence.

If the specs say one thing for safety purposes, then "well, we've done it this other way for years and we'd know if it didn't work" isn't that comforting because maybe you don't know about a failure? Or maybe the next house will be the first problem?

The issue the riser is addressing isn't the immediate wall surface catching on fire, it is heat being transferred PAST the immediate wall surface to the combustible materials behind it also, and those may catch fire without direct exposure to flame if they get hot enough. If you look at the risers, they are constructed so that there is effectively an insulating layer of trapped air between the burners and the combustible wall framing behind, quite possibly with some kind of heat sink effect also so that the trapped air never gets hot enough to transfer dangerous amounts of heat to the combustible surfaces.

Fire rating and heat transfer ratings are NOT testing the same properties. You can't use one where the other is called for and figure you are safely solving the problem, you just can't. You might get lucky and get way with it, but it is luck. And people who are unlucky with house fire issues end up dead.

(I think the scariest thing might be if enough heat transfers that the internal wall structure like the studs begins smoldering, but there ISN'T any visible flame or heat damage to the exterior wall. People go to bed after dinner, wall keeps smoldering, eventually produces smoke or something catches fire properly and people perish without having a chance to escape.)

This is an area where safety needs to come before looks, and maybe sales people are being misleading by not showing the riser or proper spacing, but as a consumer - suck it up and deal, or swap for a unit with different safety requirements so you can have the look you want. Don't do something fundamentally unsafe just because it looks prettier.

https://www.jameshardie.com/Product-Support/Resource-Center/Technical-Documents/Fire-Prevention-FAQ

The organizations that create the code could care less what james hardie says about their product. This particular part of the code is very specific to the ANSI standards and definitions which manufacturer's are required to meet and these standards are adopted for code. Fred is correct in what he is saying. The OP now understands that the original information provided to him is correct and the 10" riser is required. Beautiful tile can be put behind the riser, but cannot substitute for the riser.

"HardieBacker® 1/4" Cement Board is deemed noncombustible when tested to ASTM E 136 and can be used in conjunction with other NONCOMBUSTIBLE materials around a fireplace [or any other heat producing appliance]. This does NOT mean that clearances to combustible building materials can be reduced by using HardieBacker 1/4". Clearances to combustible building materials SHALL be obeyed even if they are protected by noncomustible materials."

@ Brickwood, actually, the link supplied by Cinar does agree with the codes and standards. It can't even be substituted for type x because it doesn't have the fire rating.

"Can you substitute JH products for gypsum to achieve a 1-hour rating?

Because heat will transfer through JH products, they cannot be substituted for Type X, fire-rated gypsum".

The heat transferring through the materials to the wood studs is the exact problem we are talking about and why it is against codes to do this.

I removed my riser at my last house because I was fairly confident I wouldn't have a fire due to my cooking habits. The only time I use the back burners is special occasions. Having said that, i realize if I did have a fire my insurance might balk at paying out. I went thru a house fire once, not from cooking, but a furnace, so I am pretty careful. I am currently remodeling and plan on using my riser, at least to begin with, as I haven't fully decided on my backsplash.

Recognize this?

"Fred S

Tile won't keep the combustibles behind it from burning any more than the stainless steel pan or ceramic crock keeps you from burning your food."

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Hardie tries to spin it by saying;

"Are your products 1-hour fire-rated?

While JamesHardie® products will not ignite when exposed to direct flame or contribute fuel to a fire, heat will transfer through them. Because of this, the product itself is not 1-hour fire rated. However, they do qualify for use in certain 1-hour fire rated Warnock Hersey and UL assemblies. Think of JH products as a pan used for cooking. The pan can be directly exposed to a stove's flame and not burn, yet the food in the pan will cook in time."

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Am I to believe that this means that a pan will keep the food from burning???

Or is Cinar just reading it wrong?

My front burners are 25,000 BTU and 22,000 BTU. My back burners are 18,000 and my simmer is 15,000.

There's just no way I'd chance it. Not worth it in the long run, and I barely even cook.

Fred I am well aware of the building codes. Never did I state anything about installing hardie flat against the wall or joists. It would be best if you would keep your ignorant remarks to yourself.

Cinar Interiors, Inc.

Yesterday at 7:14AM

Most tiles are fire glazed, they can withstand extreme amounts of heat without damaging. I agree about removing the plaster and lathe and to replace with 1/2" Hardie board.

"1/2" thick is recommended for the backsplash so that it is the same thickness as your sheetrock."

