Painted Durock (or hardibacker) for Heat Shield

[begreen]

It's raw, and to be quite honest, doesn't look that terrible considering it's in a rustic cabin. The stove is in an out of the way area, and certainly not the center of attention. I mentioned having some paint that I could use on it (high heat like you mentioned) and that comment evoked a bunch of belly laughter.

It was a bit step for them to accept the need for the heat shield in the first place.

LOL, Real men don't do heat shields? I can hear the comments now. Are you going to trim the edges with a nice fringe?

 

[pen]

LOL, Real men don't do heat shields? I can hear the comments now. Are you going to trim the edges with a nice fringe?

Spot on. Tough crowd, but great guys. Fringe? haha, no!

I'm just happy it's much safer now.

The cabin is "paneled" with pine boards that were put up green right on the studs. Which means there is now a 1/2 inch air gap between each of them (including the ceiling). The room used to be cathedral style, but now has what can only be described as a pine board "drop ceiling", except with gaps between each board.

With so much circulation around the boards that make up the walls and ceiling, if anything ever took off in that room, I don't think it'd take 90 seconds to be fully engulfed.

For 25 years, there has been nothing but a single asbestos like (or actual) board that looks like brick measuring 30inches by 36 inches to protect the wall from the bottom barrel of the stove (obviously not even covering that completely). Then, 8 - 10 inches above that, another identical board for the top barrel. This stove was about 15 inches from this pine wall. Those asbestos boards were screwed directly to the pine, no air space. The durorock went with 1.25 inch air space against the wall to protect it from the bottom barrel, I re-purposed the old fake brick asbestos panels on their side to form a continuous heat shield right up the wall.

Finally this year they decided that the old stove had seen enough service, and had a new one built. I was asked to come out and help remove the old one and install this one. After putting in the new stove, light got behind the stove next to their small panels and it was evident that the pine around their small wall shields was scorched.

I spoke with the son of the owner and told him I was going to go out and put up a wall shield, with or without his consent. He told his father, the two went and for the first time saw the scorched wood, and then became quite agreeable to the wall shield.

It had been there for so long, with no problems, they simply thought it was safe and just honestly never gave it another thought.

Considering drunks (myself included in that elite category of individual) sleep within spitting distance of that stove several times per year, I'm really happy it's done.

Thanks again for the help guys, as always.

pen

 

[BillT]

That makes no sense to me at all... There is no way you're gonna ignite this cement board especially at 125 degrees!

Ray

It didn't sound right to me either, so I was questioning him about it. The answer he gave me was "It's starts to break-down after 125". In my opinion, I took that as them only calling that number, the number to what they would stand up to.

Other than that, I'm just repeating what the guy told me. As mentioned, it was the guy at the USG Headquarters in Chicago, Ill, phone number (312) 606-4000. He was the guy that I got transfered to when I was asking about the Micore. It might have been the Tech guy, but since I was just asking about Micore availablity, I didn't pay extra attention to that.

There is always that chance that he could be wrong, but we should probably ask USG for those specific specs in writing.

Bill

 

[pen]

You can find them online yourself with a search, or just follow the USG link I gave earlier.

A board called permabase, which has actual beads of styrofoam in it that are visible, cannot be used over 220 degrees.

The guy just flat out was wrong, either he misquoted something by accident, or what happened, who knows, but his info is incorrect.

pen

 

[BillT]

That is not correct. Next Gen durock is fine for heat shields. Cement boards such as PermaBase are not ok.

Here's the literature on it (broken link removed)

Here's the cliff notes version:

The board is non-combustible and can be used in a variety of fire-rated designs. Its low thermaland hygrometric expansion help prevent finish cracking.

DUROCK cement board Next Gen includes a wind load rating of 30 PSF and is UL Classified for fire performance. It offers a 30-year transferable warranty for interior applications and a 10-year transferable warranty for exterior applications.

pen

It's nice to see all the good things written about it, as I have always liked the product and have confidence in it.

But, it doesn't state anything in a Fire Rating or Resistance in the form of Degrees. As mentioned in my post above, we should try to get that info from them in writing.

Bill

 

[pen]

Here's another USG link (broken link removed to http://www.usg.com/rc/system-catalogs/durock-cement-board-system-guide-en-SA932.pdf)

pen

 

[pen]

It's nice to see all the good things written about it, as I have always liked the product and have confidence in it.

But, it doesn't state anything in a Fire Rating or Resistance in the form of Degrees. As mentioned in my post above, we should try to get that info from them in writing.

Bill

I don't think you are going to find it because it's listed as 0 for combustibility. It just doesn't burn.

 

[BillT]

You can find them online yourself with a search, or just follow the USG link I gave earlier.

