Cracks in internal wall

dutchcloggie

Help me sleep at night (or scare me to death)....

There are cracks in the my bedroom wall. The wall is an internal wall between the 1st and 2nd bedroom. The cracks are on both sides and are staircase-like. They seem to originate from the corner of the doorpost. I am worried that this is a serious issue as I always thought staircase-shaped cracks are an indication of a very serious problem.

The wall in question is right on top of where the support beam should be (hopefully is) form when the lounge was knocked through to the dining room. This was presumably done aaaages ago. The house is a Victorian mid-terrace and my biggest fear is that the supporting beam is failing...?

When we bought the house back in April, I did notice the small cracks in the plasterwork on one side of the wall but they were not on both sides and only very small so I assumed they were just plaster cracks. But in the last few months, the cracks (still only in the plaster) have become more pronounced.

What could it be? Who can investigate this properly? A surveyor or a builder? It is keeping me awake at night.

Owain_Moneysaver

Extend an imaginary line at right angles to the crack and see where it points to - which may be the source of the problem.

If it points to the middle of the unsupported wall then the beam is flexing a bit but shouldn't fail assuming it was adequately designed in the first place.

If it points to the end(s) of the beam then the padstone or mortar the beam rests on may be compressing, or the load of the wall may be being transferred down to the foundation and that is sinking a bit at that point.

You'd really need a structural engineer (MIStructE) to investigate the cause and specify any remedial action.

Normal first action is to glue tell-tales over the crack and record how far and how quickly it is actually moving.

Chanes

When you bought it and you had a survey did that pick up anything to be concerned about with regard to cracks or movement?

dutchcloggie

Ah thanks. As I said, the cracks are very small at the moment, only marginally bigger than hairline cracks. The plaster is only just loose enough for me to wedge my nail under in some places.

Imagine a standard 2-bed Victorian terrace with a bedroom at the front and one at the back. The cracks start at the corner of the door frame of the bedroom at the front and travel downwards to the bottom corner of the wall on the other side of the room. On the other side of the wall (the spare room), the crack starts in the corner where (on the other side of the wall) the door frame is and they travel along the same path as the crack on the other side (if this makes sense). And in the hallway, there is also a crack that starts at the doorframe. SO it seems there is something happening there.

Mr.Generous

Cracks like that are the ones to worry about, something is dropping. My guess would be the supporting beam inadequate, but poster saying could be foundations is correct - it could be.

dutchcloggie

The survey wasn't worth the paper it was written on. There was no mention of anything about cracks. But then again, they were smaller then and had been painted over with red paint so were hardly noticable. Seeing as the man did not even move a sofa to check the source of damp, I am not expecting any come back if there is something structurally wrong. The report just said: get expert advice. For just about every thing in the house. Even the things he said were apparently in good order.

Owain_Moneysaver

dutchcloggie wrote: »

Ah thanks. As I said, the cracks are very small at the moment, only marginally bigger than hairline cracks. The plaster is only just loose enough for me to wedge my nail under in some places.

You don't have to start worrying until you can get a finger in.

dutchcloggie

Mr.Generous wrote: »

Cracks like that are the ones to worry about, something is dropping. My guess would be the supporting beam inadequate, but poster saying could be foundations is correct - it could be.

Ugh. Thanks. Now I feel a little bit sick. Would there be any comeback if it turns out the house is moving? I mean, the survey mentioned nothing, nor did the seller.

dutchcloggie

Owain_Moneysaver wrote: »

You don't have to start worrying until you can get a finger in.

That's what i always read but surely the fact that things are moving means something is going on. Something that was not going on before I bought the house. Would it not be wise to fix it before I can fit my finger in?

Owain_Moneysaver

All houses move a bit, and if it's a Victorian terrace the foundations might be a couple of rows of bricks on soil. Ground movement is often associated with leaky drains.

BRE Guidance on Cracks:

0 - Hairline cracks of less than about 0.1 mm which are classed as negligible. No action required.

1 - Fine cracks that can be treated easily using normal decoration. Damage generally restricted to internal wall finishes; cracks rarely visible in external brickwork. Typical crack widths up to 1 mm.

2 - Cracks easily filled. Recurrent cracks can be masked by suitable linings. Cracks not necessarily visible externally; some external repointing may be required to ensure weather-tightness. Doors and windows may stick slightly and require easing and adjusting. Typical crack widths up to 5 mm.

3 - Cracks that require some opening up and can be patched by a mason. Repointing of external brickwork and possibly a small amount of brickwork to be replaced. Doors and windows sticking. Service pipes may fracture. Weather-tightness often impaired. Typical crack widths are 5 to 15 mm, or several of, say, 3 mm.

In general, categories 0, 1 and 2 with crack widths up to 5 mm can be regarded as ‘aesthetic’ issues that require only redecoration. Categories 3 and 4 can generally be regarded as ‘serviceability’ issues, that is, they affect the weathertightness of the building and the operation of doors and windows.

Structural Movement - Is it really a problem