Failing arch lintels on end of terrace

[Victorianhome]

Hi there

I'm a regular reader of this forum, and this is my first post. We've recently bought a Victorian house which needs a lot of work and keen to do things properly, however I'm realising that tradespeople are quick to give me solutions, but they tend to be the ones easiest for them! So keen to get advice from people who also have period properties.

The latest puzzle I have is what to do about 2 failing arched window lintels and the cracking above. The cause of the cracks could be settlement due to the 2 dormer windows (which were done many years ago, and we are just about to have work done to make them more in keeping), or the chimneys which have a lean inwards (though structural surveyor confirmed they don't need rebuilding but we are going to have re-pointed) or a mix of both!

We are going to have the windows refurbished, but as we are just about to have scaffolding put up for the roof work, thought perhaps there is something we should be doing to help the lintels support above (apart from re-point).

Couldn't work out how to upload pics as they seem to be too large so here are links:
https://www.dropbox.com/s/9u7h6mb4o2sk1c2/2017-10-13%2015.10.12.jpg?dl=0
https://www.dropbox.com/s/h5seq3z4kogxcpc/2017-10-13%2015.10.14.jpg?dl=0
https://www.dropbox.com/s/xza932rg32pgd6b/2017-10-15%2010.03.55.jpg?dl=0

Thanks!

 

[88v8]

Hello and welcome.
It's always helpful to edit your profile so it shows your rough location.

Attic conversion, two ugly dormers. Was anything done to the roof structure one wonders.

Failing... I can't see any failure from the pics, other than a little of the mortar having dropped out. That vertical joint between the two archstones is always going to be prone to the mortar dropping out as there's nothing to keep it in there. I hope your window 'refurbishment' - nice original windows - will still allow you to open the windows and lean out and repoint if necessary in future.

The chimneys leaning inwards btw, or sometimes outwards, is a matter of the prevailing wind. I dare say you see it on other houses nearby. Is the wall north facing?
But they are quite sturdy so I wouldn't worry.

What I do see is that the window arches are near the top of the roof, so that makes for an inherent weakness. Not saying it's necessarily a problem.
Our previous house, single upstairs window, the gable end wall - pebbledashed - was cracked from each end of the linlel out to the top of the wall. That was due to differential thermal expansion of the 9x9" concrete lintel and the bricks. We re-rendered, and my remedial measure was to grow ivy over the wall to keep the sun off, thirty years later when we sold, the cracks had not reappeared.
So even if there were cracking, it's not necessarily a big deal.

What I do see that concerns me more, is the pointing. Is this original or has it been repointed? Because in these little pictures it looks like ribbon pointing done in cement, and the stone appears to be eroding. Now I could be offbeam here, but this house would have been built in lime, and if it has been repointed in cement then that is unhelpful.

As regards your dropped mortar in the window arch, I suspect that it is just a maintenance matter. It needs to be carefully repointed in lime (NHL 3.5) with the joints slightly wetted and the mortar rammed in. A small job, but it needs to be done properly by someone who knows how to work in lime.
You may need such a person anyway, in the future.

And I would look at that pointing.

Ivor

 

[Victorianhome]

Hi Ivor

Thanks for your reply, we are based in Yorkshire, not too far from Leeds/Bradford.

I can't see any failure from the pics, other than a little of the mortar having dropped out.
[Jo] Its quite hard to see but the the arch stones on the right seem to be a bit lower than those on the left, I wasn't sure if they would have to remain a perfect arch to support the weight above.

Our refurbishment consists of taking out the plastic windows and refitting with custom made dormers, they will be quite big so we should still be able to access the roof if we need to. We are also putting tiles on the sides/new rubber roof and accoya fascias. I did want sheeps wool insulation put in but the roofer would like to use Celotex instead, internally the dormers are plasterboarded so not sure if it really matters (I've read a lot on this forum about breathability!).

We did have a structural surveyor look at the chimneys when we bought and he said they were within tolerance so I just try not to worry when I look at them!

Regarding the pointing, I'm not sure if it has been repointed. II'd be surprised as very little has been done to the property (apart from the roof), though I'm not 100% sure that the arch window frames are original, so something could have been done around them. I'm getting the chimneys repointed in lime, and I'm going to get the cracks repointed & the lintel. i was just worried in case I'd need some sort of support putting in under them. Happy if mortar can do the job!

If all else fails then I'll grow some ivy ;-)

Thanks again.

 

[MatthewC]

I had a similar issue with a brick arch lintel - see http://houseintheenchantedforest.blogspot.co.uk/2013/08/window-arch-repair.html

I decided (correctly) that this was beyond my capabilities and got a builder friend to do it. It took him about four hours and it was no great hassle for him, using a strong boy to hold things up. He inserted slate in the vertical joints to ensure that the bricks in the arch did not move together again.

Obviously you might have a problem with the use of a strong boy at that height!

Matthew

 

[Flyfisher]

Attic conversion, two ugly dormers. Was anything done to the roof structure one wonders.

I wondered much the same thing. Those arches seem to have very little to actually support, being so close to the top of the gable wall, plus they are well-buttressed by the adjacent chimney stacks, so it would be interesting to know what changes were made to the roof structure to accommodate the conversion (and yes, those sort of 'garden-sheds-on-the-roof' conversions rarely enhance a roof, but hey-ho, it is what it is).

It could well be that a bit of re-pointing work is all that's really needed. At the very least it will tidy up the cracks and make any further movement plainly visible, at best it will tidy up the cracks and they'll not return at all.