Blown plaster/cracked brick work?

[shadyron]

Hey there,

I'm visiting my parents' place at the moment and noticed a crack in the plasterwork in one of the bedrooms. It runs from under the window in there all the way to the floor. It's vertical (at 90 deg to the window), but does go horizontal for a short distance. Very much like this:

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Anyway. It's not diagonal. Knocking on the plaster to the left of it sounds solid. Immediately to the right is hollow. 6 inches to the right again and it sounds solid again.

I've had a look at the external wall, which is brick, and the row of bricks under the window itself is fine, but the join to the row of bricks under that does look to be cracked, quite considerably. To my very untrained mind, the symptoms would suggest that damp has been getting in there and has at least blown the plaster, if not caused some more serious damage. That the crack is running the full height of that wall suggests that it's pretty bad already. Would that seem a reasonable consensus? I know that without some more information/pictures/investigation it's really quite difficult to tell, but I'm trying to add some weight to my assertion that they really need to get someone in to sort this rather than just leaving it be.

I can't see that it's a simple plaster crack as the house is approximately 35 years old now, and hasn't had any work done on it in quite some time. The last thing that was done was the windows being replaced approximately 8 years ago.

Many thanks, as ever, for any assistance you're able to provide.

 

[PrenticeBoyofDerry]

Some pictures would be appreciated.
Most properties suffer from settlement issues which can cause cracks within plaster and mortar joints to crack, even sometimes the brickwork can break.

Do your parents know if these cracks are historical or if they have only just appeared.
Any ingress of water can only increase damage to plaster.
Back in the day, window boards were fitted to wooden stakes driven into the wall, in a vertical direction, I have come across many of these being responsible for internal vertical cracks beneath windows.