Thread: Mounting a large solid slab mantle to a wall

Hi jjavaman ,
there are no stupid questions ,
there can be some bloody silly answers tho

My way would be to ,
Use 10mm threaded steel rod , as a glue dowel , about 100mm into the slab , and a at least 50mm into the studs , allow extra for the wall lining if it is on .
Drill horizontally into the studs , with corresponding holes into the mantle.
Dry fit the slab . If you need to slough out the holes a tad , or tap the rods over a bit here is your chance . Keep things as tight as possible , within reason .
Figure out whether the rods are best put into the wall or the slab first .
Use a good glue , or epoxy , and coat the rods well
Lay mortar along the top of the stonework , but insure that as the timber is driven on , the mortar does not build up behind , and prevent a tight fit to the wall.
Don't do it on your own , and , use a hammer block .

Most importantly , have fun , and post pics

Hi Darren

My previous house had 2 x 10 inch shelves attached directly to solid brick walls. Not as massive as your mantle slab but after 30 years is still going strong. The technique seems the same as Jocks.

The previous owner had drilled the brickwork and then epoxied 8 mm (5/16 inch) steel rods into the holes. He then just slid the shelves over the rods - three rods per shelf - about 8 ft long.

I later asked the gentleman how he lined up the holes. He said he got three small lengths of rod, filed a point on one end, drilled through that rod and put a stopper nail into the hole in the rod. He then put the rods into the brickwork holes - the nails stopped them going too far. He then just pressed the shelves into place and the pointed ends on the rods put witness marks onto the shelves.. Then he drilled 8 mm holes through the witness marks.

He said that he then epoxied the longer rods into the wall. After he had ensured the holes in the shelves lined up properly he bent one of the rods a little. The resulting tension was sufficient to hold the shelves in place without any glue and leave them removable in future, if needed.

I used to remove the huon pine shelves to polyurethane them and to paint the wall behind them.

Cheers

Graeme

Originally Posted by jjavaman

I have a solid (yellow cedar, I think) slab (approx 25cm x 20cm x 183cm) that I want to use as a mantle. The slab is extremely heavy. . I'd guess it probably weighs in at about 200 to 250lbs (90 to 115 kg).

Wow, that sure is some mantle. Seems a lot of weight hanging off 2X4 studs.

Originally Posted by munruben

Wow, that sure is some mantle. Seems a lot of weight hanging off 2X4 studs.

That is why it should not be hanging off the wall .
It sits on the stonework , the attachment to the wall is to keep it in place