Question about 2.25 inch thick Tennessee Sandstone mantle mounting

[GreenGA]

Question... We've been asked to reface a brick fireplace with black granite tile around the firebox and hearth and MDF for the overmantle and the actual mantle will be the 2.25 inch Tennessee Sandstone noted in the subject.

We are planning to support the mantle at each end with a 8.5 inch solid column ( 2x material and plywood sandwich wrapped in MDF) and also rest the rear of the mantle on the .5 inch thick tile mounted on the fireplace face. The distance between the columns will be 58 inches. The mantle will be about 14 inches deep.

We're wondering if the two columns and the lip of the tile will be sufficient to properly support the mantle and prevent it from sagging in the future.

Thanks in advance.

 

[rizzoa13]

I'm not going to lie that doesn't really seem like enough support at all. Any way you could put some steel L brackets in the wall and then recess them up into a groove on the bottom of the stone?

If your doing new tiles under the mantle you could very easily open up the wall and put in blocking for a few L brackets and if sized correctly you could eliminate the vertical posts and float the mantle.

 

[tjbnwi]

The piece is about 200 pounds (I guessed the overall length to be 60"). With the back edge supported I think you'll be fine. Check with the stone fabricator.

Tom

 

[GreenGA]

Thanks for the replies and information.

One thing not clear in the original question was the over all length.  The length of the piece of stone is 75 inches, with the span between the columns being the 58 inches, and it is this span that will be supported at the rear on the .5 inch lip of the tile.

We found the a stone yard where the client picked up the sample piece and expect to make a stop later today if we can finish something first.

Oh, one thing more. The client would rather not see anything in the middle of the span,if possible.

 

[rizzoa13]

You could float the entire piece even if the client wanted to do away with the posts. I supported a poured concrete bar off of 2 pieces of 5/8" thick steel welded into an L. You can attach it to studding inside the wall and then cut grooves on the underside of the stone (easy to do with a grinder) the thickness of the steel to have it flush to the bottom and it dissapears unless you stick your head all the way underneath. Attach the stone to the steel with an appropriate epoxy and your set.

 

[GreenGA]

We went to the stone yard and spoke with the "stone guy".

With the two 8.5 inch solid columns on the ends and the .5 inch lip of the granite tile betweeen the columns, and the 2x wall that will be mounted to the face of the brick fireplace, and almost sit on the rear of the mantle and only going 14 inches deep on the mantle, we will be in great shape.

 

[tjbnwi]

About 228 pounds of stone.

Tom