Question for the DIY experts

Afternoon all.

I've had a large crack (expansion crack apparently) appear in the hallway of the flat from ceiling to floor. I got quoted a fair old sum which I don't have spare and so I'm thinking of sorting it myself. I assume Filler, sandpaper, paint (in that order) would do the job but I genuinely have never done any decoration before. Plaster walls btw

Some pics of the crack - based on what you see is it feasible that a newbie could get this sorted without major fuss?https://uploads.tapatalk-cdn.com/202...6918c28cd0.jpghttps://uploads.tapatalk-cdn.com/202...68da40c7ab.jpghttps://uploads.tapatalk-cdn.com/202...1860c4f8ef.jpg

Easy DIY job.

Rake it out with a screwdriver or chisel, fill it, sand it and then paint it

You live in a new flat - i would be asking those above and below if they have similar. You need to ascertain if a structural issue. Are you still under 10 year NHBC warranty ?


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Does the crack go all of the way through to the other side of the wall?

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Originally Posted by dandanthewatchman

You live in a new flat - i would be asking those above and below if they have similar. You need to ascertain if a structural issue. Are you still under 10 year NHBC warranty ?


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Originally Posted by adrianw

Does the crack go all of the way through to the other side of the wall?

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Yes, not necessarily straightforward. I’d be asking the managing agents to investigate as it may be a structural issues that they would need to deal with (and possibly a buildings insurance matter).

That looks rather large as an expansion / contraction crack. New builds all my life and only had really small ones that wouldn’t even need filling.

As Tony says, start talking to neighbours and understand the scale of it. I’ve only ever seen a couple of mm at most and not the entire height of wall.

Quote:

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Originally Posted by dandanthewatchman

You live in a new flat - i would be asking those above and below if they have similar. You need to ascertain if a structural issue. Are you still under 10 year NHBC warranty ?


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Yeah I asked and they said whilst warranty still exists (until December this year) cracks like this aren't covered under warranty as they are due to expansion of the plaster. Apparently this has been the case with some other flats in the block as well

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Originally Posted by adrianw

Does the crack go all of the way through to the other side of the wall?

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No just on one wall

As above.

The raking out (i.e. enlarging the crack by scraping one of the tools described above) is important. Sounds a bit counter intuitive but it gets rid of all of the loose bits of plaster and gives a firm substrate to put the filler in. It is also a lot easier than trying to squeeze filler into a thin crack. Make sure you dust it with a dry brush (not the one you will paint with) to remove the last crumbs and bits of dust.

You might want to apply a mesh first which will reduce the risk of it re-appearing but it is an extra faff. Alternatively do it without the mesh and then, if it does reappear, try again with mesh.

I've found that fillers are a bit of an annoyance. I haven't found one yet that doesn't shrink on even the smallest of cracks (perhaps I am doing something wrong) so a second or third application maybe necessary to get a nice flat finish.

I see that others have already suggested finding out a bit more about the causes.

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Originally Posted by learningtofly

Yes, not necessarily straightforward. I’d be asking the managing agents to investigate as it may be a structural issues that they would need to deal with (and possibly a buildings insurance matter).

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Thanks Tony, they fobbed me off saying the surveyor investigated similar cracks in other flats and determined they weren't structural, I have insisted in an investigation on mine.

Cheers

Ryan

Get someone in rather than do it badly and then have to stand there shuffling your feet when you inevitably get someone in to do it properly. That’s my approach anyway!

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Originally Posted by Wimm

As above.

The raking out (i.e. enlarging the crack by scraping one of the tools described above) is important. Sounds a bit counter intuitive but it gets rid of all of the loose bits of plaster and gives a firm substrate to put the filler in. It is also a lot easier than trying to squeeze filler into a thin crack. Make sure you dust it with a dry brush (not the one you will paint with) to remove the last crumbs and bits of dust.

You might want to apply a mesh first which will reduce the risk of it re-appearing but it is an extra faff. Alternatively do it without the mesh and then, if it does reappear, try again with mesh.

