Interior cracks in house - advice please!

[Wizzywoo18]

I own a Victorian 2-bed end terrace house built in the 1880's in London - so clay soil.

Over Christmas, I noticed hairline cracks above the entrance to my kitchen. They are all less than 1mm at present.

Then in the last week, a long crack has appeared in my dining room where the wall meets the ceiling. There's also a small diagonal crack at one end of the wall. The plaster there sounds hollow compared to other areas of the wall nearby. The dining room and kitchen are next door to each other.

A decorator I know took a look yesterday and said take pictures and monitor them over the next 3 months.

Should I contact my insurer now?

What would you do to keep records? I've taken photos and marked the end of the cracks with pencil on the wall, adding the date.

It's never a good time for this to happen but I was desperately hoping to sell this year. The hot summer followed by the cold wet winter worries me as the conditions seem ripe for subsidence.

Thank you.

My advice, based on experience, is not to contact your insurer until you know definitely you need to claim for something. You do not want a subsidence marker placed on your house.

Do what your decorator said. Monitor the cracks.

1-2mm is nothing from a structural point of view. You should only be concerned if they start getting noticeably wider. My house is built on clay and I had cracks appear all over the place not long after I moved in. A structural engineer confirmed that the cracks were due to “seasonal movement” and nothing to worry about. 25 years later they are still there and I’m not worrying about them.

Don’t contact your insurer. Hairline cracks are pretty standard in the type of property you describe. Unless you have a huge tree nearby that roots could be causing issues or adjoining building works (with a PWA in place!) just monitor for now.

Clay soil is a nightmare for movement.
Keep an eye on it, I’d not be worrying about hairline cracks.

Thanks @Elbowpatch, @boulevardofbrokendreamss and @Myfridgeiscool. I will watch and wait ( and try not to catastrophise!!).

This happens in our house whenever we have a really dry summer. I filled them a few years ago (2021) and they came back this year. Along with a lovely new one.

On the news today, 2025 was in the top 3 hottest years since records began!

I’ve been told in the past that anything less than a pound coin width is nothing to worry about