Help - large crack in loft wall

[Glenno]

My house is a redrow 2 story detached built in 1998. I've owned it just over a year. Yesterday while up in the loft i noticed a 7ft long crack extending from just below the roof apex all the way down the internal bock wall to the loft floor. The crack starts from a motar joint at the top and goes roughly vertical, splittiing several blocks on its way down. At its widest, near the top i estimate its roughly 10mm wide. I can get my finger in it.
The room below the crack is the en suite bathroom. Here there is evidence of a small horzonal crack in the plaster to the top left of the window frame (where you would expect the lintle to be). There is no sign of any cracking on the external brick wall.
For the time being, i've glued a ruler across the crack in the loft & marked the wall so i can see if it gets any bigger. Do you think this is settlement, subsidence, or just shrinkage & nothing to worry about?

 

[Glenno]

Here's a photo (if it works)

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• Glenno
• 17 Sep 2014
• 1

 

[Glenno]

This is the same crack lower down

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• Glenno
• 17 Sep 2014
• 1

 

[jeds]

It really is hard to say but (as a surveyor) I've seen dozens and dozens of cracks in aerated block gables just like that in lofts. I've also seen plenty similar - maybe not quite so wide - in brand new aerated block walls just before plasterboard was applied. I sometimes wonder what people would think if they knew just how cracked their houses were under the plasterboard. These never come to anything. It's what aerated concrete blocks do - they crack. However hard you try it when building it is very difficult to prevent any cracks at all. The reason I've seen so many in lofts is simply because the walls are visible.

Having said that, that crack is quite large. So it would be sensible to keep an eye on it. But my gut feeling is it's nothing to worry about.

 

[Nozzle]

I have something similar in our house (built in the 70's) and to assure myself it is not worsening, I've cemented glass slides across it. (you could glue if you can find something that works reliably on brick). It's important the adhesive is not going to give way or flex. The idea is the glass slide breaks if there is a lot of movement, and you don't want flexing glue to compensate for this.

Nozzle

 

[Glenno]

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• Glenno
• 17 Sep 2014
• 1

Thanks for the replies. I've stuck a ruler to one side & a piece of card on the other so i can record any more movement. A hot glue gun works well for this.