he Hearth Room saved a family’s home..maybe their lives. Important post for masonry fireplace and in

[elkimmeg]

Everybody owning an insert should remove the surround trim and examine their fireplace opening. Look up at the angle front of opening and called lintel and see is all is tightly sealed also look at the damper flange. If mortar is missing or anyone can see any spacing between brick, you have a real safety problem. Most inspections are concerned with venting issues. Overlooked, is potentially very dangerous deficiencies of the original fire place design. This from a post today presents the clear and present danger.
https://www.hearth.com/talk/threads/382/


“To all,
This is extremely helpful.

“Elkimmeg , you pointed out about the fire… two towns over, I just looked up in that crack and there is a wood header exposed. I think you all just saved me more than my smoke problem, but you may have also saved my home and family… This information is much appreciated.”

“Again, I can not thank you all enough for this extremely helpful information.

It really concerns me that after having 3 “professional” chimney and fireplace repair personnel to look at my fireplace, that not one mentioned this crack --even after I pointed it out to them. They assured me that by just rebuilding a crown on top of my chimney, waterproofing the bricks outside the chimney, and siliconing the gap between my home and chimney that this would all stop the smoke. $400 later it obviously didn’t stop the smoke.

That’s pretty scary.”

 

[webbie]

Everybody owning an insert should remove the surround trim and examine their fireplace opening. Look up at the angle front of opening and called lintel and see is all is tightly sealed also look at the damper flange. If mortar is missing or anyone can see any spacing between brick, you have a real safety problem. Most inspections are concerned with venting issues. Overlooked, is potentially very dangerous deficiencies of the original fire place design.
------------------------------
“Elkimmeg , you pointed out about the fire… two towns over, I just looked up in that crack and there is a wood header exposed. I think you all just saved me more than my smoke problem, but you may have also saved my home and family…

Elk is correct in pointing out the fact than MANY, if not MOST masonry fireplaces are constructed improperly and there is wood too close to the lintel or to the sides. It is very normal for a crack to develop in both of those areas (where the exterior facing meets the firebox) because of the different ways that the house foundation and the facing/hearth (which is usually supported on wood frame!) settle.

BUT, it is not normal for there to be wood very close when these cracks occur. Not being a mason, I can't give you the spec, but I know it is at leat 8" on the side and more on the top.

There is some good news here. The installation of most fireplace inserts - as long as they have a pipe through the damper (at least) would seem to help the situation, since now the fire is contained in a double wall structure and also the pipe puts the exhaust up past these areas....

Of course, we all know that in ALL prefab fireplaces, wood is MUCH closer than this, so just the fact that wood is there is not the key to danger or safety......

All in all, it would seem this is one more reason for not installing big honking old radiant stoves on the hearth. Most newer units have closer clearances, double wall, etc.

This subject begs the question - well, why aren't more houses burning down if millions of such problems are out there?

In my opinion, the answer is partially luck! A lot of people use their fireplace rarely. Another big factor is that air cannot easily get into the wall interiors, so even if these framing members are overheated they are less likely to burst into flame!

I'm sure Elk and I would agree that if you ripped the front facing off many heavily used fireplaces, you'd see some charred wood behind them...scary....

This gets back to one of my pet peeves...the lack of enforced standards in the brick and masonry industry. As mentioned before, that industry lobby has been effective at keeping fireplaces less safe than they could be!

Want a great masonry fireplace? Look at Isokern - built of volcanic rock and tested, tested, tested!

 

[wg_bent]

Wow, those Isokern's look cool. I do however like the Tulikivi's also for a masonry "fireplace" (I guess calling a Tulikivi a fireplace is a bit of a stretch though)

If I were to win the lottery...one of those would defininitely be in the plan.

 

[elkimmeg]

Craig there are a lot of people living charmed lives Why have there not been more fires I posted a stat a while back the numbers of fires is alarming This might explain why and no you are not out of danger but living on borrowed time
What is pyrolasis? Wood, which has been exposed to excessive heat, changes its molecular Structure and become more flammable. It will flash at a much lower temperature or the wood has become pyrolized.

In a neighboring town a chimney was built incorrectly. Mortar was missing creating a pathway that led to the framing header. It flashed 8 years latter ( pyrolasis)
Final inspections I check for such possibilities I know many bricks are cored and it is imperative that everything is pared and sealed.

 

[Curtis Koble]

I have a very small 1/8" to less than a 1/4" gap. Can I just use High temp silicone to seal it. Can not see any wood looking up thru the crack but I'm sure it's there. Wow do you learn a lot in here Thanks.