hearth ext construction/hearth temp survey

[szmaine]

Hiya-
This is kind of two topics in one-

1. I'm in the process of making a hearth extension for installation of Oslo F500 into an existing fireplace.
I've read through every post I can find about hearth pads/ extensions/ micore/ durarock etc...
Well you can lead a horse to water and all that...
So far I've got the extension part made of recycled tin ceiling panels (low profile design) cemented to 1/2" Hardibaker w/ latex mod thin set - the plan is to extend over the remainder of the brick hearth using a thiner board to compensate for the slightly raised brick hearth (proud of the floor by 1/4"). It looks really cool if I do say so.
I'm not worried about the brick hearth as it is 4-5 layers thick, but am having misgivings about the extension over the maple flooring. The front of the stove will be about 5 inches from the beginning of the extension. Am I nuts to go with it? The dealer had assured me that all I needed was non-combustable protection. But its not attached yet, I can still fix it. Thoughts??

2. Survey - Has any one out there gone around measuring the temperature of their hearth material at various locations?
What temp did you get? what is the hearth material? how far from what part of stove (ie under, in front ,sides).

 

[firefighterjake]

As I've said in the past I firmly believe in more protection vs. less . . . that said, the Oslo manual and Jotul (confirmed through the dealer) says only that ember protection is needed for floor protection. As for me I felt better going with two layers of 1/2 inch Durock (which is listed as floor protection) and then using slate tile for the "look" . . . and of course I installed the bottom heat shield. For me it just made sense since I tend to over-build when it comes to safety and it would be really, really embarassing for a guy who preaches about fire safety to have a fire in his house so I went over-board . . . plus I figured if I ever replace the stove with another that requires a certain R value I may either get lucky and meet the requirement or at least have a base for increasing the R value.

I would check with your local Fire Inspector and/or Insurance Agent . . . the Inspector here in Bangor for example requires listed floor protection . . . even if the manual only says ember protection . . . again his belief is better safe than sorry . . . an ounce of prevention . . . etc. Some Inspectors would simply follow the manufacturer's requirements.

And yes . . . I have measured my temps of the hearth at various locations . . . honestly with the heat shield in place the temps are relatively mild . . . no triple digit temps . . . I can't remember the exact readings, but nothing extreme . . . heck, my cats love lying on the hearth right in front of the stove where it does tend to get warmer than the floor on the sides. The bottom heat shield makes a big difference.

 

[szmaine]

Thanks for the quick reply. BTW, I'm actually in Winterport so we're neighbors.

I'll go ahead with what I'm doing but you convinced me about adding on the bottom heat shield -
When I ordered the stove (Evergreen, Ellsworth) I wondered if they were really effective and cheaped out at the time, but since all of it will qualify for the tax credit it'd be dumb not to get it.
This set up is really supposed to be temporary anyway - what I really want to do is take up part of the floor extend the hearth w/
cement board and re-tile over the whole thing, including the face of the fp, but don't have time right now.

Another ? - mantle shield...
seems like the prefabs are 24g steel and Ive seen a post where someone made one out of 14g steel...
does the gauge really matter, what will happen if it's too thin?
I've got this tin ceiling theme - thought I might use a length of cornice to make a mantle shield, but that is usually 0.010 steel.
Will it buckle or what?

Should I be starting a new thread every time I have a random thought - I have lots of them..

 

[firefighterjake]

Yup . . . a fellow Waldo-County-ite . . . although we're pretty much on opposite ends of the County. Closer to my workplace though . . . in fact just a few weeks ago I was down your way teaching a CPR class to some dental assistants/hygenists.

In any case, I thought the bottom heat shield came with the stove and just needs to be added . . . the rear heat shield is an option however . . . or at least that's the way it was. In either case, I installed both for the peace of mind.

