floating slab mantle

[Scott Welty]

I'd like to try the method shown in this link... (https://theverybasic.wordpress.com/2012/04/20/recycled-floating-mantel-6/)

I have 3x7x55 inch white oak rough hewn beam to use. I have located 3 studs above the fireplace. Thinking of useing 5/8 x 10 or 12 inch lag screws and then cut the heads off. I'll use one of those portable drill guides to drill straight into wall and into beam.

Anyone every tried this? Do I put any goo or glue into the holes?

Anyone want to talk me out of it?

Scott

[Wayne Lomman]

Scott, this should work OK. Three steel pins 5/8" diameter will be adequate. Just make sure you drill your studs in the centre so that the pins are well seated. I am in two minds about adhesive - probably it will sit tight without it but if it is a bit rattly, some construction adhesive in the hole will be enough. Don't let anyone talk you out of it! Cheers.

[Scott Welty]

Thanks Wayne...at least you didn't say, "Go ahead . . . stupid!" That would have been my dad.
Scott

[Andrew Hughes]

Thanks Wayne...at least you didn't say, "Go ahead . . . stupid!" That would have been my dad.
Scott
Now that's funny..
Your post reminded me of a mantle I did with a French cleat in the back.The wall needs to be fairly flat and a good piece of 3/4 inch plywood is screwed to the wall with a 45 on top.The beam has a pocket in the back with its 45.
Its very strong

Aj

[Scott Welty]

Yes! I'm hanging a large reclaimed wood unit on a garage wall with french cleat.

[Jamie Buxton]

Where do you live? Here in earthquake country, doing it without adhesive would make me nervous.

[John C Bush]

I attached a 6"x10"x60" mantel in the same fashion but used a 2x6 as the template to help with perpendicular alignment and transfer hole position to mantel. Find stud center, mark on 2x, drill template holes on DP, use to drill both into wall and back of mantel. For overkill I drilled access holes in bottom of mantel intersecting the retainer hole, placed threaded inserts and used screws with heads that fit in the access as set screws, plugged access holes--worked great. When I placed the mantel on the retainers, I had to "persuade" the mantel on with a soft blow hammer so the set screw idea was not really needed but was fun to try anyway. Good luck.

[Scott Welty]

Love the set screw idea! Over-engineered just the way I like!

[Scott Welty]

Chicago - no earthquakes here...until the Cubs win the World Series!

[Jerry Miner]

Scott--

I've done this several times, both with and without adhesive.

I pre-install the lags, then remove them and cut the heads off "on the bench" to eliminate the vibration at the wall, then re-install the lags with vise grips.

On my first installation of this type, I drilled two small holes in the top surface, in line with the lags, then pumped epoxy through a syringe into the first hole, pumping until the epoxy oozed out of the second hole--indicating that the void was filled.

In subsequent installs, I have eliminated the epoxy. The lags alone seem to work fine.

If an earthquake shakes enough to make a mantle like that walk off 6" of lag screw, there will be way bigger issues to deal with (like a complete building collapse) than a falling mantle, IMHO.

[Danny Hamsley]

I have installed several of these. Take some 3/4 threaded rod, drill into the studs, tap the threaded rod into the studs letting them protrude 3/4" of the width of the mantle from the wall. Place the mantle against the rods where the rods are centered and the mantle is level. Tap the mantle so that the ends of the threaded rod (that are protruding from the wall) make a mark or impression on the back of the mantle. This tells you where to drill the holes into the back of the mantle. Drill a level hole into the back of the mantle to the depth that the rods are protruding from the wall plus about 1/8" and slide the mantle onto the threaded rod. Friction from the threads on the rod will hold the mantle tight to the wall if you drill the holes the same diameter as the rod, in this case 3/4".

[Scott Welty]

Danny,
Will threaded rods rather than lag screws drive drive themselves into the studs? I like the idea of the friction you'd get at the mantle end though.

[mark mcfarlane]

Chicago - no earthquakes here...until the Cubs win the World Series!

So you're safe for another 60 years.

Sorry, old Cubs fan here. I ditched school a few times to go to the games. The police would occasionally stop us and say 'why aren't you in school'? We'd say we were heading to the game and they'd laugh and politely give us instructions to the right train. $1.50 for bleacher seats in left field. Gone are those days.

[Danny Hamsley]

Scott,

Using a wooden block to protect the end of the threaded rod, you can tap the rod into the hole in the wall into the studs.

[Paul Girouard]

Your plan will work fine .
On this driftwood one I bored into the CMU , set the threaded rods , next day bored 1/8" over sized holes in the wood pumped in a bit of construction adhesive, used a dead blow mallet to seat the mantel then propped it over night after we leveled it in as best we could. Being driftwood , it was more a by eye leveling process.

Mason laid the stone around it , very solid.
It was about 12" to long so I did have to cut it off for length, then used a Dremel tool to fake the driftwood look on the end grain.



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[Paul Girouard]

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