Cracking above wooden window internally (side return, Victorian house)

[Sophie4]

Hello

Looking for some advice please - we are starting to renovate a small room and having taken down some large furniture we can now see there is some cracking above the wooden casement window (diagonally above to the side and above the line of the window on one side).

I would like to repair it and prevent further damage before we have a new window put in, replaster and redecorate.

Any advice on what repair is required would be greatly appreciated. I cannot see any cracking externally and the window fits the full original window area (I suspect the window may not be original and it is not a sash but it is solid wood). Internally, the wall bulges out very slightly above the window and in again before the ceiling height. I believe the bricks above the window externally would have been the original ‘lintel’ but I am no expert.

We are thinking to replace the window also as it is single glazed, an awkward configuration, peeling paint and the window sticks when you try to open it (I favour a wood replacement for the structural benefits although it looks expensive).

Thanks in advance for any advice.

 

[stuart45]

I'd carefully remove the plaster between the cracks to check the condition of the lintel, which is likely to be timber.

 

[Cubist]

It may be my eyes but there appears to be a 'damp' and its position seems to correlate to that of the rainwater gutter and downpipe out doors. Have you checked to ensure that these are unobstructed and not causing rainwater to cascade down again the wall there. As @stuart45 suggests there is likely to be a wooden lintel behind the damaged plaster and that needs to be investigated as he suggests as its not uncommon to find that the ends of a wooden lintel have rotted out and begun to collapse. Any water penetration from outdoors can accelerate that process.

 

[stuart45]

That's a good point noted by cubist about the gutter joint close to the issue.
Best time to check your gutters is when it's hammering down. Most people want to get inside quickly and don't bother looking up. Normally that area of the wall would be reasonably well protected. It can also be the roof leaking a bit at the eaves. If there's felt under the tiles, the first place it usually goes is the eaves. This allows a certain amount of water into the wall. It can be enough to rot the timber without showing up initially in the wall surface.

 

[Sophie4]

Thank you both very much - we will check on both counts, behind the plaster and looking at the guttering when it rains (and in the eaves)

 

[stuart45]

It also looks like your walls were repointed possibly with a sand/cement mix, rather than lime.

 

[Sophie4]

Yes they were (before we moved in)