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How do i repair a crack in my sitting room ceiling that was badly filled in?

A hairline crack appeared in our newly skimmed ceiling running from one end to the other. My other half tried to apply a polyfilla to fix it but it was too thick and now it looks worse now than before as it's raised like a bumpy line running through a smooth ceiling.What's the best way to fix this? Does it need to be all cut out and reskimmed? Is it a simple job to fix by a plasterer? Will it be messy to fix?

2 Answers from MyBuilder Plasterers

Best Answer

if its simply been filled with polyfilla then it should be easily sanded down to a smooth finish. Use a fine 150 or 180 grit sand paper that will do the job but it will be dusty.
If the crack was a straight line from one end to the other then it sounds like its where the plaster boards are joined and it could be to do with the with slight movements on the joists from walking about in the room above.

Hope that helps.


Answered 26th Sep 2012

Hi it's Danny from DW Plastering , yes you'd think that poly filler as it is designed for sanding would be quite easy to blend! Trouble is if too much poly filler is applied, it can be quite tricky to get that perfect seem less finish, this is why for quite the opposite reason, plaster or (skim) is not meant to be used as a filler and is designed for larger areas as it is not designed to blend to achieve a seem less finish!

This requires the know how of a good plasterer if a filler is not required, I'm really not sure on how bad or thick the bump is, but you could try a flat vibrating sander applied with even pressure, but I really would take it easy and use a very fine sand paper with it and not too abrasive. The fine paper will have a tendency to clog up quite quickly but with a regular shake out or a beat you should be fine ( better safe than sorry).

If the crack reappears and you have reason to believe that it is the movement between two plaster boards that may have caused it in the first place, I'd suggest trying to re screw close either side of the crack along the length of it, one screw either side about 12 inches apart. This may tighten the boards and stop the movement that caused the crack! Counter sink the screws slightly but be careful when doing so as you don't want to go straight through the board and end up with holes too! Then simply apply a small even spot of filler over the screw heads and once dried sand flush. Good luck😊


Answered 27th Feb 2014

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