Cracks on exterior wall

[Stephanie]

Hello,

I found this forum online and was hoping that I would be able to ask for some advice about a property we have moved into earlier this year. A few days ago I noticed a crack running down the exterior wall where the bay window meets the wall (see images below). I am unsure as to whether this has happened recently or if it has been there for a long time but it is a rather long crack and I do worry about it.

Having had a look at neighbouring properties I saw one other building that had a very similar crack. As seen in the pictures, there is also a smaller crack on the bay window's structure. My question now is whether this is something period properties like the one we live in sometimes have but don't need (much) work done to, or whether this could be something more serious. The property was built sometime in the 1860s or 70s.

The home report we received before buying the property had a score of 1 for the building exterior and no issues were highlighted there. However, the same report also gave the condition of the roof a score 1 but we recently had a leak and now need to get new zinc work around our upstairs neighbours' dormers. In other words, I do not believe that this was the most thorough of home reports.

If you could advise on this issue, it would be greatly appreciated.

Many thanks,

Stephanie

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[MatthewC]

Hi Stephanie

Welcome to the forum, and well done for posting meaningful photos on your first post - how to do that does sometimes baffle lots of people. It's a nice looking house - are you somewhere in the north? I think you have two different issues:

Firstly, the join between the wall and the window looks like it has been repointed with cement, not lime mortar. You can prove this by putting a little bit of the mortar in vinegar - it will fizz if it's lime. I'm not sure whether your pink stone is limestone or sandstone, but both of these expand and contract, as well as being porous. However, if (as lots of tradesmen do) it has been repointed with cement, that is effectively rigid and so does not expand and contract; the eventual inevitable result is a crack and loose pointing (if it's not very deep), which seems to be what you have. The cure is to remove the pointing and repoint with lime mortar i.e. lime putty or Natural Hydraulic Lime (NHL). If you have dampness inside it could be caused by this crack.

Secondly, I think the crack in the stone mullion was caused by the original workmen! What they should have done is to lay the stone "in its natural bed" - it was formed as horizontal layers and should be used in the same way so that the compression is following the natural line. However it looks as though they have done it more cheaply by just turning the stone through 90 degrees, with the natural strata running vertically. I'm not sure what can be done about that other than replace the stone when it gets too bad, but if it's taken 150 years to get to that state then it should last a bit longer yet! We just replaced some like it on our church and they were far worse than yours (if that's any comfort).

Best wishes

Matthew

 

[bobby spray]

Hi Stephanie. i have a building of very similar construction to yours. Your cracks are nothing to worry about. Very typical of a building of this age and constriction and i have seen a lot worse. Unless it's causing you a problem - like letting in water, I honestly wouldn't worry about it. if we are playing guess the area I would say northern too, Scotland - possibly central belt?

 

[noj]

Welcome!

Removing the cracked pointing next to the stone and re-filling with burnt sand mastic may be a good solution?

 

[plasticpigeon]

That is a lovely bay window on what I imagine is a very sturdy and attractive property.The small crack wouldn't worry me at all. Removing whatever is in the gap may cause more damage and problems that it solves. If it is cement and has been done recently and the stone starts to erode in an accelerated fashion or has been said, water is getting in, then it may be worth taking out but otherwise I'm sure it will be fine.

 

[Stephanie]

Thank you all very much for your replies, your advice is very helpful and I'm glad to hear that you do not believe it to be a serious issue with the structure of the property. Unfortunately, my knowledge about period properties is rather limited (I will work on that!) and I am very glad to have found this forum.

I'm also very impressed with your guesses about where the property is located (it's in Edinburgh) - may I ask what feature gave that away?

Matthew, thank you for the well-explained and informative response. I was surprised to read that the crack could have been caused by the position of the stone. I will keep an eye on it, just in case if it gets any bigger. And you are right in saying that the stone is very porous, on one side of the bay window it shows quite a few fairly deep cracks and looks very weathered. Would you have a tip on how that could be patched up - or is it better left alone?

Again, thank you all for the warm welcome and the kind responses!

 

[88v8]

Agree the crack between bay and ashlar is not really an issue and could just be raked out and refilled.

The crack in the mullion however, I see it continues in the cill stone, so it's not just a matter of the stone having been mis-bedded. I wonder if there's an iron dowel in there which is rusting. In which case it will get gradually worse until the face blows off. At that point you will need a stonemason.
But not yet. Not yet.

Ivor

 

[bobby spray]

Hi Stephanie, Sandstone can weather quite badly if the end grain is exposed to the prevailing weather. The conventional wisdom is to leave well alone unless it's causing you issues. patching of sandstone is normally done with a conservation mortar such as Lithomex. It's a pretty easy DIY job for simple geometries and is available from masons mortar in Salamander street, Leith. If that seems too difficult (access could be a problem) that there seem to be a few stone masons in Edinburgh specializing in Lithomex repairs.

Nothing in particular gave the location of your property away, However the style, construction and materials all point to Central Scotland, however in retrospect I should have narrowed it down even more, it was unlikely to be Glasgow as the sandstone there is redder.
The only advice I'd give you with that style of property is to keep the parapet gutter clean.

good Luck

 

[Stephanie]

In which case it will get gradually worse until the face blows off. At that point you will need a stonemason.

That doesn't sound very good but I take it it would be best left alone and monitored for now?

Bobby spray, thank you for the advise, I also thought leaving it alone for now might be best. The cracks look fairly deep but overall it doesn't look like it will crumble away anytime soon. As for the parapet gutter, we've had some issues with the roof recently and need to get the water gates around the dormers replaced. When the roofer was up there I had a look down the slope of the roof and there does seem to be quite a bit of vegetation in the gutter. I will make sure to mention that to them when they start their work.

Thanks,

Stephanie