Fireplace lintel query

[Will]

Hi All,

We've removed an old fireplace surround in our Victorian property along with the outer hearth as part of refurbing. It looks like previous owners at some point had the original fireplace opening reduced in size and there's a lintel that's propped on top of two brick columns that aren't tired into the original brickwork.

The aim is to remove the inner hearth so we can fit a new cast iron fireplace but the two brick columns (and the lintel) are sat on top of this inner hearth and we're concerned that the lintel is structural.

Given the brickwork arch above the concrete lintel, is this lintel is actually structural? Our backup idea for fitting the fireplace is to use an angle grinder to cut away the necessary space for the fireplace and leave the bricks/lintel in situ.

Any advice and experience welcomed! Thanks

 

[Flyfisher]

It doesn't look structural to me, though I wonder why they used such a large lintel - perhaps just using what was easily to hand?

I opened up a large inglenook fireplaces in our house, which had three old fireplaces within it. None of the 'added' fireplaces were structural and had (thankfully) been built with a very weak lime mortar such that the bricks were easily removable, leaving the original inglenook brickwork unscathed. If you consider that each later fireplace was built within an already existing one then it's not surprising that none of them were structural. Or rather, they only had to support themselves and not the preceding opening.

This looks to be the case above. The earlier opening was clearly built to be self-supporting without the need for the later addition, so the removal of the added brickwork/lintel should not cause any issues, as long as the original brickwork and mortar is still in a sound condition.

 

[Stevers]

That could be a pre-cast concrete throat to make a more efficient flue - hence the depth.

 

[stuart45]

It's quite common to stick a throat lintel in when setting the fireback into the builders opening, although that ones a bit bigger than the ones I've used.

 

[housewinnie]

Is there a metal flat bar under the arch

 

[Flyfisher]

I've seen metal bars under brick arches but have always assumed that they were only intended to provide support to the bricks in the arch itself while it was being constructed, rather than to provide any overall structural support to the final wall.

 

[Stevers]

The thick wrought iron bar under the arch (4' span) on my big basement chimney breast is severely corroded, so whilst the way it was anchored at each end says it was intended to provide horizontal restraint, the level of wasting to almost nothing at one end and the stoutness of the masonry at each end leads me to hope that it was overkill. The arch bricks never seem to have sat on the curved bar which closely follows the line of the arch. When I repaired the arch and the abutments at each end I was still able to put a bit of tension into the bar with a G clamp before the fully set NHL mortar locked it all tight. Should that bar snap at some point I'd be very surprised if the arch went on to spread.

What I did notice was how my method of repairing the arch really tightened up the triangle of slightly dodgy random stonework above!

 

[Flyfisher]

Fair point about the horizontal restraint in a chimney breast, where a brick arch may have minimal horizontal bracing. But where an arch is built in line with the wall, as in the OP's photo I don't think additional bracing would be required to prevent the lateral movement you've noticed.