If it is the same thickness as the sheetrock, then it would be "installing hardie flat against the wall or joists."

If you are using 1/2" Hardie to fill in where the 1/2" sheetrock would go, then the Hardie would be just as tight to the combustible wood stud as the sheetrock.

Most approved clearance reduction systems require at least a 1" ventilated gap between the "shield" and the combustible material (wood stud). Hardie is not even rated to be such a shield by their own documentation.

Even with the proper (built on site) shielding, the allowed clearance reduction for Wolf or Thermador Rangetops would go from 12" away from the wall to 4"- 6" to the combustible wood stud within the wall, depending on the specific system. Not backed up tight to the wall like the pictures show. Blue star lists the clearance without the riser as only 6" to begin with, but any code compliant clearance reductions other than the listed riser would still require 2"-3" between the Rangetop and the wood wall studs, requiring the rangetop to be pulled away from the wall further than normal.

Considering that sheetrock is installed behind cooktops and it is secured to the joists, are you telling me that this method is incorrect? If so, than you have a valid case against 99% of all home builders in the US. If not, then how is it different when said sheet rock is replaced by hardie board?

"Considering that sheetrock is installed behind cooktops and it is secured to the joists, are you telling me that this method is incorrect?"

It is incorrect for the high powered gas appliances built by companies like Wolf, Thermador, and Bluestar if you are attempting to just use the "island trim" that comes with the unit up against a back wall. If you are installing these units against a back wall, the "riser" or "backguard" MUST be used.

This generally applies to all of their products called "Range"or Rangetop", but not to the products called "cooktops" since they are less BTUs.

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"then how is it different when said sheet rock is replaced by hardie board?"

Neither one meets the International Residential Code, ANSI standards, or the Installation Instructions of these high BTU appliances. In fact, as Hardie puts it, HardieBoard is NOT as effective as fire rated sheetrock for protecting the wood studs within the wall.

My housemate points out that purely from a materials point of view, a fire rating tells you nothing about how the material behaves when exposed to repeated heated and cooling cycles as you might see from a fire rated surface placed next to a high btu burner. Such repeated thermal stress may alter the actual performance of the fire rated product, unless repeated thermal stress is explicitly part of how the product in question is rated.

He also offers as an example fire rated safes - people have been sad to discover that a 'fire proof' safe did not protect a hard drive or floppy disk from damage in a fire. Why? Because the safe is rated such that in a fire of X duration it will keep PAPER from catching fire or becoming too damaged. That does not mean the temperature inside the safe will not get hot enough to damage other things. Same thing with a wall covering - unless designed for the job, it does not protect the wood studs and other potential combustible materials in the wall (wire insulation, etc.) from getting heated to a point of damage or, worse, to auto-ignition temperature, which is the temperature at which something gets hot enough to ignite without any external source of flame.

Where did it go? Oh, it just finally appeared up there ^^^

Must have been held up for the words "$Ück it" ;D

PirateFoxy said:

If the specs say one thing for safety purposes, then "well, we've done it this other way for years and we'd know if it didn't work" isn't that comfort...

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"or, worse, to auto-ignition temperature, which is the temperature at which something gets hot enough to ignite without any external source of flame."

+

"I have used this product behind every tile install for kitchen backsplashes over the past 30 years, "

=

Just about enough time to dry out those wood studs really well to where they ignite easier.

.

TIME, in this case, doesn't prove anything except that you are that much closer to a potential disaster.

"If you look at the risers, they are constructed so that there is effectively an insulating layer of trapped air between the burners and the combustible wall framing behind, quite possibly with some kind of heat sink effect also so that the trapped air never gets hot enough to transfer dangerous amounts of heat to the combustible surfaces."

The ones I have seen are not "trapped" air. They pretty much follow these rules.

c. Spacers and ties shall be of noncombustible material. No spacer or tie shall be used directly opposite an appliance or connector.

d. For all clearance reduction systems using a ventilated airspace, adequate provision for air circulation shall be provided as described [see Figures G2409.2(2) and G2409.2(3)].

e. There shall be at least 1 inch between clearance reduction systems and combustible walls and ceilings for reduction systems using ventilated airspace.

f. Where a wall protector is mounted on a single flat wall away from corners, it shall have a minimum 1-inch air gap. To provide air circulation, the bottom and top edges, or only the side and top edges, or all edges shall be left open.

