cracks in new apartment walls

I bought an apartment about 2 years ago, and have been moved in about 10 Months now. When i did my snag there were several cracks in the walls, two major ones in the parity wall betweeen me and the apartment next to mine, they went from the floor to the ceiling and were about 1mm wide. The builder fixed all of these but warned me they might come back and to be careful with the heating in the apartment for the first few months.

Anyhow about 4 Months ago the major cracks had returned and had opened out again, and the builder came to fix them. He said they shouldn't come back again.

however they are starting to appear again in exactly the same place, along with a few more in the ceiling and other places.

I know that a certain amount of cracks are inevatible, but how long should it take before everything settles down, and should I expect the builder to come back again to fix these, as i am guessing he will probably tell me this time to wait and fill them in myself. They don't bother me too much, but if they open out again to the extent that they were they will look dreadful (one of them is in the main wall in my living room..pretty hard to hide).


Thanks

I would get them investigated by an engineer to see are they symptomatic of something worse to be concerned about. Also you should check if your building is 'homebond', this is a latent defect insurance cover they sometimes get for new homes.

Thanks SeanA

I did query the major cracks with the builder during my snag as to whether they were related to structural issues or not, and I got them to sign a letter stating that they stood over their claim that they were not structural issues. My solicitor advised this as part of the closing procedure.

The apartment is covered by homebond alright.

It does sound like it is more than the normal shrinkage cracks that you would expect.

Why are the cracks coming back and how is the builder repairing them? i.e. if they appear to be increasing in size, I would be somewhat worried - small cracks in the plasterboard are par for the course in many houses and are cosmetic. Your party wall is concrete blockwork and would be loadbearing also, so that continued cracking and increased crack sizes may be hinting at small foundation settlement - not a serious concern if it does not continue, but if it does continue, I would think about getting a professional in to monitor the cracks - you could do it in a crude manner yourself by putting a piece of material across the crack that will not expand or contract (like a piece of glass) mark the crack width on it and take a picture (record the date or even include something in the shot showing the date) and monitor over time - depending on what the foundations are built on, it could take years to fully settle, or months. Has the builder being undertaking any heavy works involving vibrations nearby?

The builder said they were settlement cracks and its to do with joists expanding....they repaired them the last time by opening them out a bit, and replastering. They have just started to re-appear now a few months later, at the moment they are only small hairline cracks, but i am worried as they have already been fixed twice and now they are re-appearing in exactly the same place again but i will monitor them to see if they get as large as they were previously

thanks for the advice