I have a brick fireplace surround and hearth, that I want to cap with a heavy oak mantle. The question I have is, would a solid piece of oak approx. 3″ x 3″ x 8′ be stable, or would I be better off wrapping an inferior quality wood with oak. I’m leaning towards the solid approach, if it won’t twist or check, because I would prefer the heavy look of a solid timber. If I go with the solid mantle, does anyone have a good source for the type of dimensions I’m looking for?
Steve
Replies
Steve,
I'm also in the process of re-doing a fireplace. The mantle I'm replacing is large and I'm fabricating a slab mantle of Teak, 8' x 8" deep x 6 " high. I've wrestled with the same decisions you're going through.
I'm going with a construction of an outer shell of teak over an inner core of fir 2 bys. The fir gets bolted to the wall studs.
The tolerance between the outer surface of the core and the inner surface of the teak box is a very snug fit all around as one would do in mortise and tenon construction. The box will get glued to the core.
Because I like end grain and I want the box to look like a solid beam of teak, it is constructed so that the ends ARE end grain. They are 4" long pieces glued into the box construction oriented so that their end grain shows at the ends of the "beam."
The front of the box is glued up of several thicknesses so that their edge grain is visible to the observer. It is very hard to distinguish glue lines with this orientation of wood and the whole box looks like a solid slab of teak.
I believe that this construction will fare better than solid wood. Besides I couldn't get (or afford) a piece of solid teak as big as the box.
R
Rich,
Thanks for you reply. I like the idea of using endgrain on the ends to make it look like a solid piece. Did you build out the 2 bys to the full depth of the mantle, or was it a single 2 by attached to the wall? In other words, is it a completely solid structure, or is there a hollow space between the face and the fir? I was thinking of building out the 2 bys to the full dimensions of the mantle minus the oak stock thickness, and building the box in place. Am I just making more work for myself?
By the way, your reply threw me for a loop at first, since I work with a guy with the same name as you. Your not in the FR business are you?
Steve
Steve,
The mantle is a completely solid structure. It's not in place yet, but the 2 bys completely fill the box formed by the teak (I didn't want anything to sound hollow). They're built separately, esssentially a large motise and tenon structure. I don't see why you couldn't build it up in place.
FR business??? Furniture Refininshing? Financial Repossession? Football Recovering?
Nope none of those!
R
I decided to go with the wrapped approach, and got some very nice looking quartersawn white oak to wrap the mantle with. I have cut all the pieces to size, with the joint between the face and the sides mitered, and the top and bottom cut to sit inside the face and sides. The top and bottom of the mantle won't be seen except by someone standing or sitting on the hearth. Besides, the joints shouldn't be very noticable anyway.
I would like to avoid having any visible nail holes in either the face or sides. Would glue and screw blocks on the interior of each joint be strong enough, or would bisquit slots and glue be a better way to go. I don't currently have a bisquit joiner, so justification for a tool purchase is always welcome. Either way, I am going to be attaching the box to a support of 2bys ala Rich's method. If I go with the screw blocks I will have to cut away some of the support to accomodate the screw blocks, but that should be simple enough.
Can you tell this is only my second significant project? Just wait until I get ready to finish it, then I'll have even more questions.
Steve
Steve,
Being right in the middle of a fireplace remodel myself (I'm fabricating an aluminum fascia to the front - that's another thread), I've accidently gotten an education in mantle design and fire safety.
There are codes and specifications regarding the distance of the underside of the mantle from the opening of the fireplace. And the shape of the underside of the mantle. Seems that slab shaped mantles have the annoying habit of catching on fire. Mantles trap the rising heat from the opening and the shape of the underside can be a factor if the mantle is close to the opening.
Our fireplace expert/salesman/installer has shown me pictures of mantles that have partially burned, and houses that have been destroyed by fires that started by the mantle's catching fire.
Check with your local experts to be sure your design is safe.
R
Rich,
The fire codes around these parts dictate the minimum distance from the firebox opening to closest combustable material in each direction. 24" depth of hearth, 18" above the firebox, 12" to the sides, etc. With the height of the brick surround above the firebox I am at least a foot outside the minimum distance required. The mantle will sit on top of the brick surround, and project approximately 2 1/2" past the brick. Not a lot of exposed surface on the underside of the mantle to trap heat. I will be watching it though.
Ironically, the FR I spoke of in one of my previous posts is short for Flame Retardant, which is the business I'm in.
Any thoughts on my questions on constructing the mantle?
Would tried and true oil varnish over black milk paint be a safe finish to use on my new Mantle. In other words will my house burn down?
Circle,
I don't know if your house will burn down, but Tried and True would not be my choice for the top coat on paint. It is an oil/varnish mixture, intended to be applied as a close-to-the-wood, rub-in, rub off type.
It wouldn't hurt anything if you use Tried and True in your application. With many coats, it will act as a wiping varnish and give you a very thin varnish coat on the paint. Why not just brush on an alkyd or poly varnish and get a good varnish protective film over the paint?
R
Rich,
About a year ago I did my living room floor in Quatersawn heart pine (Old growth) real nice stuff. At the time I ordered it I also ordered some 1" roughsawn stock for the mantle. To make a long story short the Mantle is just about done and I've been fooling with some finishes. My wife wants it black but the stuff is so dense it won't really take a stain(MInwax Ebony). I've been experiencing with the milk paint and a thin coat of Pitch Black,let dryand then rubbed out gave me a real nice color as well as let the beautiful grain show through. So it kind of would be close to the wood. But I'm not a tried and true fanatic i just happen to have a can around. Do you think a wipe on finish in this situation isn't enough protection?
I'm not a fan of the Tried and True product. I have had nothing but poor results with it in the manner that it's intended - as the primary finish on raw wood. I really don't think that it would be a good choice over paint.
R
thanks for the input
I believe oak is one of the woods that can be ebonized with a rust and vinegar solution. The color comes from a chemical reaction rather than a pigment, so there is no problem with it being absorbed into the wood like a stain, nor does it obscure the grain like paint. Do a search for ebonized or ebonizing.
Steve,
Nothing to add. Good luck!
R
I think properly fitted glue and screw blocks will be much stronger than properly fitted biscuits. Just compare the glued surface area of the two techniques.
Steve,
Solid oak, or any wood, will probably warp. The location of the mantel so close to the fireplace's intense heat source means radical changes in both heat and humidity.
With that in mind, consider the room. In a formal room such as a dining room or parlor, the rustic look of a cracked, somewhat warped mantel piece may look out of place. In a less formal room, however, the piece may add charm, especially as the wood ages and takes on that wonderful patina.
Jeff
my mantle is a piece of red oak 2 1/2 X 11 x 8 FT. No warp in 12 years. Art
It's fairly uncommon for oak that thick not to check. Sure, there's exceptions to everything, but most kilns limith their red oak to 8 or 10/4 to help prevent some of that. My vote's with banding the stock by laying out a torsion box, wrapping the face, sides and bottom with solid (matching grain even better). Haven't really considered end grain used as a veneer, but hey, why not? Sounds reasonable enough.
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