Maybe a new thread just for mantel clearances-yes.

[RedRanger]

Just finished reading the other thread on hearth and mantle clearances. Just now looking at my manual for my PE insert (1985) and it shows mantle and/or top facing 20". Of course because of the date it also shows 16" clearance for hearth in front of door.Well, we all know that is now 18 inches. I know that when burning for an extensive time with nice hot fires the bottom of my mantle is hot,I can keep my hand on it but still don`t like it feeling that hot. I`m wondering if the clearance today might not be 24", because that is what it is with the new PE D1 Pacific, similiar size to my insert. In checking I note that I can lift the top mantle off,and am wondering if maybe I should raise it another 4 inches? That wood on the underside of my mantle is bone dry. Or some other solution besides that ugly (heat shield).?

 

[mshute]

I was faced with a mantle clearance issue when shopping for a new wood stove to sit on my hearth, also was not interested in the heat shield and neither was my wife! I had started to look into stone mantle pieces but didn't find much help on-line although, I've seen some pics from different members on here with stone mantel shelves that look great, check your local stone dealer, they may have some scraps leftover that could be used. Otherwise, I would think the old manual would still be valid if nothing on the insert has changed.

 

[RedRanger]

I just went downstairs and measured and I do have 24 inch clearance. Still don`t know just how warm that underside is really supposed to feel? So, even though it would be up to today`s code, still think I`m going to raise it or something.

 

[Metal]

I don't know if it is necessary to make the change, but I can tell you it won't make the situation less safe, so if it makes you sleep better at night change it.

Most of the time codes are not backwards enforcible, so as long as you meet the current codes at the time of installation you are fine, i.e. if you have an old smoke dragon, you don't HAVE to replace it with an EPA stove, but it would probably still be a good idea. If something is found to be truly unsafe, the manufacturer would probably have to do a recall (like accidentally misprinting a clearance of 18" as 8" in their manual).

 

[OZME]

Interesting stuff. I recently purchased a Jotul Catine F 400. The manual calls for 16" hearth in front of the door, my Towns Code inforcement says to install as per manufacturers directions if it is a "listed" stove which Jotul is, otherwise follow NFPAs standards.
Back to the mantle issue, My jotual manual recommends 23" clearance to the mantle for a F 400. My stove is in an existing fireplace. The glass door is even with the front of the fire place but the ash lip and top edge of the stove stick out into the room(the top by about 1"). My mantle is not 23" above the top of the stove that sticks out (more like 20") ... I guess I am probably not in code. I will find out soon as I am getting the stove inspected by the town, so I will see what they say.

 

[webbie]

As metal says, code updates are not RECALLS. It is not like Aluminum wire where the made you change everything or rip it out. UL sits around and says "Well, the existing 16" is safe and we understand that is fine for 98% of installations, but let's go to 18" because we want to cover 99% instead".

In other words, if the stove meets the labeled and tested requirements as per when it was built, you can assume safety.

As far as "how hot", anything over 120 is going to feel very hot to your hand. Anything over 130 you would not be able to hold your hand on. You have 40-50 degrees above that before you fail the UL test, and probably 2 to 3x that (270-400 degrees) before even long term exposure would turn it to charcoal.

The actual ignition point of certain combustibles is an often debated point, which is why they keep the standard WELL below even the most conservative estimate. You can find literature, but no proof, that combustion is possible in some way or another (eventually) at 250 degrees. Personally, I doubt that! They cannot make it happen in a forestry lab or at UL, etc.

But, as mentioned earlier, building materials have finishes and cannot warp or dry out too much.......I think these get affected before even the UL top line. So, in my view, too hot to touch (130-140) is too hot for combustibles.

