Interior and exterior building crack

[Strap Flow]

I have noticed that cracks have gradually been appearing throughout my 1960's maisonette since last year. Initially, I thought it's normal wear and tear but to be 100% sure, I got a structural survey done in January this year. Nothing major came up and the surveyor told me that these are normal hairline cracks which usually appear in houses.

Fast forward to yesterday, I was talking with a contractor to fill these cracks properly and paint over them. He noticed that the wall near the entrance door has a crack inside and outside on the same location. The outside crack seems to originate from a boiler flue which was installed in Feb 2019. Photos attached. The crack is staircase shaped and I can also see that one of the bricks is cracked as well. Inside, it seems that the crack has slowly been expanding and one side has risen upwards now.

This is my first house so still learning. Your guidance on the questions below will be very helpful. I'll post this on multiple forums to get as much advice as possible.

Questions:

1. I'm not sure if the outside crack is fresh from the install last year. Do they look fresh? Do they look like they are caused by the flue?

2. I'm planning to recall the structural surveyor to have a look at this again to get a professional view. If this turns out to be a major issue:

a. Is something like this covered under the building insurance? I understand that it depends on the clauses in the insurance but generally, is it covered or will they leave it to me to sort out and pay because it happened potentially due to the boiler flue works I got done?

b. Is there any responsibility on the company which did the boiler flue works considering it's been more than 1.5 years since the work was done?

Thanks.

 

[footprints]

I would say the boiler has nothing to do with it, they have not had to knock a hole just remove the existing tin flue box or an air vent and fill in the hole with some brick any wall should have no failures due to that.
The bond of the brick suggests you have a cavity wall, failing wall ties can cause cracking but normally the cracks tend to be on the horizontal pointing not the perps as in your case.
Unless the cracks almost mirror each other on the inside and outside I doubt it's anything to worry about.
You could fit tell tales across the cracks to monitor the movement, in there most basic form they are slips of glass (like a microscope slide) bonded with epoxy to each side of the crack any movement will break the glass. Or these more sexy ones that measure the movement.
http://www.surveyexpress.co.uk/Insp...MIobO9g_Lb6gIVQbTtCh22VQ9BEAAYASAAEgKqrfD_BwE

 

[Strap Flow]

Thanks Footprints. That's a sigh of relief. Would simple re-pointing fix the outside cracks and how do we go about tackling the cracked brick?

 

[footprints]

Chop out and repair the pointing don't worry about an odd cracked brick my house is built from brittle bricks that crack very easily. I have loads of them, not a problem unless you get a whole line of cracks joined up!

 

[^woody^]

Did you have a proper structural survey/appraisal by a Structural Engineer, or some other sort of survey by a building surveyor?

Stepped cracks like that are typically foundation movement - especially if there is one in the same place on the inside wall. And whilst subsidence is normally covered on home insurance, it has a big excess and taints the house (and future insurance quotes) for years to come.

Widening cracks indicate on-going movement. Whether that's a seasonal thing (there was the hot dry April/May weather which could dry ground), or whether is localised drain or tree root issues, is down to your Structural Engineer to comment on.

You should not do any crack repairs until the cause has been determined and rectified

 

[Strap Flow]

He is a structural engineer although not chartered. Here's his signature text.

BSc(Hons) CEng MICE MIStructE
Chartered Civil and Structural Engineer

Should I check with him again or try to find a Chartered Structural Engineer?

The property is a maisonette above a shop.

 

[footprints]

Does not look too bad to me, 1960's houses are not the high spot of construction. Easy to check with tell tales as I suggested, should you decide to fill the pointing cracks they will soon crack again if you really have a problem.
Worth checking if any major works have been done in the shop below within recent years too though.
If a masionette usually it will be leasehold so should any real problem arise the landlord should be involved.

 

[^woody^]

He is a structural engineer although not chartered. Here's his signature text.

BSc(Hons) CEng MICE MIStructE
Chartered Civil and Structural Engineer

OK then, he seems to be a proper engineer so you could rely on his advice.

If this is above a shop, then presumably its leasehold (unless you own the shop) so the landlord would normally is responsible for the structure.

Has there been any changes to the shop below?