fixing heavy oak mantle to brick chimney breast

[brogang]

Hi, new to the forum!

I've bough an old lump of reclaimed timber from a merchant which i've had blasted and cleaned. I'm going to use it as a mantle and want to fix it before i get the room replastered. I haven't a clue how to do this though?

Am thinking of a rod fixing - bore into the back of the log and slide it on but how do i do this and is there a better way?

Obviously i don't want any fixings to be visable.

Thanks!

 

[noseall]

large pieces of oak are usually built-in to fire places. is this not an option?

 

[brogang]

Hi noseall,

No it's not unfortunately. I've striped the plaster off to the bare brick and just getting it re-plastered. Not actually rebuilding any brickwork just wacking up the beam flush onto existing.

 

[noseall]

this MAY work.

buy three 600mm x 5mm straight galv pre drilled straps.(same as restraint straps).

fix 'em to the back of the beam, three 4" screws in each strap.

fix the straps so that there is steel protruding above and below the beam.

fix the beam to the wall through the straps.

plaster up. dunno if this is sufficient, but maybe worth a go?

 

[RigidRaider]

We did the same thing with a big heavy lump of Canadian cedar. We plastered and painted then decided the rather stark fireplace needed finishing so bought this piece. I measured carefully, then put two large dome-headed screws in the wall with brass mirror plates sunk into the back of the beam. After carefully adjusting the depth of the big screws, I was able to drop the beam onto them where it sits, looking exactly as if it's part of the fireplace. In future if we want to redecorate we'll simply lift off the beam so as to avoid messing around with masking tape.

Doing it this way would avoid the problem of the wood shrinking and leaving a gap around the plaster.

Rather than try to measure to within 1-2 mm, if I did the job now I would simply drill and fit the screws then make a template out of stiff board to show me the required distance between the holes in the mirror plates.

If standard mirror plates weren't strong enough - and they should be as they will be in tension - then you could get some square pieces of steel plate and drill & slot them to accept the two screws. You could screw these plates into recesses in the back of the beam, even setting them in Plastic Padding or Araldite if you wanted to make it really strong.

If your beam is really heavy you could scale this up by buying a couple of long coach bolts and setting them in holes in the chimney breast, cemented in with a two-part resin that's made exactly for this kind of job. However you would lose the depth adjustability so threaded rod with a couple of nuts might be better, almost like mounting a WC or a basin to a wall. Alternatively, could you drill and bolt right through to the inside of the fireplace? You can buy bolts or studs with one end tapered and threaded to screw into the back of your beam.

When replastering the chimney breast, make sure you chip off the old plaster for a good distance away from the fire, otherwise the new plaster will expand and contract with the heat at a different rate from the old and cracks will soon appear along the join. Best to do the entire front face so the stresses are evenly dissipated.