 

[webbie]

As other have mentioned before, one theory involves that wood heated to lower temps (200+) for long periods of time - breaks down and eventually becomes "self heating" increasing it's own temperature to one at which it can ignite. Note that they are not saying it ignites at lower temps - just that it eventually heats itself up with some internal reaction (again, difficult to make happen in a lab), and then ignites at the typical temps of 400+ degrees F.

see:
http://virtual.vtt.fi/virtual/innofirewood/stateoftheart/database/burning/burning.html
http://www.fpl.fs.fed.us/documnts/fplr/fplr1464.pdf

Bottom line is that 170 degrees is the accepted temperature by virtually all the scientists....because no one can EITHER prove or disprove the other temps. The original BS all started when fires were reported from the field with steam boilers, which should not get above 212 F. But they do - if the controls malfunction, a pipe close to the boiler could get extremely hot when and if the steam (water) level in the boiler dropped.

That is why the lab work was never able to set a standard - because the reports of low temp combustion are mostly from firemen in the field (investigators), who obviously were never able to measure the temps involved (only guess).

 

[RedRanger]

Thanks for the infor Craig: Okay,I`m going to leave the mantle the way it is. Unless one of these evenings I find that I can`t hold my hand on the underside of it. Then that will be definitive.

 

[begreen]

Interesting stuff. I recently purchased a Jotul Catine F 400. The manual calls for 16" hearth in front of the door, my Towns Code inforcement says to install as per manufacturers directions if it is a "listed" stove which Jotul is, otherwise follow NFPAs standards.
Back to the mantle issue, My jotual manual recommends 23" clearance to the mantle for a F 400. My stove is in an existing fireplace. The glass door is even with the front of the fire place but the ash lip and top edge of the stove stick out into the room(the top by about 1"). My mantle is not 23" above the top of the stove that sticks out (more like 20") ... I guess I am probably not in code. I will find out soon as I am getting the stove inspected by the town, so I will see what they say.

In your specific case, I would guess that the lintel of the fireplace is acting as the heat shield. Just my opinion, but I don't think you will have a heat problem with the mantel. Do keep an eye and a hand on it to check.

 

[FPX Dude]

I too was concerned about clearances when I installed a FPX ZC 36. Previoulsly I had a "tract-home" Superior brand fireplace box that was ~ 18" top of fireplace to the mantel. Yes, I would get the dang thing going hot, and the underside of the mantel was hot to the touch, yikes So, I would put a little 9"fan on the ground and aim the air-flow at the mantle to help alleviate this and also circulate the air in the room. I ripped out that junk and put in the FPX. Clearance from top of fireplace to mantle is now less at ~12", and clearance to 2" recessed sides is ~ 6". Yes, I understand your concerns for clearances, but my installer said everything would be fine. The FPX blower ventilates via the top of the fireplace and I'm happy to say that surface temp underneath my mantle is basically "wall-temp" like the rest of the room. Hey, I'm in Sacramento and it's 40 degrees, yet I'm 73 degrees inside, yip-eee

 

[OZME]

Thanks BeGreen. Thats what I figured, I held my hand on it last night when the Stove was cooking along at 600 and it was warm but could defiently hold my hand on it. You are right in the 90% of the stove top is blocked by the lintel, I was a little worried about the 1" sticking out but I think it is ok.

BTW LOVE the Castine so far! Burns great! Am using 12 year old Black Locust that burns almost as good as the Redgum I grew up with in Australia.

 

[rsiros]

Admin posted a great non-intrusive way to use a mantle shield in my original post- mount under lintel. I think I'm going to try making one this weekend.

 

[begreen]

Thanks BeGreen. Thats what I figured, I held my hand on it last night when the Stove was cooking along at 600 and it was warm but could defiently hold my hand on it. You are right in the 90% of the stove top is blocked by the lintel, I was a little worried about the 1" sticking out but I think it is ok.

BTW LOVE the Castine so far! Burns great! Am using 12 year old Black Locust that burns almost as good as the Redgum I grew up with in Australia.

If you can hold your hand on it after 24/7 burning when the stove is really cooking, then I would not worry about it.