Cracks in walls

[bigkriss]

Hi,
i am building a small kitchen extension.While removing some render from an existing wall I noticed two vertical cracks, about two meters apart. One crack is about 2mm across and extends upwards from the top of the DPC about two meters.The wall is solid block and was originally a single storey extension, subsequently built on to give an upper floor. (planning and building regs obtained and approved)The crack does not extend below the DPC to the brickwork below. Is this something I should investigate further? should I repair the cracks?
Thanks to all for any help/comments.

 

[Ossy]

Can you take some pictures for us to have a look at?

From what you're describing there shouldn't be too much to worry about. If there weren't any signs of cracking in the render/internal plaster then it doesn't sound like there's anything major going on. How long ago was the additional storey added? Without any more details it's not possible to be certain what's really going on.

I'd probably patch them up and keep an eye on the area in question to see if anything else transpires. If you're worried or want some guarantees, call out an Engineer. They might charge you £150-200 to have a look and write a quick report/letter, but it'll give you some peace of mind.