How to repair cracks in ceiling and cornice?

[unawarek]

Hi, 

We've had some cracks appear over the last 3 years since we moved into our house (brick veneer house on a slab, the cracks weren't there when we first shifted in), and was wondering what the best way to repair these were. The cracks are mostly on the (plaster) ceiling and on/around the cornice, and don't spread down the walls.

Community manager's note: Check out How to repair a cracked cornice for expert advice.

Can I just use a multipurpose filler to go over the cracks, or would I need to do more (scrape out cracks, use mesh tape)? Thanks!

    

[EricL]

Hi @unawarek

Thanks for sharing that question about repairing the cracks in your ceiling. Your suggestion of using a multipurpose filler is right on the money. I suggest using some 240 grit sandpaper on the cracks to smoothen them out. Once you've removed all the loose material, make sure to give it a good clean wipe with a clean rag before using the filler.

Make sure to give the filler enough time to fully cure before repainting the damaged area. I suggest using British Paints 100ml White Prep 4 In 1 Water Based Primer Sealer Undercoat before applying your ceiling top coat.

Here is a handy step-by-step guide: How to repair cracks in plaster

If you have any other questions we can help with, please let us know.

Eric

[TedBear]

Hi @unawarek , I find that thin cracks can reappear if you just put filler over them. It is best to run the corner of a metal scraper along the cracks to open them up a little to a V shape. That way the filler has more surface to attach to and won't just fall off, as it does when it's put on too thin. Sand them first, as Eric has said, to get a level surface to work with. 

[unawarek]

Thanks for the tips @EricL and @TedBear 

I was looking at this multipurpose filler: 

https://www.bunnings.com.au/uni-pro-500g-multi-purpose-interior-filler_p1210281

And it states to not use for areas where structural movement occurs - I've always suspected the cracks appeared due to some minor movements of the house ever since we moved in. If so, would something like Selleys No More Gaps be better to use, as it says its designed to cope with building movement?

If so, would I just squeeze it out over the cracks and go over it with a putty knife to smooth it over? Thanks!

[TedBear]

Hi @unawarek 

That filler (No More Gaps) is best for corners and joins (gaps) between different types of surfaces. I don't think it will blend in to a flat surface. If you want something pre- mixed you could use this product:-  (comes in a smaller size too)

https://www.bunnings.com.au/poly-1-2kg-interior-small-cracks-filler_p121037

Please don't wipe anything over the fine cracks before scoring a small gouge along them first, (ie make them a deeper crack) otherwise it will fall off at first sign of movement. Even just applying paint can pull off thinly applied filler.

[EricL]

Hi @unawarek 

Good spotting on the possibility of continuous movement of the house. If that's the case I suggest using Selleys 475g No More Gaps Interior Multipurpose Gap Filler in combination with Pro Renovator 38mm Plastic Scraper. Please keep in mind that this particular filler is difficult to sand down so I recommend making sure to scrape off as much of the excess filler as you can and try to keep it as flat as possible.

If you need further assistance, please let us know.

Eric