Is this diagonal crack worrying?

Question

Have a relatively new 5 year old double storey townhouse. There is a long diagonal slightly jagged crack extending from the corner where the door meets the wall in the ground floor. It's almost 60cm and probably extended 30cm over the last few months. The base of the crack seems to have gotten bigger, maybe 5mm wide. The builder is insisting this is just settlement of the house but it seems more worrying to me. Pretty worried about the structural integrity of the house now. Do you guys think this warrants further investigation by a structural engineer or someone?

Answer 1

It's a bit difficult to tell since your photo has no context. But generally cracks in drywall, especially at the joints, are common and nothing to worry about.

In this case, however, there is clearly something going on behind the drywall that has cracked it and it does not, to me at least, look routine. This is especially true as you indicate that the crack is still forming.

I'd be looking at what's under the floor near this wall. Is the foundation subsiding? Was the home improperly supported to begin with?

Answer 2

I'd be more worried about the lintel and/or its supports by the door's top corner.

I'm here in Ireland, so if it was an old stone/block/mass-concrete house I'd say that the timber lintels were sagging. But as it's a new one, this should not be the case as lintels for traditional masonry walled houses have for many decades have been steel reinforced concrete and should neither crack not sag. With new timber-frame houses, it's a sort of timber stressed-ends beam lintel with the bulk of the stress borne at the upper and lower end of the beam.

Yet, wherever you are and whatever the way the house is built, something is out of line when a crack like that opens up. So call a building surveyor or structural engineer in immediately. They may well be able to deduce that the underlying problem has been there from the outset. In other words, it's a build quality issue and compensable if the builder is still in business.

So call the surveyor/structural engineer today.