Evergreen in Ellsworth -- top notch folks . . . they really know their stuff. I was sad to see the owners pull out of Bangor . . . and as you may or may not be aware when they left the stove shop they were running here in the Big City the new owners had some "issues" -- apparently having a salesman selling folks stoves at rock bottom prices, but not delivering them isn't good for business. That shop is now gone . . . as I said, I was sad to see the folks at Evergreen leave since they ran the stove shop very well and seemed to be on top of things. Evergreen also helped out the FD by volunteering to come in at last year's Open House and staff an informational booth for folks who were curious about pellet stoves and woodstoves as last year there was obviously a lot of interest in heating with wood and pellets.

I like your long-term idea . . . but completely understand about the time issues. I've got three or four proverbial irons in the fire and a whole lot of projects that I haven't even begun to start yet . . . right now I'm just kind of juggling the various projects, working on each a little at a time.

I'm not sure about the mantle shield question . . . if you don't get an answer here in a day or so I would post a separate thread with the question in the thread's topic as that might get some answers . . . and the one good thing is that folks here are wicked smart and love to help folks with their questions.

 

[firefighterjake]

Listed floor protection per NFPA 211.

 

[szmaine]

I was googling around to see about the bottom heat sheild since you mentioned that your's came with it - apparently that is a thing of the past and it it listed as an accessory everywhere I looked - it'll cost another $97 or so.

Anyway, as I was nosing I found a link to what looks like an older version of the Oslo manual at Northwest Stoves website - looks different and has a notation at the end of March 2000.4 (not sure what .4 means, possible version 4) - it gives a Minimum R-value for alcoves as 1.6 as does the current version of the manual at the Jotul website - but also gives a minium of 0.5 for all other installations.
I wonder why they changed it - it would seem prudent to have some minimum recommendation - especially since a bottom heat sheild apparently used to be standard equipment???

Yeah, I rememer the whole Sunrise Hearth snafu. The CREEP! I never did hear if people were ever got their stoves or at least their $ back.

 

[firefighterjake]

I was googling around to see about the bottom heat sheild since you mentioned that your's came with it - apparently that is a thing of the past and it it listed as an accessory everywhere I looked - it'll cost another $97 or so.

Anyway, as I was nosing I found a link to what looks like an older version of the Oslo manual at Northwest Stoves website - looks different and has a notation at the end of March 2000.4 (not sure what .4 means, possible version 4) - it gives a Minimum R-value for alcoves as 1.6 as does the current version of the manual at the Jotul website - but also gives a minium of 0.5 for all other installations.
I wonder why they changed it - it would seem prudent to have some minimum recommendation - especially since a bottom heat sheild apparently used to be standard equipment???

Yeah, I rememer the whole Sunrise Hearth snafu. The CREEP! I never did hear if people were ever got their stoves or at least their $ back.

No kidding . . . now the bottom heat shield is an option . . . guess it makes sense from a financial stand point . . . why give something away for free when you can get some folks to buy it. That's too bad. I do like the heat shields -- they do a good job.

As far as the R value minimum? Hard telling . . . as I said I purposely built my hearth better than just having ember protection since I wanted some R value . . . regardless of what Jotul stated was necessary . . . a minimum requirement is just that -- the minimum . . . I like building in extra safety.

 

[szmaine]

Ordered the bottom heat sheild and got the scoop on the whole R-value thing...

Dealer says; people were leaving the ash pan door open to start the fire (I have read here that sometimes it just didn't shut properly)
causing the stove to overfire and crack the floor of the stove. Jotul had to replace these. So they changed/improved the floor construction and it met the testing requirements (sans heat sheild) of floor temp not exceeding - what did he say, 217F I think - the point at which all moisture is driven from the wood enabling
combustion- if a stove meets this requirement then they don't have to have R-values for the hearth materials.
They also added a note on the inside of the door that if you use the ash door to start the fire the warrenty is void.

I'll sleep better with the sheild.


BTW - Evergreen is opening a store in Brewer in a couple weeks.

Oops- Its 212F, but I guess someone new that.