crack in wall outside and inside - advice?

Doozergirl

wallofbeans wrote: »

Shoe? Does that mean the end of the open pipe? The larger one? That is coming down from the roof gutters. The thinner pipe is from the kitchen and goes directly into a second drain that is further along.

No sign of damp inside and drains and area around dry as a bone.

Yes. Looking again, it's not facing the house and there's a slant down away from the house, but vast amounts of water flow down those pipes and so it's far better that they go directly into the gullies. It stops any potential escape of water to the ground, rather than the drains, and the gully can't get blocked by leaves and detritus.

The positioning of the sink waste and decking joists is bad. I understand that the sewer is probably further away than the storm drain, so there's a logistical issue in getting it over there, but you should be able to see and lift that gully cover to check it.

I think we're back to broken underground pipes, personally.

Doozergirl

wallofbeans wrote: »

You're using lots of big words I don't know now... what's "differential settlement"?

It's what JimmyChanga was hinting at but I don't believe it applies to you as the single and double storey elements look to be of the same age.

Differential settlement is where an extension has different foundations to its host building and so the two buildings 'settle' onto their foundations at different rates and times, causing cracks to appear between the two elements. You'd expect it to follow the line of the join.

Doozergirl

wallofbeans wrote: »

That's great advice, thank you! I guess I'll have to wait and see what an engineer says, but if it's underground pipes then whose responsibility is that??

If the problem is before they reach any shared element, yours.

If it's at the point you start sharing with the neighbours, the water company's.

But that's just the pipes, not your house or the ground it sits on.