Structural Issue?

[Millwright]

Thanks for all your comments guys, they've been really helpful!

Seems like the most likely explanation based on your responses is it wasn't properly propped up when the work was originally done. In this case, am I right in saying the movement would all have happened while the work was being completed and in theory shouldn't move any further?

If the building wasn't properly propped up during the work, then if the building is settling, it will or should only go so far as to properly meet the RSJ, assuming what the RSJ is sat on is satisfactory.

 

[John D v2.0]

The steel only has a small footprint so the pressure (force per square mm) is a lot higher. The padstone has a high enough compressive strength to handle that.
The size of the padstone is specified to spread the force over enough area to reduce the pressure to something the normal bricks can handle.

To visualise it think of pressing a knife edge on some butter, or putting a small piece of wood over the butter and pressing the knife into that. The wood is the padstone.

 

[Doggit]

A lot of builders will create a "pad stone" by building a frame around the wall, then poring concrete into the frame. Depending on how wet the mix was, will then cause shrinkage as it dries, so they then pack slate between the pad

stone, and the RSJ. If the concrete mix is poor, it can crumble, and if they've just shoved a few bits of slate in, then that can crumble as well. Most Building surveyors look at the job when it's been finished, rather than the more important intermediate steps.

As to the cracks, as they are wider at the bottom, it suggests that the wall could be dropping, and so it might be worth looking under the floorboards by the wall, and see how well it's been supported. The RSJ may well have gone in perfectly well, but as Wessex says, it could well be that the wall above it wasn't supported properly when they put the RSJ in, and didn't pack the bricks above the RSJ, which would give rise to the problems the OP has, but there would only be deflection of the beam if they used an undersized one.

 

[000_dave_000]

Thanks Doggit, that makes sense and is definitely a (albeit less pleasing) possibility...

There is a floor board that's extremely creaky that I've just had a look at and there is a approx 20x30cm hole cut in it... I've had a look and took the following photos. Does this mean anything to anyone? I can see a crack along the beam that doesn't look good and where that metal part is doesn't look at a right angle...

If you need any more context to the photos let me know. Thanks again for all your help, definitely feel like I'm getting a better grasp of the different things that might be causing the problem

 

[Doggit]

The joist in the first photo isn't tight enough in to the hanger, and is very likely allowing the movement; packing this out night help. I normally cut a channel in to the top of the beam, and take the joist hangers over the top to give a bit more support, but this is just personal preference.

The crack in picture 2 doesn't look to serious, and shouldn't cause any serious issues - I assume that this is the crack you're referring to.

Picture 3 doesn't seem to suggest anything. Is there double plasterboard around the RSJs, or at least fire rated plasterboard to give half hour fire rating.

 

[000_dave_000]

The crack I was referring to was in the first photo, on the beam to the right of the image.

How serious is the joist not being tight enough and how difficult / expensive would something like this be to fix?

Sorry for what are probably really naive questions...

 

[tony1851]

If the crack runs not too far away from the bearing, it won't be serious.

 

[Doggit]

How long is the crack, and does it go through to the other side. Is this the beam that holds up the wall above it that's got the problems, because if it is, then you've got some upheaval to get to it, and then either strengthen or replace it, but I suspect you're going to have to lift the floor at some stage.

As to the loose joist, you may be able to set up a couple of wedges using a hard wood rather than pine, and then wack them into the gap with some glue to keep them in place.

The pre-cut hole in the floor, suggests the problems been looked at before, but as to the squeaky floorboards, how have they been fixed down, screws or straight nails. Altenatively, are there any noggins in the floor to stop the joists deflecting.

 

[000_dave_000]

The beam with the crack in it runs parallel to the wall that has the cracks from the corner of the door frame (it's about 40cm away) and perpendicular to the RSJ. It's also perpendicular to the wall with the door that sticks. It's about 30cm long that I can see and is much thicker by the joist.

By other side do you mean all the way through the beam, or the other side of the joist? It looks like it goes to the other side of the joist, but difficult to tell if it goes through the whole beam without lifting another floorboard.

They're nailed to the floor and I guess have been messed around quite a bit, with the hole etc thought I'd mention it though just in case it helped pinpoint the issue.

Lifting the floor doesn't sound good... how much would a job like that cost? Really not what I need just after buying my first house

 

[Doggit]

Do you have a long piece of something that's straight, that you can put on the ceiling underneath, to see if if it's bowing.

If the crack in the beam goes all the way through the beam, but is only about 30cm long, it may not be too serious, so you may have to look elsewhere.

This may seem a daft question, but what exactly is underneath the wall that's possibly dropping.

 

[000_dave_000]

The lounge is below, it was extended by knocking through an internal garage. This is why the RSJ was installed.

I've put a broom stick underneath it (that's the best I have...) and to be honest it does look like there could be some bowing. It's difficult to tell though.

Sounds like it's a no brainer to get a structural engineer in at this point. I realise there's only so much you can tell me without a proper visual inspection!

 

[Doggit]

Sorry, I meant underneath the floorboards, not the room below. If the RSJ is parallel to the wall that has the crack in it, but 40cm away from it, then what is supporting the wall itself.

I assume that the lower rsj is the one that goes across the garage, but what is the upper rsj for; is this the one supporting the other door issue. Is the deflection on the ceiling below in both directions by any chance.

 

[000_dave_000]

Sorry, I don't think I described this very well the first time round.

The lower RSJ is perpendicular to both the beam with the crack in it and the wall with the cracks from the corner of the door frames.

The upper RSJ is parallel to the beam with the crack in and probably half way between that beam and the wall with the cracks in (so 20 cm from each)

 

[Doggit]

Sorry Dave, you're on site, and that may make perfect sense to you, but we're sitting here trying to picture it in our mind, and perpendicular and parallel to what may have you, has no reference points for us to relate to.

The lower rsj will span the original wall that was removed, so work from there please. The rsjs in the second photo look okay, so the main question, is what is causing the deflection in the ceiling below, and are the walls in the room above, actually resting on anything solid.

I suspect you'll either need a structural engineer, or have a chat with building control, and find out who passed a questionable job.

 

[000_dave_000]

The internal garage that was knocked through had two walls, so it was a corner that was knocked through which presumably is why there are two RSJs.

The lower RSJ is in line with what would have been the back wall of the garage and continues beyond that to the next supporting wall.

The upper RSJ is in line with what would have been the left side of the garage. This is also in line with the wall that has cracks in it and the beam in the picture with a crack on it.

Thanks for your patience, it's clear my descriptions leave something to be desired! If it's still not clear I'll upload a diagram that might make more sense