How to install a throat forming lintel

[dojojones]

Any advice much appreciated. I have removed a gas fire and had a gas safe engineer cap off the gas pipe away from the fireplace. I want to make he opening usable for a solid fuel open fire. I have had a HETAS engineer around and he said everything is good except that i need to put in a throat forming lintel around 60cm up from the existing floor.

Currently the opening is 94 cm high from floor to flu and existing lintel, and around 47cm wide.

The lintel i have bought is the smallest i could find and is 86cm wide (same as existing load bearing lintel). So i need to knock out some bricks 30 cm or so below the existing lintel and put this in.

My question is: how do i support the existing lintel while i am removing bricks? At first I though of hiring a prop and putting it in the centre of the existing opening, but then it occured to me that in doing so I wont be able to get the new lintel in as the prop will be in the way. Am I missing something, is there an easy way of doing this? Or maybe i shouldn't worry about support? Any ideas?

Thanks.

 

[RedHerring]

It's just the same as taking out a wall. You don't put the props under the wall. Otherwise you wouldn't get the lintel in. You use 'needles' under the wall and support each end of the needle. So you'll need two props.

 

[RedHerring]

Incidentally, I'm not in a position to advise you on the lintel choice, positioning, etc. You'll need to satisfy yourself on those matters, such as effect of heat on the lintel, choice of brickwork, fire cement, etc.

 

[dojojones]

So if i understand correctly I drill a hole above the existing lintel and insert a needle and then put one prop in the fireplace opening and one in the room outside the fireplace. Only problem with this is the bottom of the existing lintel is flush with the bottom of the flu. If i drill through the brick above it, the hole would go into the flu.

Or have i misunderstood? Thanks Red Herring for getting back to me.

 

[Chukka63]

i think your fireplace will hold up with no needle unless the brickwork is incredibly crumbly.
have you tried lighting a fire and seeing if the smoke goes up the chimney as it is???

 

[RedHerring]

Why remove the existing lintel? Support underneath it as you say, with a prop in the fireplace and one outside of the fireplace. Then build in your new lintel. Build up to underneath the exisitng and when all is set and cured, remove your supports.
Search for something like removing a wall on the forums for further advice.

 

[stuart45]

Can you stick a photo on?

 

[Nige F]

Think you`ll find a throat forming lintol is a special shape to go with a fireback

 

[dojojones]

OK thanks for answers. Just had an idea. If I support the existing lintel with a needle underneath it on two props should give me room to put in new lintel. Seems obvious now. I was still keeping the old lintel it was just that i stupidly thought the needle would go in the brickwork above it and not below it where i gues it acts as a platform.
Thanks for the help

 

[dojojones]

Hmmm..can't seem to get props small enough. HSS starts at 1m.

Do you think 3 by 2 timber would be strong enough? Or any other suggestions?

 

[gday2uk]

Yes timber strong enough.
You will find that when you start it will take a lot of effort to remove bricks and wonder why you ever though about support in the first place. If you bang hard enough worse case scenario is a triangle of bricks coming away from the middle of the breast. The whole breast wont collapse

 

[RedHerring]

You will find that when you start it will take a lot of effort to remove bricks and wonder why you ever though about support in the first place. If you bang hard enough worse case scenario is a triangle of bricks coming away from the middle of the breast. The whole breast wont collapse

I made the assumption that the op will be removing the 'support' for the original lintel and he doesn't want/need to remove the lintel.

 

[Chukka63]

we're all guessing cos no pics etc but the throat lintel wouldnt site on the front face of the breast anyway and presumably there is a lintel in the front 4" of the breast or a self supporting arch.in which case the breast wouldnt go anywhere and the throat lintel is norma;;y just to guide the smoke to the flue and carries little weight in retrospect.
like mentioned before,i wouldnt bother with supports