Hairline cracks in new plaster skim

ashe

We're in the middle of redecorating our living room, and as we had a window enlarged to twice its size & removed a fireplace, we were going to have to get some plaster work done anyway so decided to just re-skim both those walls. The rest of the walls in the room we just left as they were. Once the plaster had fully dried and been left for a few days, we gave it a mist coat and then 2 days later it was given 2 standard coats of paint.

The plastering job was not great, and we had to do a load of DIY sanding and filling work to get anywhere near an acceptable look - it largely looked fine as skim but once the paint went on it really highlighted all the bad parts, especially around sockets. Thankfully thats largely sorted out now, but in two points we've got issues with hairline cracks - one is behind where the fireplace was, which I am guessing he has put plasterboard up, and one is above and below where a new socket was added (not by the plasterer). There were no cracks in the previous plaster.

They're only really fine, and from googling this can happen as fresh skim settles/dries - especially with the weather being sweltering when the work was done (was that really really hot week a few weeks back) but as the plasterer was pure crap I really don't want to get him in to fix his work (he came back to redo the sockets and basically put caulk around them meaning we had to strip it off, build up the plaster behind the sockets and then sand down and finish, as he had done a horrific job with them plastering right up to the sockets even though they were loose, so they wouldn't go flat)

I'm happy to have a go at sorting it, but with having paid for plastering and painting, I don't want it to look like an obvious fix. I've got some Gyproc Easifill - would I just scrape some over, flatten and sand down then repaint? or use stanley knife to enlarge and then fill/sand/repaint? or is it advisable to use fibreglass tape? Have used fibreglass tape before but feel you can usually see where this has been applied because its got a level of thickness to it and sanding it down can sometimes get to the tape, making it visible. If it ends up with a slight bump it will look terrible because its sidelit by the new large window, and we have hue light strips behind our TV so if they're on they side light it from the other direction.

Failing that I can get someone in to try fix it, but rather have a go at doing it myself if can get the correct technique to keep it flat?

Mistral001

Such cracks are generally ignored and filled during normal cyclic painting, but if you cannot wait until your next redecoration, fill them with Polyfilla and paint over. If you use the same paint as the decorator used, you should be able to paint over locally without it being noticed. You can choose to rake out the cracks before filling but it is not absolutely necessary.

ashe

Yeah we still have the paint and touch ups are fine as we’ve done loads to fix the plasters scrapes and scuffs and sanding around sockets etc

Just didn’t know if needed to use just filler or the tape, rather use filler as feel like will be able to see fibre glass tape

Thanks for confirming 👍🏼

TELLIT01

Trying to fill hairline cracks can create more problems than it solves. Generally simply painting over them will be enough, as the paint will fill the crack.

Grenage

If you do fill the cracks, I've personally had little success in filling without raking out a bit more plaster first.

Sometimes paint will fill a hairline crack, but it will reappear more often than not.