So then all of these examples are against code? Unless I'm missing pages, I didn't see anything about a riser in my Dacor cooktop manual (yes, it will be against a tiled wall). Hard to find uses of a 6-10" riser-- I'm only finding all tile or a huge wall of steel.

Fred S - my housemate just commented he hadn't even considered the age of the wall materials as a factor, even though his cousin (a fire fighter) did warn us about keeping on top of things on this house as its 1930s and his experience with fires is that older wood framed houses, once they catch, do burn quite well because of the age of the wood. Greener/younger wood has more moisture and so doesn't burn as easily/quickly.

And I was being imprecise about the trapped air - what I meant was they aren't solid metal. They appear to have a layer of air inside the exterior metal surfaces that acts as insulation and helps transfer the heat away from the combustible materials. So I was thinking trapped as in 'cannot be blown away by a stray breeze, stays in place long enough for some heat transfer to the air to occur, so the heat is then removed when the air moves on.' Carefully controlled ventilation, essentially, I guess? The air doesn't move through too fast or too slow for purposes of reducing heat transfer to the wall behind. I imagine there is a lot of math and engineering involved in determining the right amount of airflow for the task.

And as far as photos - first, afaik there is no rule that photos on Houzz have to be up to code. Second, the code depends on the output of the burners. A commercial 'style' low power cooktop that doesn't put out a lot of btus may well have very different safety requirements than a high btu 'professional' range top. And many of the big names now make both the high btu units and also cheaper less powerful ones for people who want the name and bragging rights but not the cost or performance of the higher btus. (Some places, for example, you can actually have problems with the highest btu options due to the natural gas supply to or in your house not being adequate.)

In any event, photos existing does not actually change the laws of physics. There is heat generated. That heat will go somewhere. If it is not directed by an appropriately designed accessory for the range, the heat may well go into your wall, and with enough heat, your wall WILL catch fire - quite possibly without there being obvious exterior signs immediately, so you don't even realize.

Why risk it? Follow the safety instructions and deal with the aesthetics, or downgrade your cooktop to one that has requirements that meet your aesthetic preferences.

@ houselover22. If you read my posts above, you will see; " This generally applies to all of their products called "Range"or Rangetop", but not to the products called "cooktops" since they are less BTUs." TWO more times.

If you look at the Dacor "Rangetops", you will notice that they require a backguard if pushed all the way back to the wall.

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http://www.dacor.com/Products/Rangetop

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Dacor's appliances that they call "cooktops" probably don't need a backguard/riser, but you would have to give me the model number to say for sure. Most of their "cooktops" are sized so that when you cut the counter out to put the cooktop in, there is still about 3" behind it to the wall. The size of the "rangetops" are such that they need to be pushed all the way back to the wall, or they stick out way too far in front of the cabinets.

Now I'm worried!!! I have a marble slab behind my Wolf range, and it's installed against an exterior wall (my house is solid brick, built in 1890). I don't know what's between the exterior wall and what I see inside, but there's just a steel vented spacer thing running along the wall behind the range, level with the cooktop. Is that a fire hazard?

"but there's just a steel vented spacer thing running along the wall behind the range, level with the cooktop." - that sounds like an "Island Trim", not meant for use up against a combustible back wall.

Fred, thanks for the info. I apologize for not catching "cooktops" when you mentioned them before--I admit I blanked out a bit when all the talk of forum etiquette came up. I have Dacor DCT305s and the minimum in back is 3 1/4" so I'll be good to go with tile. Thanks for keeping an eye on codes!

Thank you, Frank. I suppose it's possible they used non-combustible studs behind the marble (the house was fully gutted about a decade before I bought it). I guess finding out would mean pulling out the range and opening up the wall?

I doubt it.

My plan is to rip the existing studs in the wall to remove 1.25" of material from them behind the range up 36". Put a 1/4" backer board and a 1" steel stud up. Then screw a 1/2" backer board over that to make the fire proof section flush to the rest of the wall and then tile over the entire wall. That is similar to a wall I demoed behind a wood burning stove once.

Hey Edison Guerra do you have pictures of what you did?

I'm also in the middle of a renovation and I'm trying to figure out the best way to do this.

Wow!! So happy to have seen this prior to ordering my FiveStar. I'll still order, but definitely changing backsplash area. I do have 2x6 studs and strawbale walls about 6' to the side of range wall. Not wild about the stainless backsplash, but I'll adjust. Great thanks to all !! You probably saved a lady that's been trying to build this house for over 30 years, from losing it in an easily avoidable tragedy.

