How to mount mantel

[73blazer]

I'm torn as to how to mount my new mantel.

Last year I tore out our old cheapy builder special ZC unit and replaced it with a HeatnGlo North Star. I've yet to finish off the surrounding area and hearth extension.

I've got a 9x12" old barn beam that I've planed down and want to mount. Being in a room that's 28' tall we wanted something a little more substantial because the old mantel was basically a thin piece of oak and looked kinda dwarfed and small on that wall. The wall is cultured stone up to the top. I'm going to mount it by screwing a 2x8 cleat to the back of the chase wall inside the chase and send some pipe through the wall and screw some pipe flanges to the 2x8 cleat on the back and have the pipe sticking out the front and drill same diameter holes in the back of the beam and slide it on the pipe. No corbels or brackets or anything.

So during the replacement process I tore off the cultured stone up to the old mantel. I also removed the old mantel and there's a nice clean line in the stones at that point because there was a 2x4 cleat set against the OSB which the mantel was simply screwed to (it was a small thing oak mantel, not very heavy at all. Behind the cultured stone is 5/8" OSB against a 2x6 wall.

SO in this picture, all the stones from the mantel (barely shown on the top of the picture) are tore off and the OSB exposed. We plan a different type of stone on the lower portion of the wall around the fireplace.

Since the exposed face is smaller than the old fireplace, we didn't want to piece in new pieces of stone and try to match the old stone and then the grout is different color, so we just decided to do a different stone all together on the lower portion. There's 28' of stone going up to the peak, so we'll have kind of a 2-tone thing going.


Now, the question is, are mantels usually mounted on the face of a cultured stone wall or should I mount the mantel directly against the OSB with the top edge up against my clean line of stones and put new stones in underneath it? That's certainly easy, but it invades the 60" clearance to bottom of unit by 3.5 inches. So I'd have to cut (which means massive mess or several hours creating a plastic enclosure which I'm pretty good at from my asbestos abatement days) a new line in the cultured stone 3.5" higher. Or, I can just get my mounts in place and get the new lower stones in place and mount the mantel sticking out more than 12" the code specifies as maximum which means I'm gonna have to cut 3" or so off the back of the beam, which means creating some custom fence/guide for my bandsaw to get a clean cut.
Aside from that, I just don't know how a mantel directly mounted to the OSB might look, as it seems to me most mantels are mounted on the face of already existing stone surface, or are they?

So options are:
- Cut stones and mount the mantel directly to the OSB then install lower stones
- Mount the mantel directly to the OSB and install new lower stones which invades 60" height requirement for mantel by 3.5"
- Get mounts in place through the wall and install new lower stones, cut back mantel by 3" or so and install against face of stones.
- Your suggestion here!

Thanks for any help!

Ken

 

[masonman]

I've built many fireplace and hearths out of just about anything you could imagine. Mounting the mantel is always something to consider largely. I'll only suggest one possible method out of many. Would it be reasonable to saw out some of the OSB you have removed the stone from and fasten some, possible 4x4 or so to the 2x6 studs. 2 outriggers so to speak. Maybe you could find some of the barn plank to make some from? Then you have to decide weather or not to install the mantel against the OSB or install it after the stone is reinstalled. Either method will work, you seem to understand the difficulty making the mantel fit the stone rather than making the stone fit the mantel.

 

[73blazer]

So it's done both ways then? My main concern is I want to mount the mantel to the OSB and make the stone fit around it, and I can't say I've really seen that and thought it might look really goofy or something.

 

[ddemmith]

I just finished my install and ended up not building the mantel into the stone. I feel it would look unnatural as you would compromise the the stones random positioning if you had 2 horizontal lines of stone around the mantel. Just my opinion.

As far as brackets, I screwed 3 'L' brackets to the 2x4's I used for backing then set the mantel on. Only problem I have run into is the rough sawn beam I chose warped over the summer both length and width. I plan to cover the brackets from the bottom with pieces of the wood once I get the beam squared up.