I've found that fillers are a bit of an annoyance. I haven't found one yet that doesn't shrink on even the smallest of cracks (perhaps I am doing something wrong) so a second or third application maybe necessary to get a nice flat finish.

I see that others have already suggested finding out a bit more about the causes.

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I was taught that if it cracked I was using it to thickly, better applying thin layers

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Originally Posted by ryanb741

Yeah I asked and they said whilst warranty still exists (until December this year) cracks like this aren't covered under warranty as they are due to expansion of the plaster. Apparently this has been the case with some other flats in the block as well

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No just on one wall

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I would send a notification to the warranty people come what may. They may well send someone to investigate. You can’t risk the policy running out.

I’d also get my own surveyor in to have a look. Sounds strange for this to happen 9 years after construction.


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I’m no expert, but that is a very straight crack and looks to be along the line of plasterboard.

Is it a solid brick/concrete block wall or just a stud wall?

If you’re going to fill it, use Toupret interior filler. You can get it from Toolstation and it doesn’t shrink or show through once painted. Fantastic stuff & easy to use.


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Remove all loose plaster. Use some plaster scrim to tape over the crack. Use some easy-fill plaster. Put on thin coats. When one coat is dry sand down with 120 grit (Only remove any high spots) Apply another coat, same again. If needed another coat and when dry rub down and blend in the plaster to the existing wall until flat.

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Originally Posted by ryanb741

Thanks Tony, they fobbed me off saying the surveyor investigated similar cracks in other flats and determined they weren't structural, I have insisted in an investigation on mine.

Cheers

Ryan

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Ask for a copy of the surveyor’s reports.

Looks more than expansion to me.

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Originally Posted by dandanthewatchman

I would send a notification to the warranty people come what may. They may well send someone to investigate. You can’t risk the policy running out.

I’d also get my own surveyor in to have a look. Sounds strange for this to happen 9 years after construction.


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I agree it’s unusual for such a large crack to appear so long after completion.
I would get a surveyor in and notify the warranty firm / managing agent just in case

Is that an external wall?

What does the other side look like?

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Originally Posted by adrianw

I was taught that if it cracked I was using it to thickly, better applying thin layers

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It doesn't crack but it shrinks to form a small concave cavity in the middle of the filled portion. Even on filling cracks 2mm deep.

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Originally Posted by Wimm

It doesn't crack but it shrinks to form a small concave cavity in the middle of the filled portion. Even on filling cracks 2mm deep.

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Have you tried the ready mixed Easyfill for cosmetic stuff, it’s very good, I’ve filled and taped and jointed with it, seems to just work

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Originally Posted by adrianw

Have you tried the ready mixed Easyfill for cosmetic stuff, it’s very good, I’ve filled and taped and jointed with it, seems to just work

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Ahhh, that rings a bell. A decorator we used a few years ago left me half a box of un mixed filler as he swore by it. The box nover reappeared after a move and I couldn't remember the name. I think that was it.

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Originally Posted by Sinnlover

I agree it’s unusual for such a large crack to appear so long after completion.
I would get a surveyor in and notify the warranty firm / managing agent just in case

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+1

An expansion crack is not an explanation I would be prepared to accept so long after build completion.

I echo what others have said and would maybe even instruct your own structural engineer for an independent opinion, for complete peace of mind.

If it turn's out so be something more serious at least you would have it identified before warranty lapses, the engineer costs would be a small price to pay.

Is it plastered masonry or skimmed plasterboard? The thin delamination at the top suggests the latter but you say it’s a plastered wall which suggests the former. It would be pretty easy to rake out the crack and fill it but I’d want to know if there is a problem with the substrate or if some numpty has plastered over an expansion joint in the block work substrate.

Rake it out, if it’s blown then PVA to help hold the edges then Toupret flexible filler but not overfilled as it’s not easy to sand, then over fill with normal filler sand and paint.
Let the flexible filler cure for 24hrs.