What kind of professional needed to look at cracks?

[MrsAlwaysRight]

Over the last approx 6-8 months we've started noticing small cracks appearing on the walls in various rooms. They are predominantly narrow vertical cracks and are in various places but many are above and below windows. No external cracks.

What kind of professional would be best to get in to check what might be causing this?

Has anyone else had this happen? No recent building work on house. Extension many years ago and loft done several years prior to this occuring. House is built on clay.

Thanks in advance

Clay is notorious for shrinking and expanding with the weather but settlement should be finished if the last works were years ago. If you’re concerned a builder will be able to tell you what’s what. Personally I’d fill them and see if they opened again, if they do get a trade opinion.

Agree I'd monitor it and if they reappear and get larger then a structural engineer may help.

I would be less tempted to ask a builder who has a vested interest in finding faults. I would want to consult a structural engineer who can be objective and has the right qualifications. Builders can vary massively in expertise and trustworthyiness.

You want a chartered building surveyor. Take a look on the RICS website for accredited surveyors.

Thanks for the replies

Are there large trees nearby? Within say 20 meters. Large trees on clay soil can cause subsidence (roots can be twice the aize of tree and go under house foundations and cause shrinkage when looking for water).

Definitely not a builder, they may be able to make good the cracks but can not advise on cause. A chartered surveyor (unless they have an engineering background) would probably recommend an engineers report is anyway. If they are currently fine cracks and not external as PP said, I would probably monitor and if the cracks get bigger or more appear then approach a structural engineer. Keeping a record of locations and widths of cracks may assist any future engineers investigation.

Vertical or horizontal hairline cracks internally are often just plaster crack, and nothing to worry about. Any diagonal or zig-zag cracking is a red flag. Do get it checked out though, if you are worried.

Building surveyor will inspect and monitor. They'll bring in someone structural if needed.

I'd go for RICS surveyor who will advise if structural is needed. Vertical settlement cracks are very normal. Have a look at RICS find a surveyor website.