I bit the bullet and replaced a rotten wood lintel with concrete one today.

I’ve just sat it on mortar and when it is hard tomorrow I’m going to try and knock some wooden wedges in the gap to see if I can lift the triangle of dropped bricks above and hopefully close the cracks.

Is this likely to be successful? I spoke to a builder who seemed dubious this would work. Lintel is just over a metre so not a huge amount of bricks to lift.

I also doubt it would work.

If you’ve got the new lintel in then shirley you’ve alredy lifted the bricks above…. of is the lintel in lower than it was before?

If so, maybe you could hire a couple of acrows, lift the lintel [and bricks above], reseat the lintel at the new height on proper pads or slate (depending upon the distance lifted) and repoint the brickwork.

The concrete lintel was not as tall as the wooden one so have a about a 15mm gap near the ends and 5mm in the middle where it has dropped, so hope to drive wedge into the middle section to lift the bricks.

Acroprops aren’t an option as it is a second floor above a single storey roof.

Pack with slate not wood.

Yup has to be slate. Lintel needs to be on reinforced concrete pads, probably not compliant with building regs as you’ve done it. I’d have gone for a properly sized steel lintel too. None of this stuff is expensive. My steel beam I got was 3.1m long and holds up half my house and was £105 delivered. Concrete pads very cheap.

Was planning on taking the wedges out once the mortar is set. I guess with slate you can leave them in.

Also wondering if I could use a long wrecking bar to lever the bricks in the middle then jam in some 15mm thick timber to hold it in place. Mortar the top, wait till it’s gone off then remove the timber. Anyone know how strong these lintels are, I’d guess that would be a lot of force and something might break – bricks or lintel.

Put your concrete lintel in with a mortar mix on top of it, jack the whole lot up with a couple of acrow props,
then point up under the lintel if there’s enough room, or pack with slate or steel shims.

Sorry, sharkbait has already explained this.
And of course concrete lintels are fine over doorways, that’s what they’re made for.

Stuff with papier mache, plasterboard over the top. Sorted.

Concrete lintol does not need reinforced pad stones underneath it, the span must only be about 700/750mm if the lintol is only a metre hardly needing a steel beam

Sorry, sharkbait has already explained this.
And of course concrete lintels are fine over doorways, that’s what they’re made for.

Can’t prop the lintel due to location and it is already mortared in (at the bottom not the top)

Also wondering if I could use a long wrecking bar to lever the bricks in the middle then jam in some 15mm thick timber to hold it in place. Mortar the top, wait till it’s gone off then remove the timber. Anyone know how strong these lintels are, I’d guess that would be a lot of force and something might break – bricks or lintel.

This sounds like a youtube fail video waiting to happen. Lintel won’t like a point load like that and likely crack.

I would get some across under the lintel, SDS out the new mortar and lift it up. Pack out under it with something solid and re-mortar.

IANABuilder

It would take some amount of force to crack a prestressed lintol by a human limb, maybe jumping on the end of a 6’pinch bar
I think the op is going about it ok, a couple of wedges fill in the beds with a square pointing key 8mm wide knock the wedges out next day and finish pointing off

I doubt you’ll get enough upward force with a wooden wedge; too much friction. You’re not just lifting the mass of the bricks, you’re also fighting the interlock friction in the joints (which is the only reason they haven’t fallen down completely). What does the wall support?

What does the wall support?

It’s an outside upstairs window on the gable end

Over that span it’s basically taking **** all load directly. You will see how the load has triangulated out hence other bricks having not dropped. Just as you say lever each one up and pack. I use slate and a big flat bolster to drive it in. Point up the remaining with a nice strong 3 n 1. The lintol as stated above can be bared onto normal brick. What depth is it, standard 65mm?

If I’ve read wrightyson’s post right, that’s start at the top of the triangle and lift each brick – sounds good, and I’m sure he’s done it so it must work. Not knowing the age of the building and the roof construction, mention of a gable end raises a question: do the rafters sit on the side walls, or on a big (eg, 14″ x 6″) purlin that lands on the gable, above the window? So long as there’s no roof support going onto that triangle of brickwork, I’ll agree there’s no problem.

It was on a rotten wooden lintol before with little movement. It’ll be reet.

What depth is it, standard 65mm?

Yep, 65 x 100 x 1050mm, spanning a 790mm opening on a solid 9″ wall

do the rafters sit on the side walls, or on a big (eg, 14″ x 6″) purlin that lands on the gable, above the window? So long as there’s no roof support going onto that triangle of brickwork, I’ll agree there’s no problem.

On the side walls mainly but there is a loft conversion which means where the opening is for the stairs the joists go into the gable end, but only a shortish span – 5-6ft