A board called permabase, which has actual beads of styrofoam in it that are visible, cannot be used over 220 degrees.

The guy just flat out was wrong, either he misquoted something by accident, or what happened, who knows, but his info is incorrect.

pen

Pen, you were responding to mine at the same time that I was responding to your earlier post, lol.

I agree that he could be wrong. When I was talking to him, just to make sure I verifed with him that we were talking about the new type of Durock. I now hope that he wasn't wrong about the .39 R-Value. But, in my opinion, it is all enough to pursue it and get the specs in writing from them.

I will actually call again myself, but it would probably be better to have someone with some authority from this board to request the ratings in writing, or get them to add it to their link provided. Even if he is wrong, it would nice to have whatever specs they actually are, listed.

Bill

 

[bag of hammers]

It had been there for so long, with no problems, they simply thought it was safe and just honestly never gave it another thought.

Considering drunks (myself included in that elite category of individual) sleep within spitting distance of that stove several times per year, I'm really happy it's done.

Thanks again for the help guys, as always.

pen

Wow you just brought back a lot of memories - fuzzy weekends spent in some pretty interesting old shacks on some of the backcountry lakes up here in the middle of nowhere. Amazing we're still alive. Lots of fun though.

 

[pen]

Pen, you were responding to mine at the same time that I was responding to your earlier post, lol.

I agree that he could be wrong. When I was talking to him, just to make sure I verifed with him that we were talking about the new type of Durock. I now hope that he wasn't wrong about the .39 R-Value. But, in my opinion, it is all enough to pursue it and get the specs in writing from them.

I will actually call again myself, but it would probably be better to have someone with some authority from this board to request the ratings in writing, or get them to add it to their link provided. Even if he is wrong, it would nice to have whatever specs they actually are, listed.

Bill

This document supports the .39 r-value if you scroll down a few pages.

(broken link removed to http://www.usg.com/rc/data-submittal-sheets/panels/durock/durock-cement-board-submittal-CB399.pdf)

pen

 

[pen]

They list durock passes the ASTM 136E combustibility test, which is why they don't give you the number.

From what I can find, this test is with a furnace set to 750 or 1382 (broken link removed to http://gigacrete.com/wp-content/uploads/2012/10/GigaCrete-3116593SAT-004-PlasterMax-ASTM-E136-report1.pdf)

It looks as though I'd have to pay cash for the actual ASTM 136E explanations document. The link above is the closest thing I can find to specifics about the test w/out handing over cash.

ETA: Here's another link to support the 750 temp associated with this test. http://www.ngctestingservices.com/fire.html

pen

 

[BillT]

This document supports the .39 r-value if you scroll down a few pages.

(broken link removed to http://www.usg.com/rc/data-submittal-sheets/panels/durock/durock-cement-board-submittal-CB399.pdf)

pen

Pen,

Appreciate the link, as I have not seen that one before. I also noticed the .39 R-Value on it, which I was glad to see.

As mentioned, just to make things clear and rule out any doubts, I will be calling back. Only this time, either way, I will be getting the name of the person that I talked to. It is something that I usually get, but as mentioned, the main purpose of my call was for Micore.

Bill

 

[raybonz]

Bottom line is the Durock NexGen is better than the original Durock. I used 2 layers on my hearth and it worked great..Greatly improved R-value and easier to work with.. Knock on wood my hearth has held up fine so far..

Ray

 

[DMbekus]

Came across a dangerous situation a buddy has that needs a heat shield on a dime.

Wondering if anyone is using straight durock (or hardibacker) with the 1 inch spacers for air space behind it, that is simply painted for a side heat shield.

If so, how's it holding up?

Was standard or high heat paint used?

Also, how brittle is durock? I've only ever worked with hardibacker before. Wondering if it would be better to use hardibacker instead of durock for a standalone situation like this. Where it's located it should not be abused once up, just never worked with the stuff to know how brittle it is compared to the hardi

Thanks for the help

pen

I used hardiboard, only about 3 weeks though,no paint yet. Easy to install, smooth for paint and cheap.
From thier specs;
"Non-Combustibility

HardieBacker® cement board is recognized for use in non-combustible construction in NER-405.
Basic Composition/Size

90% Portland cement and ground sand. HardieBacker® board contains no asbestos, glass mesh, formaldehyde, or gypsum
Thermal Resistance

(Approximate value) 1/4'' thick: R:0.13"

 

[bag of hammers]

A board called permabase, which has actual beads of styrofoam in it that are visible, cannot be used over 220 degrees.

I noticed that when I used the permabase product in a shower install (a great tile backer). This is a good point,, and a great thread IMHO - I've noticed people often seem to just refer to everything (permabase, durock, hardiboard, etc.) as "cement board", but they all have different properties, applications,etc.

