Victorian fireplace - crumbling mortar - arch lintel

30 Oct 2022
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United Kingdom

This is my first post and we're not experienced DIYers, but we're trying to learn.

We want to put in a stove in our bricked up fireplace in the future (once we've got a bit more money saved up), but are trying to get the dirty jobs done before re-plastering the living room. We've removed enough plaster from the bricked up fireplace to find dark old bricks on each sides and an old arched lintel (see picture). The builders opening looks to be around 100 x 100 cm.

We want to continue to remove the bricks filling up the builders opening, but the mortar between the old bricks in the arch is very crumbly and falls away like dust if scraped. Is there any way we can repoint the arch bricks ourselves or is this the point in time where we call in the professionals and get them to help us out? I guess it's not very clear right now, as well, how well the side bricks are supporting the arch. (I may need to remove a little more plaster to see better. I currently don't feel very confident removing the new bricks in the builders opening if the arch lentil isn't structurally sound.

Any advice and guidance would be very helpful.




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Have a bit of a dig just below the arch - you will quite likely find a flat steel. That steel may continue through the sides and be bent down agaisnt the brick under the side plaster, both supporting the arch and stopping the sides from spreading.

The arch was designed to be self supporting without the infill. As long as there is some mortar between the bricks it's still OK and you can repoint the outside of the joints.

If it's all really loose and the bricks can just drop out, it needs rebuilding - don't worry the whole chimney won't collapse - only a triangle of bricks above the arch is supported by the arch. I would expose a bit more.

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