Crack in brickwork above oak mantle

[mellor5333]

Cracks have started to appear above oak mantle due to the wood shrinking over the last 6 yesrs since installation. It sits on a metal “shelf” as shown on the photos. The gap between the oak mantle and first layer of cement has increased over time as the wood has dried out and shrunk.
Is it just a matter of pushing cement into the gap to the width and length of the beam ? Obviously I would have to try and match up pointing colour to existing. Many thanks for any comments/help.

 

[manchestermonkey]

Assuming that the steel lintel beam is adequate, you could do with filling the gap with something more substantial than a simple mortar, such as epoxy resin which can be injected into the gap. At the moment, the masonry is trying to arch over the gap

 

[^woody^]

Knock some slate in to wedge the bricks back up, then point.

 

[manchestermonkey]

Or as Woody said, slate packing and repoint

 

[George_engineer]

Was the lintel installed at the level shown in the construction picture? Going by the supporting brickwork, that is underneath the timber mantlepiece.

Does that mean the timber is sat on the lintel and the brickwork is built off the top of the timber? If that is the case, then as the timber has shrunk, the brickwork above isn't directly supported and so has cracked.

The lintel should have been placed above the timber to directly support the brickwork and the timber would have been fine self-supporting.

 

[mellor5333]

Yes, the metal ‘L’ shaped lintel is installed as shown in the pic with the oak timber sat on it. The brickwork is built on top of the timber and over the 6 years a gap has formed due to shrinkage of the wood.
I will try and insert some thin slate and somehow push in some cement as far as I can.
Or maybe inject gripfill or similar then point over, although nozzle will not fit into the gap that far.

 

[robinbanks]

A mortar gun may make the job easier for you to get mortar squirted in further back. Also, I find tile adhesive works quite well in the guns due to its smooth-but-not-watery consistency when mixed to spec. For color consistency with the rest of the brickwork you may want to point the face with a mortar mixed to the same ratio as was done originally, if you can find sand and cement that are similarly colored to the originals..

If you've no idea on the kind/color of sand/cement, perhaps consider mixing a few different batches of mortar and/or dye and let it dry to see the final color then you can get a reasonable match. Probably goes without saying but make sure you keep note of what ratios you mixed; I write on a scrap of plasterboard and put a dollop of mortar above it

 

[George_engineer]

Yes, the metal ‘L’ shaped lintel is installed as shown in the pic with the oak timber sat on it. The brickwork is built on top of the timber and over the 6 years a gap has formed due to shrinkage of the wood.
I will try and insert some thin slate and somehow push in some cement as far as I can.
Or maybe inject gripfill or similar then point over, although nozzle will not fit into the gap that far.

Slate is the best way. This is because you'll be able to tap it in and 'jack up' the cracked brickwork and ensure load transfer.

Gripfill won't do that

 

[mellor5333]

Apologies, there are concrete lintels installed as shown.