 

[begreen]

Spot on. Tough crowd, but great guys. Fringe? haha, no!

I spoke with the son of the owner and told him I was going to go out and put up a wall shield, with or without his consent. He told his father, the two went and for the first time saw the scorched wood, and then became quite agreeable to the wall shield.

It had been there for so long, with no problems, they simply thought it was safe and just honestly never gave it another thought.

Problems with this kind of installation often only occur once. There are lots of burnt up cabins in the woods. I'm real glad to hear that no one became a statistic here.

 

[firefighterjake]

. . .
It had been there for so long, with no problems, they simply thought it was safe and just honestly never gave it another thought.. . .

pen

Sadly we see this a lot . . . folks assume that since something has been in place for years without issue that it is safe . . . until that "one time."


Well done Pen!

 

[BillT]

Pen,

Appreciate the link, as I have not seen that one before. I also noticed the .39 R-Value on it, which I was glad to see.

As mentioned, just to make things clear and rule out any doubts, I will be calling back. Only this time, either way, I will be getting the name of the person that I talked to. It is something that I usually get, but as mentioned, the main purpose of my call was for Micore.

Bill

Well guys, I finally got a chance to call back. I talked to a nice guy in the Techincal Dept at USG in Chicago. It was a different guy this time than the other day, which I was glad to get. He echoed every single thing that the first guy stated. Sorry to say, but that included that the New Generation Durock Panels are only good to 125 Degrees, according to them.

I also asked him what the old Durock was good to and he did not have that handy. He said that he would have to research and I didn't ask him to do that at this time, but I am curious to what they say we lost from the old panel to the new panel.

Although I did ask him why they quit making the old panel if it was such a better product for heat protection. His answer was that they found the new panel to be better and being lighter he told me that "Light is in".

I also asked if they having any plans making the old panel again and the answer was no.

I also got his name this time and a direct dial number to the Tech Dept if anyone would like to call to re-verify what I have been told. Just contact me for that info.

Bill

 

[raybonz]

Well guys, I finally got a chance to call back. I talked to a nice guy in the Techincal Dept at USG in Chicago. It was a different guy this time than the other day, which I was glad to get. He echoed every single thing that the first guy stated. Sorry to say, but that included that the New Generation Durock Panels are only good to 125 Degrees, according to them.

I also asked him what the old Durock was good to and he did not have that handy. He said that he would have to research and I didn't ask him to do that at this time, but I am curious to what they say we lost from the old panel to the new panel.

Although I did ask him why they quit making the old panel if it was such a better product for heat protection. His answer was that they found the new panel to be better and being lighter he told me that "Light is in".

I also asked if they having any plans making the old panel again and the answer was no.

I also got his name this time and a direct dial number to the Tech Dept if anyone would like to call to re-verify what I have been told. Just contact me for that info.

Bill

This still makes no sense to me at all.. Taken from Durock NexGen below..

 

[ScotO]

Sorry to say, but that included that the New Generation Durock Panels are only good to 125 Degrees, according to them.

I, like Raybonz, find it hard to believe that the Durock NexGen panels are only good to 125 degrees........maybe he meant celcius? And you have the Permacore, which has a chitload of styrofoam balls in it and clearly states in the data sheet it is NOT a non-combustible board, and they claim it's good to 220 degrees? Something isn't kosher here........

 

[pen]

Bill, thanks for calling. Did you ask why his information is in conflict with all of the NextGen Durock info that's available online?

 

[pen]

I, like Raybonz, find it hard to believe that the Durock NexGen panels are only good to 125 degrees........maybe he meant celcius? And you have the Permacore, which has a chitload of styrofoam balls in it and clearly states in the data sheet it is NOT a non-combustible board, and they claim it's good to 220 degrees? Something isn't kosher here........

My thoughts exactly. Very puzzling

 

[bag of hammers]

I also asked if they having any plans making the old panel again and the answer was no.

That's really disappointing. The durock board is great for many projects. I used durock (and some metal studs) to frame in the front of an old hunting shack stove - using it for an outside feed sauna.

 

[BillT]

I agree, but I encourage you all to call too. Actually would like to see someone else call so you can talk to them directly and ask some of the questions that could be better qualified than I could ask. USG Corp phone number is 312-606-4000 and their direct dial number to the Technical Department is 800-874-4968.

Keep us posted.

Bill

 

[BillT]

Did you ask why his information is in conflict with all of the NextGen Durock info that's available online?

I more or less shyed away from that as I believe that the online info does not quote an actual number in Degrees as they so on the phone.

Another reason why I would like to see someone else call that is more knowledgable than I am to "confront" them on it.

Bill