As an update to earlier comments. The NC Department of Insurance (which regulates building codes in NC) has updated/clarified for our state that a wall where tile is applied behind a cooking unit is a non-combustible wall. Our local inspectors require that manufacturer installation instructions be onsite for inspections and we must meet the requirements. If tile is applied to the wall, then that would be the installation requirements that apply for a wall that is non-combustible. If no tile, then we must meet the requirements for combustible materials. That does not mean that safety should be ignored - particularly given the feedback all over the internet on issues where tile has been discolored and ruined by the heat buildup. Local jurisdictions can still interpret and administer regulations more strictly.

I'm sure that's news to the National Fire Protection Association.

Great thanks for the information!

Zak, here is a picture of what I did in my house.

Good thread besides all the bickering. I wonder if more jurisdictions have updated their code similar to what @Brickwood Builders, Inc.stated.

According to Thermador's Pro Harmony manual, a surface covered in tile is acceptable for the island trim with 0" clearance. Keyword, "covered":

"A rear clearance to a surface covered in a noncombustible material (metal, ceramic tile, brick, marble, or stone)* is 0" when using the included Island Trim."

Page 5 and screenshot below: https://media3.bsh-group.com/Documents/9001227768_A.pdf

if there's any remote chance of combustible materials behind the tile catching fire, it seems like a huge and unnecessary liability for Thermador to state this.

While it may not meet code in certain places (hence their disclaimer at the bottom), I don't think I'll worry about my plaster catching fire behind my tile.

I'm going with a 33" high by 3cm (1-3/16") granite backsplash behind our Wolf Rangetop. I am able to replace the 'Island Trim' with their 10" riser if desired as backsplash is BEHIND trim piece. However, what is the consensus on this being required? It will not look great but will do it if I need to. Located in So Cal by the way.

It's up to your local codes. If you're not taking out a permit just go by what the manual states is acceptable. As I wrote above, Thermador says you're fine to use the island trim as long as it backs onto the non-combustible granite.

Add a stainless steel panel to the wall above/behind your stove top. You could leave the tile you have so any tile beside that panel still shows .

"I don't think I'll worry about my plaster catching fire behind my tile.

HU:

It ain't gonna be your plaster, it's gonna be your wood studs that you've dried into kindling with the constant heating of the splash over the years. One day-poof!

This is what i did.

@Joseph Corlett, LLC I've monitored temps of the marble behind the island trim for this very reason, and the hottest it's ever gotten after 5+ hours of running the stove plus cooktop is 131.9 degrees, in just a small location. So no, I'm not worried about the plaster, or the wood behind.

Why would Thermador state that 0" clearance is acceptable if there's any remote chance of fire? Bosch's lawyers aren't that bad.

Thanks for the input. I'm a little concerned about a post Fred S made 5 years ago stating the non combustible surface needs to also extend downwards 6", (although the Wolf Product with air gap does not do this). I will continue to research and investigate thermal conductivity of granite etc. That will be once I finish looking in to make up air requirements for the 600cfm range hood!

@Andy Close I did 2 rows of tile down. Temps are higher above the range than this 6-8" below, at least when I tested. I was somewhat skeptical of all this too which is why I've taken a ton of temperature readings over the last year.

It sounds like your taking out a permit with the hood and MUA, so just have the contractor take care of figuring this out, or call the inspector over.

No permits, just trying to avoid any pains later on. I’m well underway with full tear out, planning on getting it right so your input is greatly appreciated. The house will be tightly sealed hence the make up air, plus it will help when using the fireplace.

I used steel studs, rockwool insulation and durock behind the marble tile I applied. When the oven is on the tile can heat up to about 270 degrees, so it was worth while for peace of mind. I got the final inspection and passed everything.

270!? What kind of range? Your marble is going to discolor at that temp.

It is a thermador pro grande. Fine so far after two years. I used a thermocouple so I may be getting some temp from the air. The heat is only from the oven. Thermador replaced the unit with a newer model and there is an air diverter so the temp will likely go down. While using the oven I would also use a tin foil diverter because the grease in the air is a pain and that would almost eliminate the heating.

I find these conversations to be interesting, enlightening and without personal application, as I ive in Florida where the majority of 'contracters' wouldn't know an ANSI code if it bit them, much less care. I wonder how the average homeowner can afford remodelling to code, when all the competent master electricians and plumbers, much less builders are only doing high end jobs.

"I live in Florida where the majority of 'contracters' wouldn't know an ANSI code if it bit them, much less care."

Please substantiate your argument.