My problem staircase

[Manny]

This is the staircase leading from the first to second floor of my Georgian terrace.



The small landing on the second floor is part cantilevered, the failing of which I think is the cause of the rotation of the top half of the staircase (the top half being the upper steps, facing you, that you can't seen in the picture below).



The problem is, I think, that the timber supporting the landing is failing and due to the lack of support the top part of the staircase is coming away from the wall.

Upper landing, second floor, you can see the extent of the sloping:



Here's the damage caused due to the stress of the stairs coming away from the wall:



From what I'm able to gather myself the joist just visible in this picture



forms the edge of the cantilevered upper landing. This joist in turn is supported (I assume) by this timber beam, which is partly visible from the first floor landing shown here:



The wall to which the wall string on the top half of the stairs is fixed is timber framed. Although I have yet to inspect the timbers myself I can confirm that the wall isn't brick. You can see in these pictures that some movement has occurred where the wall bulges out over the wall string. I guess this timber framed wall isn't really helping to support the staircase.



There is cracking to various degrees the whole way around the wall string.



I suppose the way forward is to find a decent carpenter who knows is way around old buildings.

If anyone has any observations from the photos, they'd certainly be most welcome. We're not using the second floor at the moment but the space is urgently required.

 

[Nigel Watts]

I suggest you ask a structural surveyor to have a look at this.

My 1840 house is a four storey semi with substantial brick outside walls. All the interior walls, except in the basement, are wood and plaster, and the house sags significantly in the middle. My second floor landing is also sloping, but luckily it has not damaged the staircase joinery.

My structural surveyor, after a very through examination, concluded that the house was structurally sound and that we need not worry. Further movement look place after works were done in the basement, but all seem to have stabilised now.

 

[Lime]

For your own peace of mind you need to have a structural engineer/surveyor examine this staircase as Nigel Watts suggests.

It is quite hard to put all the pictures together but I assume that the joist that is "just visible" also extends back through the supporting joist (shown from the 1st landing) into a wall?

 

[Penners]

As Nigel and Lime have said, a structural engineer is probably your best bet. The only other thing to consider is how much he will be able to see without being able to look at the structure of the timber frame around this staircase.

If you think it will be necessary to strip off some lath & plaster to enable the engineer to inspect the framing, then you could consider doing this first (ie: before employing an engineer) in order to do an initial inspection yourself. The reason for the displacement of the stircase might become obvious to you without your having to spend money on an engineer.

And if it isn't obvious, you'll have made the enginner's job easier.

I dislike the idea of destroying some lath and plaster, but there's no other way of getting to your timber frame.