#12
Nephew is building fireplace surround intended to impress his great-grandchildren.  He wants no fasteners to show on the surface.  Family cherry.  The mantel board is 7’ long, 1.625” thick, and 9.5” wide.  The rear 4” will rest on the surround structure and two corbels (vertical grain) extend almost to the front edge.

We are thinking dowels glued into the end grain of the corbels.  There should be no expansion issue here and he wants a good tight fit.

But what about the back edge near the wall.  

How much, if any, room should he leave for expansion there?  
Does the edge need to be fastened?
If so, how to make it invisible?

Thanks in advance.
Carolyn

Trip Blog for Twelve Countries:   [url=http://www.woodworkingtraveler.wordpress.com[/url]

"It's good to know, but it's better to understand."  Auze Jackson
Reply

#13
i mounted a mantel over my nieces fireplace- 3" thick red oak from a tree in her back yard- by using a forstener bit to hog out some holes to run some lag screws into the framework, then cut some face grain plugs to plug the holes. i cut a lot of plugs so i could match the grain some. they really arent seen ever but blend into the rest of the mantel real good.
Reply

#14
Sorry,  I am having trouble understanding exactly what he wants to do.   He can make the mantle appear to float by cutting pockets in it -  this is not exactly the way I have seen it done, but it gives the general approach.  https://www.youtube.com/watch?v=ZeyLj0Ppukc

Here is another variation that would work better with the wood he has  https://www.youtube.com/watch?v=wki3wMAbtLg
Reply
#15
I see a number of shows, including Stone House Revival, where drill holes in the back-side of the mantel and slide it onto headless lag screws.  I believe they use some sort of adhesive to hold the mantel to the steel shank.

I would consider using a stopped sliding dovetail joint to attach the corbel to the mantel.
Macky

The wheel of Life is like a toilet-paper roll, the closer to the end you get, the faster it goes around.

Reply
#16
This is not the single mantel board that seems to float. Imagine 1850-1900 surround with lots of wood structure beneath the top that surrounds the opening and goes to the floor. This structure extends nearly 4” from the wall. The corbels extend outward from there nearly to the outside edge of the top board. The mantel board needs to tie solidly to the underlying structure with no gaps, yet allow for expansion across its 9.5” width.

Details differ, but the construction is similar to this:

[Image: ACCF35-D4-3191-4-FC2-B592-C5-CC55-D6-B02-A.jpg]
Carolyn

Trip Blog for Twelve Countries:   [url=http://www.woodworkingtraveler.wordpress.com[/url]

"It's good to know, but it's better to understand."  Auze Jackson
Reply
#17
I'll add something to think about. When my brother built the mantle and surround for his fireplace, he arranged it so the mantle can be removed with no tools. There are pins that going in from the top near the back edge to keep it in place. He did that so when the time comes to paint the wall again, he can remove the mantle easily and paint behind it. No need to mask it
Reply
#18
What a wonderful idea! If I told Nephew that now, he'd probably shoot me—he's too far along.
Smile That would also make it easy to transfer to another house if necessary.
Carolyn

Trip Blog for Twelve Countries:   [url=http://www.woodworkingtraveler.wordpress.com[/url]

"It's good to know, but it's better to understand."  Auze Jackson
Reply

#19
(07-27-2019, 09:58 PM)MsNomer Wrote: What a wonderful idea!  If I told Nephew that now, he'd probably shoot me—he's too far along.  
Smile   That would also make it  easy to transfer to another house if necessary.

No need to get shot over it.
Wink

He found he can pull it out from the wall very slightly to hide wires for the holiday lights his wife likes to put up there.
Reply
#20
To your original question, I'll vote no worries on expansion - with the caveat that I am far from being expert.
Thanks,  Curt
-----------------
"Life can only be understood backwards; but it must be lived forwards."
      -- Soren Kierkegaard
Reply
#21
How about sliding dovetails.  I would probably do 2, fairly wide (at least 1") dovetails, one up each leg of the mantel.  I wouldn't use one continuous dovetail strip, I have tried them and they are too prone to binding.  Machine a dovetail strip, cut about 1/2 dozen 6" lengths, 3 for each side, hog out the dovetail to make slots, below where the strips will mount, mount the strips on the wall and slide the mantel home.  You don't need a starting slot for the bottom strip, but I would raise it at least 1" off the floor, a small angle on the head of each strip aids with alignment.  I might also consider a small strip in the center of the header.

I imagine that it's too late now, but I have seen mantels where the legs are hollow and the "door" has concealed overlay hinges and rare-earth magnets, makes for a great hiding place.
Macky

The wheel of Life is like a toilet-paper roll, the closer to the end you get, the faster it goes around.

Reply
Mounting Mantel Board on Fireplace Surround


Forum Jump:


Users browsing this thread: 1 Guest(s)

Product Recommendations

Here are some supplies and tools we find essential in our everyday work around the shop. We may receive a commission from sales referred by our links; however, we have carefully selected these products for their usefulness and quality.