Cracks in wall - can I repair these myself?

[NT88]

2 1/2 years ago we had a 11m x 2m singe story extension built, but around a year ago I noticed a vertical crack and now there are 2 cracks. The widest is 2m from one end of the extension wall and the lesser crack is 3m from the other end. The extension is split into 2 rooms - 9m x 2m + 2m x 2m. I enclose 3 photos, the battery is an AA size next to the widest crack for scale purposes.

Untitled

• NT88
• 19 Apr 2011
• 1

Untitled

• NT88
• 19 Apr 2011
• 1

Untitled

• NT88
• 19 Apr 2011
• 1

I have spoken to the builder about this matter but he said it was my fault for painting the walls too soon after the build was completed.

I was thinking of filling the cracks and painting, but a friend has told me the crack would just come back. He is a very good DIYer and got me to take the pictures I have posted. He pointed out that outside there is a 'movement joint' halfway along the brick wall that has come apart slightly at the top, and he suspects there are 2 more movement joints on the inside leaf of the wall which are made from grey blocks.

He went onto say the grey blocks have probably shrunk and the 1st movement joint perhaps should have been incorporated at the extension internal wall junction and the 2nd joint disguised by a dummy structure on the wall and ceiling half way along the 9m run of the longer extension room.

He did remind me however that he is not a builder but suggested I ask for opinions on this forum.

So can I mend this with DIY and is it all my fault as my builder has stated?

Or is my friend right and can I DIY a fix in that case?

 

[joinerjohn]

I see on the second photo that the coving has cracked as well as the plaster. What type of coving was put up? It's either something like Gyproc plaster coving or one of those foam filled lightweight type. If it's the plaster coving, I'd be worried that this has cracked. Perhaps time to get another builder or surveyor in to advise. As for your original builder saying that you painted the walls too soon after completion,, I've never heard of this causing cracks as straight as those .

 

[jeds]

11m long is enough to allow significant expansion and contraction. Sounds like your extension was designed for this externally but not internally. I would check back with your drawings and specification first of all to make sure there wasn't an expansion joint somewhere in the plaster that was omitted by your builder.The cracks are most likely cosmetic (i.e. due to lack of expansion joint) so I wouldn't get over concerned at this stage.

PS. Painting has nothing to do with it.

 

[Richard C]

Agree with jeds regarding the expansion joints; there may be corresponding expansion joints on the internal walls but if they have just been plastered or boarded over & then skimmed then it will crack. No amount of filler or even lath/strapping repair will stop it reappearing with seasonal temperature/humidity changes & flexible expansion joints will be needed on a 11m run of wall. Probably not serious but keep an eye out to see if cracks start appearing elsewhere.

Your builder is talking a load of old cock regarding painting too soon; it will neither have caused or stopped that.

 

[NT88]

Thank you for the replies so far. Just to be clear the outside brick wall is split into 2 walls by the brown mastic joint so there are kind of 2 x 5.5m walls if that makes sence.?

 

[^woody^]

It's not clear where this joint is, and that will determine the type and function of it - ie a movement joint for the extension, or an expansion joint for the wall

By the looks of the cracks in the coving and ceiling, you have some movement (and not just contraction of the wall) - which you will have to monitor to see if its normal or not

Your friend is correct in that these cracks will tend to crack again if you just fill them

 

[wavetrain]

NT88 can you take a more-in-focus photo showing the cracks near the ceiling please?

 

[NT88]

I will sort the photos tomorrow.

 

[jeds]

Subsidence or settlement would be indicated by some rotational movement. That's to say the crack would be wider at one end than the other. Are your cracks wider at one end or are they parallel?

Did you check drawings for an internal expansion joint?

 

[NT88]

Thank you again to those who have responded to my forum posts.

I have now looked at the plans. After I have chatted to my friend this evening, I will post again with details of the plans and answers to "jeds" last post.

 

[NT88]

Untitled

• NT88
• 22 Apr 2011
• 1

The plans do not have movement or expansion joints marked. But on the right hand side of the A3 sheet there is a column titled 'General Specification', and half way down is the following printed:


Movement Joints

Provide movement joint in lightweight blockwork @ 6m centres max. Joints to be tied together with 40mm x 1.5mm galvanised steel strip 200mm long in alternative courses. Provide mastic pointing externally.





My friend looked at the plans with me and voiced the opinion that drawings showing minimum detail was not uncommon.

In answer to jeds question about the width of the crack - The 2 cracks are covered in places by very hard to move furniture so I cannot see their entire runs, but I believe the main cracks are constant width along their respective runs.

So who does the forum believe is at fault?

1) the Architect for not specifying where the joints should be and also not specifying the ceiling should also have been broken and a dummy beam constructed to hide the ceiling gap?

2) the builder for not building the expansion gaps with the above extras but instead just plastering over them?

3) Me for not employing a project manager to have overseen the work?

Happy Easter to you all!

 

[freddiemercurystwin]

Oh FFS, there just some hairline cracks, you get them in any new construction, besides the architect specified them, the builder didn't install them properly, you're just wasting energy, fill them up with some Polyfiller and move on with your life. Jeez!

 

[^woody^]

LOL , is it hot and irritable down in sunny Devon, FMT?

 

[wavetrain]

FMT the OP has some photos at the beginning of his post with an AA battery for scale. That is not a hairline crack.

Anyway Mr woody has already advised the OP that the cracks would most likely come back if he just filled them.


FAO of NT88
I think FMT is in one of his moods... again. And on Good Friday as well!! I also think it would be worth speaking to your architect to see if he or she can come up with a permanent solution.

Is he/she based in Devon?

 

[freddiemercurystwin]

OK, its hardly brain surgery, the solution is to ensure the external movement joint goes all the way through from outside to the inside.

So, hack off plaster internally, determine if a MJ has been installed in the inner skin. If not it needs to be retrospectively installed. Once that's done a new MJ can be applied in the plaster internally. Re-plaster up to MJ and repaint. Then fill his cracks with some polyfiller and repaint.

Let me guess, is the OP gonna bother doing all that?

Or is he gonna make idle threats on a Forum about suing the architect or the builder which will never amount to anything anyway. Who was inspecting the works as they proceed on site? Oh oh, what's that I hear, do I hear someone mutter that no-one was overseeing it?

Or could the OP just slap some Polyfiller in the gap and repaint and shock horror maybe do it every couple of years? Freekin hell, half the cracks are obscured by furniture anyway!

@wavetrain, oh I can't even be bothered to respond to your inane drivel.

Jeez!